Eni SpA
COMPANY TECHNICAL STANDARD
ELECTRICAL SYSTEM DESIGN
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Document conforming with the version approved by the Facilities Technical
Authority of Eni. Uncontrolled copy.
ABSTRACT
This COMPANY Specification defines the minimum electrical design,
engineering and installation criteria to be used and the minimum
technical requirements for electrical equipment and materials to be
installed in both Eni onshore and offshore Oil & Gas facilities.
EINST
FATA
PLAPRE
S. Rugan, G. De
Vincolis, M.
Gorlini
14
June 2022
Final Issue
EINST
PRCO/B
13
July 2021
General revision
P. De Bartolomeis
12
February 2021
Final Issue
ELEE
P. De Bartolomeis
M. Gorlini
11
December 2020
Final Issue
ELEE
P. De Bartolomeis
M. Gorlini
10
July 2020
Final Issue
TEEL
P. De Bartolomeis
M. Gorlini
09
December 2019
Final Issue
TEEL
P. De Bartolomeis
M. Gorlini
08
June 2019
Final Issue
R. Scanferlini
P. De Bartolomeis
M. Gorlini
07
December 2018
Final Issue
R. Scanferlini
P. De Bartolomeis
M. Gorlini
06
May 2018
Final Issue
TEEL
R. Scanferlini
M. Gorlini
05
May 2017
Approved Issue
R. Scanferlini
C. R. Callari
M. Gorlini
04
October 2016
Approved Issue
R. Scanferlini
C. R. Callari
M. Gorlini
FATA
F. Duclocher
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 2 of 135
03
February 2009
General Revision
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October 2006
General Revision
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July 2003
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00
December 1995
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REV.
DATE
Reason for issue
Prepared
Verified
Approved
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 3 of 135
REVISION TRACKING
Rev. 14 (June 2022):
Rev. 14: current revision is of 135 pages
General revision
Rev. 13 (July 2021):
Rev. 13: current revision is of 93 pages
General revision
Date: July 2021
Rev. 12 (February 2021):
Rev. 12: current revision is of 85 pages
• Modified par. 1.1: “Scope”
• Modified par. 1.2.3: “Internal standardization references”
• Modified par. 2.1.2: “Specific definition”
• Modified par. 2.2: “Symbols and abbreviations”
• Modified par. 2.6.1: “Project technical review and assessment”
• Modified TABLE 4: “Maximum current and rated power on switchgears bus-bars”
• Modified par. 2.7.5.1: “Medium voltage systems”
• Modified par. 2.8.5.1: “General”
• Modified par. 2.8.5.2: “Dry type power transformers”
• Modified par. 2.8.5.3: “Oil immersed power transformers”
• Modified par. 2.8.7.7: “Selection of UPS autonomy”
• Deleted Table 11 “UPS autonomy”
• Modified par. 2.8.9.1: “Asynchronous motors”
• Modified par. 2.8.11.1: “General requirements”
• Added par. 2.8.11.10: “General requirements for CPR cables (applicable for EU
projects)”
• Modified par. 2.8.12: “Overhead transmission lines”
• Added par. 2.8.14: “Neutral earthing resistors”
• Added par. 2.8.15: “Electric process heaters”
• Added par. 2.8.16: “CAS levels”
• Modified par. 2.9.8: “Electrical resistance trace heating”
• Added par. 2.9.8.1: “Electrical resistance trace heating following IEC/IEEE 6007930-1 and IEC/IEEE 60079-30-2”
• Added par. 2.9.8.2: “Electrical resistance trace heating following IEC 62395-1 and
IEC 62395-2”
• Modified par. 2.9.9: “Junction boxes”
• Modified par. 2.10.1.2: “Transformer bay”
• Modified par. 3.3: “Protection against explosion and fire hazard”
• Modified par. 3.4: “Protective device”
• Modified par. 3.7.2: IEC 61892-4 “Cables”
• Added par. 3.7.5: “CPR Cables”
• Added par. 3.13: “Submarine cables”
Date February 2021
Rev. 11 (December 2020):
Rev. 11: current revision is of 78 pages
• Modified par. 1.1: “Scope”
• Modified par. 1.2.3: “Internal standardization references”
• Modified par. 2.1.1: “General definition”
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 4 of 135
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Modified par. 2.1.2: “Specific definition”
Modified par. 2.2: “Symbols and abbreviations”
Modified par. 2.4: “Operative environment”
Modified par. 2.6.1: “Project technical review and assessment”
Modified par. 2.6.4: “Certificates, declarations and test reports”
Modified par. 2.6.5: “Energy efficiency”
Modified par. 2.7.1: “General”
Modified Table 1: “Loads Classification”
Modified par. 2.7.2.2: “Load balance”
Modified Table 2: “Rated Voltage and maximum voltage levels for the equipment”
Modified Table 3: “Criteria for voltage levels selection”
Modified par. 2.7.2.6: “Voltage and frequency variation”
Modified par. 2.7.2.7: “Maximum value of rated current on switchgears bus-bars”
Modified Table 4: “Maximum current and rated power on switchgears bus-bars”
Modified par. 2.7.3: “Harmonic distortion”
Modified par. 2.7.5: “Neutral earthing”
Modified par. 2.7.7: “Electrical protection”
Modified par. 2.7.7.1: “Short circuits protections”
Modified par. 2.7.7.2: “Overloads protections”
Modified par. 2.7.8: “Intertripping and interlocking”
Modified par. 2.7.9.2: “Protection against lightning”
Modified par. 2.7.10: “Emergency electrical system”
Modified par. 2.7.11: “Black start requirements”
Modified par. 2.7.12: “Motor starting system selection”
Modified par. 2.7.15: “Safe shut down of machinery”
Modified par. 2.8.1: “Insulation classes and temperature rises”
Modified Table 7: “Electric machines: classes of insulation and over-temperatures”
Modified par. 2.8.2: “Protection against explosion and fire hazards”
Modified par. 2.8.3.1: “External network connection”
Modified Table 8: “Selection criteria for RICE Diesel/Gas Generator”
Modified par. 2.8.4: “Switchgears” and subparagraphs
Modified par. 2.8.5: “Power transformers “ and subparagraphs
Modified par. 2.8.6: “Inductive shunt reactors”
Added par. 2.8.6.1: “Dry type reactors”
Added par. 2.8.6.2: “Oil immersed reactors”
Modified par. 2.8.7.1: “AC Uninterruptible Power Supply System”
Modified par. 2.8.7.2: “Selection of UPS scheme”
Modified par. 2.8.7.6: “Cut off battery box”
Modified par. 2.8.8: “Storage batteries”
Modified par. 2.8.9.3: “Motors supplied by power converters”
Modified par. 2.8.11: “Cables, wires and accessories”
Modified par. 2.8.11.3: “Battery cables”
Modified par. 2.8.11.4: “Cable system categories”
Modified par. 2.8.11.7: “Mechanical protection of cables”
Modified par. 2.8.11.8: “Cables screen”
Modified par. 2.8.11.9: “Minimum and maximum conductor section”
Modified par. 2.9.1: “Lighting system”
Modified par. 2.9.1.3: “Emergency escape lighting (EEL)”
Modified par. 2.9.2: “Motor Control Station”
Modified par. 2.9.3: “Power and convenience sockets”
Modified par. 2.9.4: “Conduits”
Modified par. 2.9.5: “Cable trays”
Modified par. 2.9.7: “Multi-cable Transit (MCT)”
Modified par. 2.10.1: “Electrical rooms”
Modified par. 2.10.1.2: “Transformer bay”
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 5 of 135
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Modified par. 2.10.1.3: “Battery room”
Modified par. 2.10.2: “Cabling and wiring”
Modified par. 2.10.4: “Earthing system”
Modified par. 2.10.4.1: “HV substations”
Modified par. 2.10.4.2: “MV and LV substations”
Modified par. 2.10.4.4: “Metal structures, equipment and interconnecting”
Modified par. 3.1: “General”
Modified par. 3.2: “Neutral earthing”
Modified par. 3.3: “Protection against explosion and fire hazard”
Modified par. 3.4: “Protective device”
Modified par. 3.5: “Essential power generation system”
Deleted par. 3.6: “LV switchgear”
Modified par. 3.8.2: “IEC 61892-4 “Cables”
Modified par. 3.11: “Lighting”
Modified par. 3.12: “Navigation & aeronautical aids system for offshore platforms
and floaters”
Date: December 2020
Rev. 10 (July 2020):
Rev. 10: current revision is of 64 pages
• Modified par. 2.2 “Symbols and abbreviations”
• Modified Table 7 “Electric machines: Classes of insulation and over-temperatures”
• Modified par. 2.8.9.1: “Asynchronous motors”
• Deleted par. 2.8.9.4: “Degree of protection”
• Modified par. 2.8.13: “Decorative colours for electrical equipment”
Date July 2020
Rev. 09 (December 2019):
Rev. 09: current revision is of 63 pages
• Modified note to Table 3 “Criteria for voltage levels selection”
• Modified par. 2.7.2.5 “Voltage drops”
• Modified par. 2.7.10 “Emergency electrical system”
• Modified par. 2.7.13 “Electrical Management System (EMS)”
• Modified par. 2.8.2 “Protection against explosion and fire hazards”
• Modified par. 2.8.3 “Power generation systems”
• Modified par. 2.8.3.1 “External network connection”
• Modified par. 2.8.3.2 “Generation system”
• Modified par. 2.8.4.1 “MV switchgears”
• Modified par. 2.8.4.2.3 “Auxiliary Services Panel and Lightning Distribution Panel”
• Modified par. 2.8.5.1 “General”
• Modified par. 2.8.5.3 “Oil immersed type power transformer”
• Modified par. 2.8.5.4 “Selection criteria of power transformers”
• Modified par. 2.8.7.2 “Selection of UPS scheme”
• Modified par. 2.8.7.4 “Selection of UPS battery voltage”
• Modified par. 2.8.7.6 “Cut off battery box”
• Modified note to Table 11 “UPS autonomy”
• Modified par. 2.8.8 “Storage batteries”
• Modified par. 2.8.9.2 “Synchronous motors”
• Modified par. 2.8.9.3 “Motors supplied by Variable Speed Drives”
• Deleted par. 2.8.9.4 “Direct current motors”
• Modified par. 2.8.10 “Electrical Management System (EMS)”
• Deleted par. 2.8.10.1 “Electrical Control System ECS”
• Deleted par. 2.8.10.2 “Power Management System PMS”
• Deleted par. 2.8.10.3 “Load Shedding System LSS”
• Modified par. 2.8.11.1 “General requirements”
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 6 of 135
• Modified par. 2.8.11.2 “Cable sizing criteria”
• Modified par. 2.8.11.3 “Battery cables”
• Deleted par. 2.8.11.5 “Installation factor”
• Modified par. 2.8.11.8 “Mechanical protection of cables”
• Modified note to Table 14 “Low Voltage ONSHORE and OFFSHORE systems”
• Modified par. 2.9.1 “Lighting system”
• Modified par. 2.9.1.1 “Normal lighting (NL)”
• Modified par. 2.9.1.1.1 “Power supply and electrical distribution (NL)”
• Modified par. 2.9.1.2 “Emergency lighting (EL)”
• Modified par. 2.9.1.2.1 “Power supply and electrical distribution (EL)”
• Modified par. 2.9.1.3.1 “Lighting fixture with incorporated battery”
• Modified par. 2.9.1.4 “Lighting inside the buildings”
• Modified par. 2.9.4 “Conduits”
• Modified par. 2.9.5 “Cable trays”
• Modified par. 2.9.9 “Junction boxes”
• Modified par. 2.10.1 “Electrical rooms”
• Modified Table 16 “Switchboards and electrical equipment minimum free space”
• Modified par. 2.10.1.1 “Generator room”
• Modified par. 2.10.1.2 “Transformer bay”
• Modified par. 2.10.3 “Lighting system”
• Modified par. 2.10.4.4 “Metal structures, equipment and interconnecting”
• Modified par. 2.10.4.6 “Metal fences”
• Modified par. 2.10.4.8 “Cathodically protected structures”
• Modified Table 17 “Type, quantity and position of the sockets”
• Modified par. 3.1 “General”
• Modified par. 3.3 “Protection against explosion and fire hazard”
• Modified par. 3.8 “Cables”
• Modified par. 3.8.3 “IEC 61892-6 Installation”
• Modified par. 3.8.4 “Other requirements”
Date December 2019
Rev. 08 (June 2019):
Rev. 08: current revision is of 64 pages
• Modified par. 1.2.3 “Internal standardization references”
• Modified par. 2.2 “Symbols and abbreviations”
• Modified Table 1 “Loads classification”
• Modified Table 3 “Criteria for voltage levels selection”
• Modified Table 4 “Maximum current and rated power on switchgears bus-bars”
• Modified par. 2.7.5.3 “AC UPS systems”
• Modified par. 2.7.7 “Electrical protection”
• Modified par. 2.7.10 “Emergency electrical system”
• Modified par. 2.7.11 “Black start requirements”
• Added par. 2.7.15 “Safe shut down of machinery”
• Modified par. 2.8.3.2 “Generation system”
• Modified par. 2.8.4 “Switchgears”
• Modified par. 2.8.4.2 “LV Switchgears”
• Modified par. 2.8.4.2.3 “Auxiliary Services Panel and Lighting Distribution Panel”
• Added par. 2.8.4.3 “Spares on switchgear”
• Modified par. 2.8.5.1 “General”
• Deleted Table 10 “Max rated power of dry type transformers”
• Added par. 2.8.5.4 “Selection criteria of power transformers”
• Modified par. 2.8.7.1 “AC Uninterruptible Power Supply System”
• Modified par. 2.8.7.2 “Selection of UPS scheme”
• Modified par. 2.8.11 “Cables, wires and accessories”
• Added par. 2.8.11.1 “General requirements”
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 7 of 135
• Modified par. 2.9.1 “Lighting system”
• Modified par. 2.9.2 “Motor Control Station”
• Modified par. 2.9.5 “Cable trays”
• Added par. 2.9.9 “Junction boxes”
• Modified par. 2.10.3 “Lighting system”
• Modified par. 2.10.4.3 “Electric equipment”
• Modified par. 2.10.4.4 “Metal structures, equipment and interconnecting”
• Modified par. 2.10.4.6 “Metal fences”
• Modified par. 3.1 “General”
• Modified par. 3.2 “State of neutral”
• Modified par. 3.5 “Essential power generation system”
• Modified par. 3.8 “Cables”
• Added par. 3.8.1 IEC 61892-2 “System design”
• Added par. 3.8.2 IEC 61892-4 “Cables”
• Added par. 3.8.3 IEC 61892-6 “Installation”
• Added par. 3.8.4 “Other requirements”
• Modified par. 3.9 “Earthing and bonding”
• Modified par. 3.11 “Lighting”
• Added par. 3.13 “Swivel and turret”
Date June 2019
Rev. 07 (December 2018):
Rev. 07: Current revision is of 59 pages
• Change main title from “Electrical Power System” to “Electrical System Design”
• Some paragraphs and tables have been renumbered
• Deleted
reference
to
COMPANY
standard
20210.ENG.ELE.PRG,
20218.ENG.ELE.PRG
• Deleted reference to COMPANY standard 20249.ENG.ELE.PRG
• Deleted reference to COMPANY standard 20209.ENG.ELE.PRG
• Deleted Table 7 “Selection criteria and comparative table”
• Added Table 5 “System earthing - selection guide”
• Added Table 19 “State of neutral - selection guide”
• Added Table 13 “Medium voltage onshore system”
• Added Table 14 “Medium voltage offshore system”
• Added Table 15 “Low voltage onshore and offshore systems”
• Modified Table 1 “Loads Classification”
• Modified Table 3 “Criteria for voltage levels selection”
• Modified Table 5 “Guideline for single and double radial configuration selection”
• Modified Table 6: “Electric machines: Classes of insulation and over-temperatures”
• Modified Table 12 “UPS autonomy”
• Modified par. 2.6.1 “Project technical review and assessment”
• Modified par. 2.6.5 “Energy efficiency”
• Modified par. 2.7.2.2 “Load balance”
• Modified par. 2.7.2.5 “Voltage drops”
• Modified par. 2.7.2.6 “Voltage and frequency variation”
• Modified par. 2.7.3 “Harmonics distortion”
• Modified par. 2.7.5.1 “Medium Voltage systems”
• Modified par. 2.7.5.2 “LV systems”
• Modified par. 2.7.5.3 “UPS systems”
• Modified par. 2.7.7 “Electrical protection”
• Modified par. 2.7.7.1 “Short circuit protections”
• Modified par. 2.7.9.1 “Protection against lightning” and par. 2.7.9.2 “Earthing
system” and order of paragraphs inverted
• Modified par. 2.7.10 “Emergency electrical system”
• Modified par. 2.7.11 “Black start requirements”
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 8 of 135
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Modified par. 2.7.13 “Electrical Management System (EMS)”
Modified par. 2.7.14 “Electrical studies and reports”
Modified par. 2.8.1 “Insulation classes and overtemperatures”
Modified par. 2.8.2 “Protection against explosion and fire hazards”
Modified par. 2.8.3 “Power generation systems”
Modified par. 2.8.3.1 “External network connection”
Modified par. 2.8.3.2 “Generation system”
Modified par. 2.8.4.1 “MV Switchgears”
Modified par. 2.8.4.2 “LV Switchgears”
Modified par. 2.8.6 “Inductive shunt reactors”
Modified par. 2.8.7.1 “AC Uninterruptible Power Supply System”
Modified par. 2.8.7.2 “Selection of UPS scheme”
Modified par. 2.8.7.3 “Selection of UPS incoming and outgoing system”
Modified par. 2.8.7.7 “Selection of UPS autonomy”
Modified par. 2.8.8 “Storage batteries”
Modified par. 2.8.9.1 “Asynchronous motors”
Modified par. 2.8.9.3 “Motors supplied by Variable Speed Drives”
Added par. 2.8.9.5 “Degree of protection”
Modified par. 2.8.10 “Electrical Management System (EMS)”
Modified par. 2.8.10.1 “Electrical Control System (ECS)”
Modified par. 2.8.10.2 “Power Management System (PMS)”
Modified par. 2.8.10.3 “Load Shedding System (LSS)”
Modified par. 2.8.11 “Cables, wires and accessories”
Added par. 2.8.11.1 “Cable sizing criteria”
Added par. 2.8.11.2 “Battery cables”
Added par. 2.8.11.3 “Cable system with IT distribution”
Added par. 2.8.11.4 “Installation factor”
Added par. 2.8.11.5 “Cables in parallel”
Added par. 2.8.11.6 “Control/command cables”
Added par. 2.8.11.7 “Mechanical protection of cables”
Added par. 2.8.11.8 “Cables shielding”
Added par. 2.8.11.9 “Minimum and maximum conductor section”
Modified par. 2.8.12 “MV Overhead transmission lines”
Modified par. 2.9.1 “Lighting system”
Added par. 2.9.1.1 “Normal lighting (NL)”
Added par. 2.9.1.1.1 “Power supply and electrical distribution (NL)”
Added par. 2.9.1.2 “Emergency lighting (EL)”
Added par. 2.9.1.2.1 “Power supply and electrical distribution (EL)”
Added par. 2.9.1.3 “Emergency escape lighting (EEL)
Added par. 2.9.1.3.1 “Lighting fixture with incorporated battery”
Added par. 2.9.1.3.2 “Power supply and electrical distribution (EEL)”
Added par. 2.9.1.4 “Lighting inside the buildings”
Added par. 2.9.1.5 “Illumination level”
Modified par. 2.9.4 “Conduits”
Modified par. 2.9.5 “Cable trays”
Modified par. 2.9.6 “Cable glands”
Added par 2.9.7 “Multi-cable transit (MCT)”
Modified par. 2.9.8 “Electrical heat tracing system”
Modified par. 2.10.1 “Electrical rooms”
Modified par. 2.10.1.3 “Battery room”
Modified par. 2.10.2 “Cabling and wiring”
Modified par. 2.10.3 “Lighting system”
Added par. 2.10.4 “Earthing system”
Added par. 2.10.5 “Lightning system”
Modified par. 2.10.5 “Power and convenience sockets”
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 9 of 135
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Modified par. 2.12.1 “General”
Modified par. 2.12.2 “State of neutral (floaters)”
Modified par. 2.12.3 “Protection against explosion and fire hazard”
Added par. 3.4 “Protective device”
Modified par. 2.12.4 “Essential power generation system”
Modified par. 2.12.7 “Cables”
Modified par. 2.12.8 “Earthing and bonding”
Modified par. 2.12.9 “Navigation & aeronautical aids system for offshore
platforms”
• Deleted par. 2.12.10 “Living quarters”
• Deleted par. 2.12.11 “Service module”
• Added par. 3.10 “Lightning protection system”
• Added par. 3.11 “Lighting”
Date December 2018
Rev. 06 (May 2018):
Rev. 06: Actual revision is of 51 pages
• Updated code of Company standards
• Par 2.6.5 “Energy efficiency” - Delete reference company standard
27984.ENG.GEN.PRG, 28022.ENG.GEN.PRG, 28001.ENG.GEN.PRG
• General revision par 2.8.3 “Power generation systems” - Delete reference
company standard 20211.ENG.ELE.PRG, 20230.ENG.ELE.STD.
• Par 2.9.7 Electrical heat tracing system – Delete reference company standard
06733.VAR.ETI.SDS
• Delete par 2.10.6 “Electrical heat tracing”
• Added decorative colors reference for electrical equipment (Par 2.11)
Date May 2018
Rev. 05 (May 2017):
Rev. 05: Actual revision is of 48 pages
Requirements of FPSO added;
Exclusion added
Earthing philosophy for MV system modified
Requirements for HVAC panels added
PTC has been substituted by PT100 in the power transformer
PT100 for MV motors added
Battery room requirements added
Lighting system controls added
This revision supersedes:
•
•
20233.VOF.ELE.PRG FPSO Electrical system
20221.PKG.GEN.SDS Auxiliary plants in prefabricated cabins for electric
machinery and equipment
• 20215.PKG.ETI.SDS Electric And Instrumentation Plants Included In Package
Supplies
Date: May 2017
Rev. 04 (October 2016):
Rev. 04: Actual revision is of 49 pages
General Revision
Date: October 2016
Rev. 03 (February 2009):
Rev. 03: Actual revision is of 48 pages
General Revision
ENGINEERING COMPANY STANDARD
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Date: February 2009
Rev. 02 (October 2006):
Rev. 02: Actual revision is of 40 pages
General Revision
Date: October 2006
Rev. 01 (July 2003):
Rev. 01: Actual revision is of 34 pages
Issue for normative references revision and contents conformity
Date: July 2003
Rev. 00 (December 1995):
Rev. 00: Actual revision is of 28 pages
First issue in conformity with EEC directives
This specification replaces and supersedes the following specification:
06678.VAR.ELE.SPC General specification - electrical power system
Date: December 1995
INFORMATION REQUEST
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or the Digital version at:
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External user shall refer to the Project Engineer Manager.
For information about the content of this standard, please refer to persons mentioned on first
page or to Company Standard Team (mbxc&st@eni.com).
ENGINEERING COMPANY STANDARD
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INDEX
1
GENERAL
14
1.1
SCOPE
14
1.2
NORMATIVE REFERENCES
14
2
2.1
1.2.1
International, IOGP and European standards
14
1.2.2
Laws, Decrees, Directives
32
1.2.3
Internal standardization references
32
FUNCTIONAL REQUIREMENTS
DEFINITIONS
39
39
2.1.1
General definitions
39
2.1.2
Specific definitions
40
2.2
SYMBOLS AND ABBREVIATIONS
42
2.3
GRAPHIC, SYMBOLS, CODES AND IDENTIFICATIONS TAG
44
2.4
OPERATIVE ENVIRONMENT
44
2.5
MEASUREMENT UNITS
44
2.6
DESIGN AND ENGINEERING PRINCIPLES
45
2.7
2.8
2.6.1
Protection against explosion and fire hazard
45
2.6.2
Certificates, declarations and test reports
45
ELECTRICAL SYSTEM DESIGN
45
2.7.1
Electrical loads classification and load balance
45
2.7.2
Power factor
50
2.7.3
Harmonic distortion
51
2.7.4
Neutral earthing
51
2.7.5
Power distribution configuration
57
2.7.6
Electrical protection
57
2.7.7
Inter-tripping and interlocking
59
2.7.8
Earthing and lightning protection system
60
2.7.9
Emergency electrical system
61
2.7.10
Black start requirements
63
2.7.11
Motor starting system selection
64
2.7.12
Electrical Management System (EMS)
64
2.7.13
Electrical studies and reports
64
2.7.14
Transformer impedances
64
2.7.15
Electrical system for offshore facilities
64
ELECTRICAL EQUIPMENT DESIGN AND SELECTION CRITERIA
ENGINEERING COMPANY STANDARD
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64
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2.8.1
Selection of protection methods against explosion and fire hazards
64
2.8.2
Power generation systems
66
2.8.3
Switchgears
69
2.8.4
Power transformers
75
2.8.5
Reactors
81
2.8.6
UPS equipment and batteries
83
2.8.7
Storage batteries
91
2.8.8
Rotating electrical machines
94
2.8.9
Cables, wires and accessories
98
2.8.10
Overhead transmission lines
105
2.8.11
Surface treatments of electrical equipment
105
2.8.12
Neutral earthing resistors
106
2.8.13
Electric process heaters
108
2.8.14
Safe shutdown of machinery
108
2.8.15
Adjustable Speed Electrical Power Drive Systems
108
2.8.16
Navigation & aeronautical aids system for offshore platforms and floaters
110
2.8.17
Swivel and turret
110
2.8.18
Submarine cables
111
2.9
BULK MATERIALS
113
2.9.1
Lighting system
113
2.9.2
Motor Control Station
117
2.9.3
Power and convenience sockets
118
2.9.4
Conduits
118
2.9.5
Cable ladders and cable trays
118
2.9.6
Cable glands
120
2.9.7
Multi-cable Transit (MCT)
120
2.9.8
Electrical resistance trace heating
120
2.9.9
Junction boxes
123
2.10
INSTALLATION REQUIREMENTS
123
2.10.1
Electrical room building
123
2.10.2
Cabling and wiring
127
2.10.3
Lighting system
128
2.10.4
Earthing system
129
2.10.5
Lightning protection system
135
2.10.6
Aviation warning lighting
135
2.10.7
Power and convenience sockets
135
ENGINEERING COMPANY STANDARD
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ENGINEERING COMPANY STANDARD
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1
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GENERAL
1.1
SCOPE
This COMPANY Standard defines the minimum electrical design, engineering and installation
criteria to be used and the minimum technical requirements for electrical equipment and
materials to be installed in both Eni onshore and offshore Oil & Gas facilities.
This standard does not cover the following:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Power generation plant exclusively connected to an external grid;
HV substations;
Cable transmission lines with Um>52 kV;
Subsea systems;
Umbilicals;
Downstream plants;
Renewable power plants;
Accommodation camps;
Offices outside of plant areas;
Drilling rigs and associated users;
Jetties;
Submersible pump motors;
Electric firefighting pumps;
Erection, commissioning and start-up;
Facilities following North American standards.
1.2
NORMATIVE REFERENCES
1.2.1
International, IOGP and European standards
1.2.1.1 General
The electrical system and its components shall comply with IEC standards, apart from
exceptions indicated in the present document.
Equipment to be installed in the European Union Member States shall have the appropriate ‘CE’
marking.
The latest edition of each standard shall be used, together with issued amendments,
supplements and revisions.
New revisions and updates of standards, issued during an activity or project, shall be
considered if having safety or environmental impacts.
For facilities outside Italy, national standards shall be applied if required by the authorities in
the country of installation.
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If a standard number is followed by the words “all parts” or “series”, it shall include all parts of
the standard, including Technical Specifications (TS) and Technical Reports (TR).
If a standard has been withdrawn with a replacement, it shall be substituted by the standard
that has replaced it.
If a standard has been withdrawn without replacement, it shall not be applied.
If a standard has been withdrawn without replacement, the subject originally covered by it
shall be replaced with technical requirements and references to other applicable standards, to
be included in Electrical Design Criteria or in Technical Specifications issued for the project.
If a standard refers to an agreement between parties, the technical requirements applied to
the project shall be defined in Electrical Design Criteria or in Technical Specifications.
The international or national standards referred in other international or national standards, or
in IOGP documents, or COMPANY standards, shall be considered mandatory at the same level
of the standard (or IOGP document) that refers to them, even if not explicitly mentioned in the
present specification.
The IOGP specifications mentioned in the present standard shall be considered integral part of
it.
1.2.1.2 International and IOGP standards
The electrical system shall comply with IEC 60034 (all parts) “Rotating electrical machines”.
The electrical system shall comply with IEC 60038 "IEC standard voltages".
The electrical system shall comply with IEC 60051 (all parts) "Direct acting indicating analogue
electrical measuring instruments and their accessories".
The electrical system shall comply with IEC 60060 (all parts) "High-voltage test techniques".
The electrical system shall comply with IEC 60068 (all parts) "Environmental testing".
The electrical system shall comply with IEC 60071-1 "Insulation co-ordination – Part 1:
Definitions, principles and rules".
The electrical system shall comply with IEC 60071-2 "Insulation co-ordination – Part 2:
Application guidelines".
The electrical system shall comply with IEC 60072 (all parts) "Dimensions and output series for
rotating electrical machines".
The electrical system shall comply with IEC 60073 "Basic and safety principles for manmachine interface, marking and identification – Coding principles for indicators and actuators".
ENGINEERING COMPANY STANDARD
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The electrical system shall comply with IEC 60076 (all parts) "Power transformers".
The electrical system shall comply with IEC 60079 (all parts) "Explosive atmospheres".
The electrical system shall comply with IEC/IEEE 60079-30-1 "Explosive atmospheres – Part
30-1: Electrical resistance trace heating – General and testing requirements".
The electrical system shall comply with IEC/IEEE 60079-30-2 "Explosive atmospheres – Part
30-2: Electrical resistance trace heating – Application guide for design, installation and
maintenance".
The electrical system shall comply with IEC 60085 "Electrical insulation – Thermal evaluation
and designation".
The electrical system shall comply with IEC 60099 (all parts) "Surge arresters".
The electrical system shall comply with IEC 60146 (all parts) "Semiconductor Converters".
The electrical system shall comply with IEC 60204-1 "Safety of machinery – Electrical
equipment of machines – Part 1: General requirements".
The electrical system shall comply with IEC 60204-11 "Safety of machinery – Electrical
equipment of machines – Part 11: Requirements for equipment for voltages above 1 000 V AC
or 1 500 V DC and not exceeding 36 kV".
The electrical system shall comply with IEC 60214-1 "Tap-changers – Part 1: Performance
requirements and test methods".
The electrical system shall comply with IEC/IEEE 60214-2 "TAP-changers – Part 2: Application
guidelines".
The electrical system shall comply with IEC 60228 "Conductors of insulated cables".
The electrical system shall comply with IEC 60255 (all parts) "Measuring relays and protection
equipment ".
The electrical system shall comply with IEC 62259 "Secondary cells and batteries containing
alkaline or other non-acid electrolytes – Nickel-cadmium prismatic secondary single cells with
partial gas recombination".
The electrical system shall comply with IEC 60276 "Carbon brushes, brush holders,
commutators and slip-rings – Definitions and nomenclature".
The electrical system shall comply with IEC 60282-1 "High-voltage fuses – Part 1: Currentlimiting fuses".
The electrical system shall comply with IEC 60269-4 "Low-voltage fuses – Part 4:
Supplementary requirements for fuse-links for the protection of semiconductor devices".
ENGINEERING COMPANY STANDARD
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The electrical system shall comply with IEC 60269-6 "Low-voltage fuses - Part 6:
Supplementary requirements for fuse-links for the protection of solar photovoltaic energy
systems".
The electrical system shall comply with IEC 60270 "High-voltage test techniques – Partial
discharge measurements".
The electrical system shall comply with IEC 60287-1-1 "Electric cables – Calculation of the
current rating – Part 1-1: Current rating equations (100 % load factor) and calculation of
losses – General".
The electrical system shall comply with IEC 60304 "Standard Colours for Insulation for Low
Frequency Cables and Wires".
The electrical system shall comply with IEC 60529 "Degrees of protection provided by
enclosures (IP Code)".
The electrical system shall comply with IEC 60598 (all parts) "Luminaires".
The electrical system shall comply with IEC 60721 (all parts) "Classification of environmental
conditions".
The electrical system shall comply with IEC 60811 (all parts) "Electric and optical fibre cables –
Test methods for non-metallic materials".
The electrical system shall comply with IEC 60896-11 "Stationary lead-acid batteries – Part
11: Vented types – General requirements and methods of tests".
The electrical system shall comply with IEC 60896-21 "Stationary lead-acid batteries – Part
21: Valve regulated types – Methods of test".
The electrical system shall comply with IEC 60896-22 "Stationary lead-acid batteries – Part
22: Valve regulated types – Requirements".
The electrical system shall comply with IEC 60909 (all parts) "Short-circuit currents in threephase a.c. systems".
The electrical system shall comply with IEC 60331 (all parts) "Tests for electric cables under
fire conditions – Circuit integrity".
The electrical system shall comply with IEC 60332 (all parts) "Tests on electric and optical fibre
cables under fire conditions".
The electrical system shall comply with IEC 60445 "Basic and safety principles for manmachine interface, marking and identification – Identification of equipment terminals,
conductor terminations and conductors".
ENGINEERING COMPANY STANDARD
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The electrical system shall comply with IEC 60519-1 "Safety in installations for electroheating
and electromagnetic processing – Part 1: General requirements".
The electrical system shall comply with IEC 60519-10 "Safety in electroheating installations –
Part 10: Particular requirements for electrical resistance trace heating systems for industrial
and commercial applications".
The electrical system shall comply with IEC 60533 "Electrical and electronic installations in
ships – Electromagnetic compatibility (EMC) – Ships with a metallic hull".
The electrical system shall comply with IEC 60617 DATABASE "Graphical symbols for
diagrams".
The electrical system shall comply with IEC 60622 "Secondary cells and batteries containing
alkaline or other non-acid electrolytes – Sealed nickel-cadmium prismatic rechargeable single
cells".
The electrical system shall comply with IEC 60623 "Secondary cells and batteries containing
alkaline or other non-acid electrolytes – Vented nickel-cadmium prismatic rechargeable single
cells".
The electrical system shall comply with IEC 60644 "Specification for high-voltage fuse-links for
motor circuit applications".
The electrical system shall comply with IEC 60664-1 "Insulation coordination for equipment
within low-voltage systems – Part 1: Principles, requirements and tests".
The electrical system shall comply with IEC 60684 (all parts) "Flexible insulating sleeving".
The electrical system shall comply with IEC 60695-11-10 "Fire hazard testing – Part 11-10:
Test flames – 50 W horizontal and vertical flame test methods".
The electrical system shall comply with IEC 60695-11-20 "Fire hazard testing – Part 11-20:
Test flames – 500 W flame test method".
The electrical system shall comply with IEC 60754-1 "Test on gases evolved during combustion
of materials from cables – Part 1: Determination of the halogen acid gas content".
The electrical system shall comply with IEC 60754-2 "Test on gases evolved during combustion
of materials from cables – Part 2: Determination of acidity (by pH measurement) and
conductivity".
The electrical system shall comply with IEC/TS 60815-1 "Selection and dimensioning of highvoltage insulators intended for use in polluted conditions – Part 1: Definitions, information and
general principles".
The electrical system shall comply with IEC 60885-2 "Electrical test methods for electric
cables. Part 2: Partial discharge tests".
ENGINEERING COMPANY STANDARD
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The electrical system shall comply with IEC 60885-3 "Electrical test methods for electric cables
- Part 3: Test methods for partial discharge measurements on lengths of extruded power
cables".
The electrical system shall comply with IEC 60891 "Photovoltaic devices – Procedures for
temperature and irradiance corrections to measured I-V characteristics".
The electrical system shall comply with IEC 60904 (all parts) "Photovoltaic devices".
The electrical system shall comply with IEC 60947 (all parts) "Low-voltage switchgear and
controlgear".
The electrical system shall comply with IEC 60986 "Short-circuit temperature limits of electric
cables with rated voltages from 6 kV (Um = 7,2 kV) up to 30 kV (Um = 36 kV)".
The electrical system shall comply with IEC 61000 (all parts) "Electromagnetic compatibility
(EMC)".
The electrical system shall comply with IEC 61034-1 "Measurement of smoke density of cables
burning under defined conditions – Part 1: Test apparatus".
The electrical system shall comply with IEC 61034-2 "Measurement of smoke density of cables
burning under defined conditions – Part 2: Test procedure and requirements".
The electrical system shall comply with IEC 61131 (all parts) "Programmable controllers".
The electrical system shall comply with IEC 61310 (all parts) "Safety of machinery –
Indication, marking and actuation".
The electrical system shall comply with IEC 61363-1 "Electrical installations of ships and
mobile and fixed offshore units – Part 1: Procedures for calculating short-circuit currents in
three-phase a.c.".
The electrical system shall comply with IEC 61204 (all parts) "Low-voltage power supply
devices, d.c. output – Performance characteristics".
The electrical system shall comply with IEC 61215 (all parts) "Terrestrial photovoltaic (PV)
modules – design qualification and type approval".
The electrical system shall comply with IEC 61378-1 "Converter transformers – Part 1:
Transformers for industrial applications".
The electrical system shall comply with IEC 61378-3 "Converter transformers – Part 3:
Application guide".
The electrical system shall comply with IEC 61400 (all parts) "Wind energy generation
systems".
ENGINEERING COMPANY STANDARD
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The electrical system shall comply with IEC 61427-1 "Secondary cells and batteries for
renewable energy storage - General requirements and methods of test - Part 1: Photovoltaic
off-grid application".
The electrical system shall comply with IEC 61439 (all parts) "Low-voltage switchgear and
controlgear assemblies".
The electrical system shall comply with IEC 61442 "Test methods for accessories for power
cables with rated voltages from 6 kV (Um = 7,2 kV) up to 30 kV (Um = 36 kV)".
The electrical system shall comply with IEC 61508 (all parts) "Functional safety of
electrical/electronic/programmable electronic safety-related systems".
The electrical system shall comply with IEC 61511-1 "Functional safety – Safety instrumented
systems for the process industry sector – Part 1: Framework, definitions, system, hardware
and application programming requirements".
The electrical system shall comply with IEC 61537 "Cable management – Cable tray systems
and cable ladder systems".
The electrical system shall comply with IEC 61558 (all parts) "Safety of transformers, reactors,
power supply units and combinations thereof".
The electrical system shall comply with IEC TR 61641 "Enclosed low-voltage switchgear and
controlgear assemblies – Guide for testing under conditions of arcing due to internal fault".
The electrical system shall comply with IEC 61643 (all parts) "Low-voltage surge protective
devices".
The electrical system shall comply with IEC 61660 (all parts) "Short-circuit currents in d.c.
auxiliary installations in power plants and substations".
The electrical system shall comply with IEC 60688 "Electrical measuring transducers for
converting A.C. and D.C. electrical quantities to analogue or digital signals".
The electrical system shall comply with IEC 61701 "Photovoltaic (PV) module – Salt mist
corrosion testing".
The electrical system shall comply with IEC 61730 (all parts) "Photovoltaic (PV) module safety
qualification".
The electrical system shall comply with IEC 60751 "Industrial platinum resistance
thermometers and platinum temperature sensors".
The electrical system shall comply with IEC 61800 (all parts) "Adjustable speed electrical
power drive systems".
ENGINEERING COMPANY STANDARD
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The electrical system shall comply with IEC 61810 (all parts) "Electromechanical elementary
relays".
The electrical system shall comply with IEC TS 61836 "Solar photovoltaic energy systems –
Terms, definitions and symbols".
The electrical system shall comply with IEC 61850 (all parts) "Communication networks and
systems for power utility automation".
The electrical system shall comply with IEC 61853 (all parts) "Photovoltaic (PV) module
performance testing and energy rating".
The electrical system shall comply with IEC 61869 (all parts) "Instrument transformers".
The electrical system shall comply with IEC 61892 (all parts) "Mobile and fixed offshore units –
Electrical installations".
The electrical system shall comply with IEC/TR 61912-1 and 2 "Low-voltage switchgear and
controlgear – Overcurrent protective devices".
The electrical system shall comply with IEC 61936-1 "Power installations exceeding 1 kV a.c. –
Part 1: Common rules".
The electrical system shall comply with IEC 62040 (all parts) "Uninterruptible power systems
(UPS)".
The electrical system shall comply with IEC 62041 "Transformers, power supplies, reactors and
similar products – EMC requirements".
The electrical system shall comply with IEC 62108 "Concentrator photovoltaic (CPV) modules
and assemblies – Design qualification and type approval".
The electrical system shall comply with IEC 62109 (all parts) "Safety of power converters for
use in photovoltaic power systems".
The electrical system shall comply with IEC 62124 "Photovoltaic (PV) stand-alone systems Design verification".
The electrical system shall comply with IEC 62231 "Composite station post insulators for
substations with a.c. voltages greater than 1 000 V up to 245 kV – Definitions, test methods
and acceptance criteria".
The electrical system shall comply with IEC 62262 "Degrees of protection provided by
enclosures for electrical equipment against external mechanical impacts (IK code)".
The electrical system shall comply with IEC 62271 (all parts) "High-voltage switchgear and
controlgear".
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
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The electrical system shall comply with IEC 62395-1 "Electrical resistance trace heating
systems for industrial and commercial applications – Part 1: General and testing
requirements".
The electrical system shall comply with IEC 62395-2 "Electrical resistance trace heating
systems for industrial and commercial applications – Part 2: Application guide for system
design, installation and maintenance".
The electrical system shall comply with IEC 62477-1 "Safety requirements for power electronic
converter systems and equipment – Part 1: General".
The electrical system shall comply with IEC 62477-2 “Safety requirements for power electronic
converter systems and equipment – Part 2: Power electronic converters from 1 000 V AC or 1
500 V DC up to 36 kV AC or 54 kV DC”.
The electrical system shall comply with IEC 62688 "Concentrator photovoltaic (CPV) modules
and assemblies – Safety qualification".
The electrical system shall comply with IEC TR 62778:2014 "Application of IEC 62471 for the
assessment of blue light hazard to light sources and luminaires".
The electrical system shall comply with IEC 62817 "Photovoltaic systems – Design qualification
of solar trackers".
The electrical system shall comply with IEC 62305 (all parts) "Protection against lightning".
The electrical system shall comply with IEC 62439 (all parts) "Industrial communication
networks - High availability automation networks".
The electrical system shall comply with IEC 62443 (all parts) "Industrial communication
networks – Network and system security".
The electrical system shall comply with IEC 62444 "Cable glands for electrical installations".
The electrical system shall comply with IEC 62471 "Photobiological safety of lamps and lamp
systems".
The electrical system shall comply with IEC 62485-1 "Safety requirements for secondary
batteries and battery installations – Part 1: General safety information".
The electrical system shall comply with IEC 62485-2 "Safety requirements for secondary
batteries and battery installations – Part 2: Stationary batteries".
The electrical system shall comply with IEC 62509 "Battery charge controllers for photovoltaic
systems – Performance and functioning".
The electrical system shall comply with IEC 62548 "Photovoltaic (PV) arrays – Design
requirements".
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
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The electrical system shall comply with IEC 62790 "Junction boxes for photovoltaic modules –
Safety requirements and tests".
The electrical system shall comply with IEC 62894 "Photovoltaic inverters – Data sheet and
name plate".
The electrical system shall comply with IEC 62920 "Photovoltaic power generating systems EMC requirements and test methods for power conversion equipment".
The electrical system shall comply with IEC 62930 "Electrical cables for photovoltaic systems
with a voltage rating of 1,5 kV DC".
The electrical system shall comply with IEC 62979 "Photovoltaic modules – Bypass diode –
Thermal runaway test".
The electrical system shall comply with IEC 62984 (all parts) “High-temperature secondary
batteries”.
The electrical system shall comply with IEC 63026 "Submarine power cables with extruded
insulation and their accessories for rated voltages from 6 kV (Um = 7,2 kV) up to 60 kV (Um =
72,5 kV) – Test methods and requirements".
The electrical system shall comply with IEC TR 63227 "Lightning and surge voltage protection
for photovoltaic (PV) power supply systems".
The electrical system shall comply with IEC TR 63228 "Measurement protocols for photovoltaic
devices based on organic, dye-sensitized or perovskite materials".
The electrical system shall comply with IEC 80000-6 "Quantities and units – Part 6:
Electromagnetism".
The electrical system shall comply with EN 1838 "Lighting applications - Emergency lighting".
The electrical system shall comply with EN 12464-1 "Light and lighting — Lighting of work
places - Part 1: Indoor work places".
The electrical system shall comply with EN 12464-2 "Light and lighting — Lighting of work
places - Part 2: Outdoor work places".
The electrical system shall comply with EN 50341-1 "Overhead electrical lines exceeding AC 1
kV - Part 1: General requirements - Common specifications".
The electrical system shall comply with EN 50522 "Earthing of power installations exceeding 1
kV a.c.".
The electrical system shall comply with EN 55011 "Industrial, scientific and medical equipment
- Radio-frequency disturbance characteristics - Limits and methods of measurement".
ENGINEERING COMPANY STANDARD
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The electrical system shall comply with ISO 80000 (all parts) "Quantities and units".
The electrical system shall comply with ISO 8528-1 "Reciprocating internal combustion engine
driven alternating current generating sets — Part 1: Application, ratings and performance".
The electrical system shall comply with ISO 8528-5 "Reciprocating internal combustion engine
driven alternating current generating sets — Part 5: Generating sets".
The electrical system shall comply with CAP 437 "Standards for offshore helicopter landing
areas".
The electrical system shall comply with IALA O-139 "The Marking of Man-Made Offshore
Structures".
The electrical system shall comply with IOGP S-620 "Supplementary Specification to IEC 62271200 High-voltage Switchgear and Controlgear".
The electrical system shall comply with IOGP S-560 "Supplementary Specification to IEC 614391 & 2 Low-voltage Switchgear and Controlgear Assemblies".
The electrical system shall comply with IOGP S-701 "Supplementary Specification to IEC
62040-3 AC Uninterruptible Power Systems (UPS)".
The electrical system shall comply with IOGP S-702 "Supplementary Specification to IEC
62040-5-3 DC Uninterruptible Power Systems (UPS)".
The electrical system shall comply with IOGP S-703 "Supplementary Specification to IEC
60034-1 Low Voltage Three Phase Cage Induction Motors".
The electrical system shall comply with IOGP S-704 "Supplementary Specification to IEC
60034-1 High Voltage Three Phase Cage Induction Motors".
The electrical system shall comply with IOGP S-720 "Supplementary Specification to IEC
60076-1 Transformers".
The electrical system shall comply with IOGP S-723 "Specification for Electric Process Heaters".
The electrical system shall comply with IOGP S-736 "Supplementary Specification to IEC
61800-2 Low-voltage AC Drives".
The electrical system shall comply with IOGP S-740 "Specification for Batteries".
The electrical system shall comply with IOGP S-747 "Supplementary Specification to IEC
61800-2 High-voltage AC Drive Systems".
The electrical system shall comply with IOGP S-620Q "Quality Requirements for High-voltage
Switchgear and Controlgear".
ENGINEERING COMPANY STANDARD
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The electrical system shall comply with IOGP S-560Q “Quality Requirements for Low-voltage
Switchgear and Controlgear Assemblies”.
The electrical system shall comply with IOGP S-701Q "Quality Requirements for AC
Uninterruptible Power Systems (UPS) (IEC 62040-3)".
The electrical system shall comply with IOGP S-702Q "Quality Requirements for DC
Uninterruptible Power Systems (UPS) (IEC 62040-5-3)".
The electrical system shall comply with IOGP S-703Q "Quality Requirements for Low Voltage
Three Phase Cage Induction Motors".
The electrical system shall comply with IOGP S-704Q "Quality Requirements for High Voltage
Three-phase Cage Induction Motors (IEC)".
The electrical system shall comply with IOGP S-720Q "Quality Requirements for Transformers".
The electrical system shall comply with IOGP S-723Q "Quality Requirements for Electric
Process Heaters".
The electrical system shall comply with IOGP S-736Q "Quality Requirements for Low-voltage
AC Drives (IEC)".
The electrical system shall comply with IOGP S-740Q "Quality Requirements for Batteries
(IEC)".
The electrical system shall comply with IOGP S-747Q "Quality Requirements for High-voltage
AC Drive Systems (IEC)".
For offshore facilities outside EU, the electrical system shall comply with IEC 60092-350
“Electrical installations in ships – Part 350: General construction and test methods of power,
control and instrumentation cables for shipboard and offshore applications”.
For offshore facilities outside EU, the electrical system shall comply with IEC 60092-353
“Electrical installations in ships – Part 353: Power cables for rated voltages 1 kV and 3 kV”
For offshore facilities outside EU, the electrical system shall comply with IEC 60092-354
“Electrical installations in ships – Part 354: Single- and three-core power cables with extruded
solid insulation for rated voltages 6 kV (Um = 7,2 kV) up to 30 kV (Um = 36 kV)”
For offshore facilities outside EU, the electrical system shall comply with IEC 60092-360
“Electrical installations in ships – Part 360: Insulating and sheathing materials for shipboard
and offshore units, power, control, instrumentation and telecommunication cables”.
For offshore facilities outside EU, the electrical system shall comply with IEC 60092-376
“Electrical installations in ships – Part 376: Cables for control and instrumentation circuits
150/250 V (300 V)”.
ENGINEERING COMPANY STANDARD
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For onshore facilities outside EU, the electrical system shall comply with IEC 60502-1 “Power
cables with extruded insulation and their accessories for rated voltages from 1 kV (Um = 1,2
kV) up to 30 kV (Um = 36 kV) – Part 1: Cables for rated voltages of 1 kV (Um = 1,2 kV) and 3
kV (Um = 3,6 kV)”.
For onshore facilities outside EU, the electrical system shall comply with IEC 60502-2 “Power
cables with extruded insulation and their accessories for rated voltages from 1 kV (Um = 1,2
kV) up to 30 kV (Um = 36 kV) – Part 2: Cables for rated voltages from 6 kV (Um = 7,2 kV) up
to 30 kV (Um = 36 kV)”.
For onshore facilities outside EU, the electrical system shall comply with IEC 60502-4 “Power
cables with extruded insulation and their accessories for rated voltages from 1 kV (Um = 1,2
kV) up to 30 kV (Um = 36 kV) – Part 4: Test requirements on accessories for cables with rated
voltages from 6 kV (Um = 7,2 kV) up to 30 kV (Um = 36 kV)”.
For onshore facilities outside EU, the electrical system shall comply with IEC 60840 “Power
cables with extruded insulation and their accessories for rated voltages above 30 kV (Um = 36
kV) up to 150 kV (Um = 170 kV) – Test methods and requirements”.
For facilities outside Italy, the electrical system shall comply with IEC 60364 (all parts) “Lowvoltage electrical installations”.
The electrical system shall comply IEEE Std C37.2™ “IEEE Standard for Electrical Power
System Device Function Numbers, Acronyms, and Contact Designations”, only as regards the
designation of the protection functions.
The electrical system shall comply with UL 94 “Standard for safety - Tests for Flammability of
Plastic Materials for Parts in Devices and Appliances”, for the equipment for which it is required
in the present document or in referenced standards.
The electrical system shall comply with IEEE Std C57.32™-2015 “IEEE Standard for
Requirements, Terminology, and Test Procedures for Neutral Grounding Devices”, only for the
equipment for which it is required in the present document.
The electrical system shall comply with IEEE Std C57.32a™-2020
IEEE Standard for
Requirements, Terminology, and Test Procedure for Neutral Grounding Devices - Amendment
1: Neutral Grounding Resistors Clause (AM)”, only for the equipment for which it is required in
the present document.
The electrical system shall comply with IEEE Std 519™ “IEEE Standard for Harmonic Control in
Electric Power Systems”, only in the cases specified in the present document or in referenced
standards.
1.2.1.3 Additional requirements for facilities in Italy
For facilities in Italy, if there is a “CEI EN” standard with the same number as the
corresponding IEC standard, the “CEI EN” standard shall be applied in lieu of the IEC one (e.g.
CEI EN 61439 in lieu of IEC 61439).
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For facilities in Italy, if there is a CEI standard that replaces an IEC standard, identical or with
modifications, the CEI standard shall be applied (e.g. CEI 64-8 in lieu of IEC 60364).
For facilities in Italy, the electrical system shall comply with CEI 0-2 “Guida per la definizione
della documentazione di progetto degli impianti elettrici”.
For facilities in Italy, the electrical system shall comply with CEI 0-5 "Dichiarazione CE di
conformità - Guida all’applicazione delle Direttive Nuovo Approccio e della Direttiva Bassa
Tensione (Memorandum CENELEC N 3)".
For facilities in Italy, the electrical system shall comply with CEI 0-14 "Guida all'applicazione
del DPR 462/01 relativo alla semplificazione del procedimento per la denuncia di installazioni e
dispositivi di protezione contro le scariche atmosferiche, di dispositivi di messa a terra degli
impianti elettrici e di impianti elettrici pericolosi".
For facilities in Italy, the electrical system shall comply with CEI 0-16 "Regola tecnica di
riferimento per la connessione di Utenti attivi e passivi alle reti AT e MT delle imprese
distributrici di energia elettrica".
For facilities in Italy, the electrical system shall comply with CEI 0-21 "Regola tecnica di
riferimento per la connessione di Utenti attivi e passivi alle reti BT delle imprese distributrici di
energia elettrica".
For facilities in Italy, the electrical system shall comply with CEI 16-6 "Codice di designazione
dei colori".
For facilities in Italy, the electrical system shall comply with CEI 16-7 "Elementi per identificare
i morsetti e la terminazione dei cavi".
For facilities in Italy, the electrical system shall comply with CEI 20-13 "Cavi per energia isolati
con mescola elastomerica con e senza particolari caratteristiche di reazione al fuoco rispondenti
al Regolamento Prodotti da Costruzione (CPR) - Tensioni nominali da U0/U 0,6/1 a U0/U 18/30
kV in c.a.".
For facilities in Italy, the electrical system shall comply with CEI 20-38 " Cavi per energia a basso
sviluppo di fumi opachi e gas acidi isolati con mescola elastomerica con particolari caratteristiche
di reazione al fuoco e rispondenti al Regolamento Prodotti da Costruzione (CPR) con tensioni
nominali U0/U non superiori a 0,6/1 kV in c.a.".
For facilities in Italy, the electrical system shall comply with CEI 20-45 "Cavi per energia isolati
in gomma elastomerica ad alto modulo di qualità G18, sotto guaina termoplastica o
elastomerica, con particolari caratteristiche di reazione al fuoco rispondenti al Regolamento
Prodotti da Costruzione (CPR) - Cavi con caratteristiche aggiuntive di resistenza al fuoco.
Tensione nominale U0/U: 0,6/1 kV".
For facilities in Italy, the electrical system shall comply with CEI 20-65 "Cavi elettrici isolati con
materiale elastomerico, termoplastico e isolante minerale per tensioni nominali non superiori a
ENGINEERING COMPANY STANDARD
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1000 V in corrente alternata e 1500 V in corrente continua - Metodi di verifica termica
(portata) per cavi raggruppati in fascio contenente conduttori di sezione differente".
For facilities in Italy, the electrical system shall comply with CEI 20-66 "Power cables with
extruded insulation and their accessories for rated voltages above 36 kV (Um = 42 kV) up to
150 kV (Um = 170 kV)".
For facilities in Italy, the electrical system shall comply with CEI 20-67 "Guida per l’uso dei cavi
0,6/1 kV".
For facilities in Italy, the electrical system shall comply with CEI 37-11 "Limitatori di
sovratensioni di bassa tensione - Parte 12: Limitatori di sovratensioni connessi a sistemi di
bassa tensione – Scelta e principi di applicazione".
For facilities in Italy, the electrical system shall comply with CEI 64-8 (all parts) "Impianti
elettrici utilizzatori a tensione nominale non superiore a 1 000 V in corrente alternata e a 1 500
V in corrente continua".
For facilities in Italy, the electrical system shall comply with CEI 81-27 "Guida d'applicazione
all'utilizzo di limitatori di sovratensioni all'arrivo della linea di alimentazione degli impianti
elettrici utilizzatori di bassa tensione".
For facilities in Italy, the electrical system shall comply with CEI 81-28 "Guida alla protezione
contro i fulmini degli impianti fotovoltaici".
For facilities in Italy, the electrical system shall comply with CEI 99-4 "Guida per l’esecuzione
di cabine elettriche MT/BT del cliente/utente finale".
For facilities in Italy, the electrical system shall comply with CEI 99-5 "Guida per l’esecuzione
degli impianti di terra delle utenze attive e passive connesse ai sistemi di distribuzione con
tensione superiore a 1 kV in c.a.".
For facilities in Italy, the electrical system shall comply with CEI 301-1 "Azionamenti elettrici Dizionario".
For facilities in Italy, the electrical system shall comply with CEI 301-3 "Guida per la
caratterizzazione ed identificazione degli azionamenti elettrici a velocità variabile per mezzo
della targa".
For facilities in Italy, the electrical system shall comply with CEI EN 50200 "Method of test for
resistance to fire of unprotected small cables for use in emergency circuits".
For facilities in Italy, the electrical system shall comply with CEI EN 50209 "Test of insulation
of bars and coils of high-voltage machines".
For facilities in Italy, the electrical system shall comply with CEI EN 50216 (all parts) "Power
transformers and reactor fittings".
ENGINEERING COMPANY STANDARD
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For facilities in Italy, the electrical system shall comply with CEI EN 50336 "Bushings for
transformers and reactor cable boxes not exceeding 36 kV".
For facilities in Italy, the electrical system shall comply with CEI EN 50341-2-13 "Linee
elettriche aeree con tensione superiore a 1 kV in c.a. - Parte 2-13: Aspetti Normativi Nazionali
(NNA) per l'Italia (basati sulla EN 50341-1:2012)".
For facilities in Italy, the electrical system shall comply with CEI EN 50341-3 "Overhead
electrical lines exceeding AC 45 kV Part 3: Set of National Normative Aspects".
For facilities in Italy, the electrical system shall comply with CEI EN 50347 "General purpose
three-phase induction motors having standard dimensions and outputs - Frame numbers 56 to
315 and flange numbers 65 to 740".
For facilities in Italy, the electrical system shall comply with CEI EN 50380 "Marking and
documentation requirements for Photovoltaic Modules".
For facilities in Italy, the electrical system shall comply with CEI EN 50399 "Common test
methods for cables under fire conditions - Heat release and smoke production measurement on
cables during flame spread test – Test apparatus, procedures, results".
For facilities in Italy, the electrical system shall comply with CEI EN 50461 "Solar cells Datasheet information and product data for crystalline silicon solar cells".
For facilities in Italy, the electrical system shall comply with CEI EN 50524 "Data sheet for
photovoltaic inverters".
For facilities in Italy, the electrical system shall comply with CEI EN 50588 (all parts) "Medium
power transformers 50 Hz, with highest voltage for equipment not exceeding 36 kV".
For facilities in Italy, the electrical system shall comply with CEI EN 50575 "Cavi per energia,
controllo e comunicazioni – Cavi per applicazioni generali nei lavori di costruzione soggetti a
prescrizione di resistenza all’incendio".
For facilities in Italy, the electrical system shall comply with CEI EN 50708 (all parts) "Power
transformers - Additional European requirements".
For facilities in Italy, the electrical system shall comply with CEI EN 61194 "Characteristic
parameters of stand-alone photovoltaic (PV) systems".
For facilities in Italy, the electrical system shall comply with CEI-UNEL 00721 "Colori di guaina
dei cavi elettrici".
For facilities in Italy, the electrical system shall comply with CEI-UNEL 00722 "Identificazione
delle anime dei cavi".
For facilities in Italy, the electrical system shall comply with CEI-UNEL 35011 "Cavi per energia
e segnalamento - Sigle di designazione".
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For facilities in Italy, the electrical system shall comply with CEI-UNEL 35016 "Classe di
Reazione al fuoco dei cavi in relazione al Regolamento EU "Prodotti da Costruzione"
(305/2011)".
For facilities in Italy, the electrical system shall comply with CEI-UNEL 35024 "Cavi elettrici
isolati con materiale elastomerico o termoplastico per tensioni nominali non superiori a 1000 V
in corrente alternata e a 1500 V in corrente continua - Portate di corrente in regime
permanente per posa in aria".
For facilities in Italy, the electrical system shall comply with CEI-UNEL 35026 "Cavi elettrici
isolati con materiale elastomerico o termoplastico per tensioni nominali di 1000 V in corrente
alternata e 1500 V in corrente continua - Portate di corrente in regime permanente per posa
interrata".
For facilities in Italy, the electrical system shall comply with CEI-UNEL 35312 "Cavi per energia
isolati in gomma elastomerica di qualità G18, sotto guaina termoplastica o elastomerica, con
particolari caratteristiche di reazione al fuoco e rispondenti al Regolamento Prodotti da
Costruzione (CPR) - Cavi con conduttori flessibili per posa fissa - Tensione nominale Uo/U
0,6/1kV - Classe di reazione al fuoco: B2ca-s1a,d1,a1".
For facilities in Italy, the electrical system shall comply with CEI-UNEL 35324 "Cavi per energia
isolati in gomma etilenpropilenica, ad alto modulo di qualità G16 sotto guaina termoplastica di
qualità M16, con particolari caratteristiche di reazione al fuoco e rispondenti al Regolamento
Prodotti da Costruzione (CPR) - Cavi unipolari e multipolari con conduttori flessibili per posa
fissa con o senza schermo (treccia o nastro) - Tensione nominale Uo/U 0,6/1kV - Classe di
reazione al fuoco: Cca-s1b,d1,a1".
For facilities in Italy, the electrical system shall comply with UNI EN 13501-6 "Fire classification
of construction products and building elements - Part 6: Classification using data from reaction
to fire tests on power, control and communication cables".
For facilities in Italy, CEI 64-8 shall replace IEC 60364.
For facilities in Italy, CEI 20-66 shall replace IEC 60840.
For facilities in Italy, CEI 37-11 shall replace IEC 61643-12.
1.2.1.4 Additional requirements for facilities in CENELEC countries
For facilities in countries that are members of CENELEC, if there is a “EN” or “HD” standard
with the same number as the corresponding IEC standard, it shall be applied in lieu of the IEC
one (e.g. EN 61439 in lieu of IEC 61439).
For facilities in countries that are members of CENELEC, if there is a “EN” standard that
replaces an IEC standard, identical or with modifications, the EN standard shall be applied.
For facilities in countries that are members of CENELEC, the electrical system shall comply with
EN 13501-6 “Fire classification of construction products and building elements - Part 6:
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Classification using data from reaction to fire tests on power, control and communication
cables”.
For facilities in countries that are members of CENELEC, the electrical system shall comply with
EN 50200 "Method of test for resistance to fire of unprotected small cables for use in
emergency circuits".
For facilities in countries that are members of CENELEC, the electrical system shall comply with
EN 50209 "Test of insulation of bars and coils of high-voltage machines".
For facilities in countries that are members of CENELEC, the electrical system shall comply with
EN 50216 (all parts) "Power transformers and reactor fittings".
For facilities in countries that are members of CENELEC, the electrical system shall comply with
EN 50336 "Bushings for transformers and reactor cable boxes not exceeding 36 kV".
For facilities in countries that are members of CENELEC, the electrical system shall comply with
EN 50341-2 (all parts) "Overhead electrical lines exceeding AC 1 kV - National Normative
Aspects (NNA)".
For facilities in countries that are members of CENELEC, the electrical system shall comply with
EN 50341-3 "Overhead electrical lines exceeding AC 45 kV Part 3: Set of National Normative
Aspects".
For facilities in countries that are members of CENELEC, the electrical system shall comply with
EN 50347 "General purpose three-phase induction motors having standard dimensions and
outputs - Frame numbers 56 to 315 and flange numbers 65 to 740".
For facilities in countries that are members of CENELEC, the electrical system shall comply with
EN 50380 "Marking and documentation requirements for Photovoltaic Modules".
For facilities in countries that are members of CENELEC, the electrical system shall comply with
EN 50399 "Common test methods for cables under fire conditions - Heat release and smoke
production measurement on cables during flame spread test – Test apparatus, procedures,
results".
For facilities in countries that are members of CENELEC, the electrical system shall comply with
EN 50461 "Solar cells - Datasheet information and product data for crystalline silicon solar
cells".
For facilities in countries that are members of CENELEC, the electrical system shall comply with
EN 50524 "Data sheet for photovoltaic inverters".
For facilities in countries that are members of CENELEC, the electrical system shall comply with
EN 50588 (all parts) "Medium power transformers 50 Hz, with highest voltage for equipment
not exceeding 36 kV".
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For facilities in countries that are members of CENELEC, the electrical system shall comply with
EN 50575 "Power, control and communication cables - Cables for general applications in
construction works subject to reaction to fire requirements".
For facilities in countries that are members of CENELEC, the electrical system shall comply with
EN 50708 (all parts) "Power transformers - Additional European requirements".
For facilities in countries that are members of CENELEC, the electrical system shall comply with
EN 61194 "Characteristic parameters of stand-alone photovoltaic (PV) systems".
1.2.2
Laws, Decrees, Directives
Laws, Decrees and Directives, issued by local Entities and Authorities under which equipment
shall be installed, shall be applied.
The Regulation 305/2011 of the European Parliament and of the Council (“REGULATION (EU)
No 305/2011 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 9 March 2011 laying
down harmonised conditions for the marketing of construction products and repealing Council
Directive 89/106/EEC”) and its interpretation through National Laws and Committee shall be
complied with for cables installed in EU.
The Directive 2013/35/EU of the European Parliament and of the Council (“DIRECTIVE
2013/35/EU OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 26 June 2013 on the
minimum health and safety requirements regarding the exposure of workers to the risks
arising from physical agents (electromagnetic fields) (20th individual Directive within the
meaning of Article 16(1) of Directive 89/391/EEC) and repealing Directive 2004/40/EC”) shall
also be applicable outside EU, in the cases indicated in the present document.
1.2.3
Internal standardization references
1.2.3.1 COMPANY Standards
The electrical system shall comply with COMPANY Standard 20056.ENG.ELE.STD “Explosionproof connection box with contactor for shedding”.
The electrical system shall comply with COMPANY Standard 02947.ENG.ELE.STD
“Measurement of earth electrical resistivity”.
The electrical system shall comply with COMPANY Standard 20231.ENG.ELE.PRG “Minimum
technical content of documents for each project development phase”.
The electrical system shall comply with COMPANY Standard 20168.ENG.ELE.STD “Synchronous
electric machines”.
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The electrical system shall comply with COMPANY Standard 28881.ENG.ELE.STD “M.V.
switchgear and controlgear (over 1000V a.c. and up 52kV a.c.) - typical incoming / outgoing
feeders”.
The electrical system shall comply with COMPANY Standard 28880.ENG.ELE.STD “L.V.
switchgear and controlgear assemblies (up to 1000 V a.c 1500 V d.c) – typical incoming /
outgoing feeders”.
The electrical system shall comply with COMPANY Standard 20174.ENG.ELE.STD “Aids to
navigation & helideck lighting system for offshore platforms and floaters".
The electrical system shall comply with COMPANY Standard 28882.ENG.ELE.STD “AC
uninterruptible power supply system - typical configurations”.
The electrical system shall comply with COMPANY Standard 28914.ENG.ELE.STD “Luminaires”.
The electrical system shall comply with COMPANY Standard 28915.ENG.ELE.STD “Electrical
bulk material”.
The electrical system shall comply with COMPANY Standard 28916.ENG.ELE.STD “Cable
ladders and cable trays”.
The electrical system shall comply with COMPANY Standard 28917.ENG.ELE.STD “Floodlight
high masts”.
The electrical system shall comply with COMPANY Standard 20180.ENG.ELE.STD “Electrical
Management System (EMS)”.
The electrical system shall comply with COMPANY standard 20183.VAR.GEN.STD “Units of
measurement”, where referenced in the present document.
The electrical system shall comply with COMPANY standard 20198.VAR.LCI.STD “Item
numbering”, where referenced in the present document.
The electrical system shall comply with COMPANY standard 20452.ENG.MEC.PRG “Guideline for
HVAC systems for offshore / FPSO production installations”, where referenced in the present
document.
The electrical system shall comply with COMPANY standard 20453.ENG.MEC.PRG “Guideline for
HVAC systems for onshore production installations”, where referenced in the present
document.
The electrical system shall comply with COMPANY standard 28037.ENG.STA.STD
“Instrumentation & automation included in package plants”, where referenced in the present
document.
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 34 of 135
The electrical system shall comply with COMPANY standard 20531.ENG.STA.STD “Measure,
control, data processing and similar associated electronic system protection subject to indirect
lightning”, where referenced in the present document.
The electrical system shall comply with COMPANY standard 20532.ENG.STA.STD “Earthing
systems for instrumentation plants”, where referenced in the present document.
The electrical system shall comply with COMPANY standard 21000.ENG.PRC.STD “Plant graphic
symbology”, where referenced in the present document.
The electrical system shall comply with COMPANY standard 28045.ENG.STA.PRG “Minimum
design requirements for instrumentation and control systems”, where referenced in the
present document.
The electrical system shall comply with COMPANY standard 29000.ENG.CPI.STD “Paintings and
coatings for offshore and coastal structures”, where referenced in the present document.
The electrical system shall comply with COMPANY standard 29001.ENG.CPI.STD “Paintings and
coatings for onshore facilities”, where referenced in the present document.
The electrical system shall comply with COMPANY document opi hse 023 eni spa “Safety &
Environmental Minimum Design Requirements”, where referenced in the present document.
1.2.3.2 COMPANY forms
The COMPANY form MOD.ELE.RMA.022 “Data sheet for low voltage three phase cage induction
motors (IOGP S-703D) (TDS)” shall be utilized.
The COMPANY form MOD.ELE.RMA.023 “Quality requirements for low voltage three phase cage
induction motors (IOGP S-703Q) (IDS)” shall be utilized.
The COMPANY form MOD.ELE.RMA.024 “Information requirements for low voltage three phase
cage induction motors (IOGP S-703L) (DDS)” shall be utilized.
The COMPANY form MOD.ELE.NAV.001 “Aids to navigation & helideck lighting system for
offshore platforms and floaters (TDS)” shall be utilized.
The COMPANY form MOD.ELE.NAV.002 “Aids to navigation & helideck lighting system for
offshore platforms and floaters (IDS)” shall be utilized.
The COMPANY form MOD.ELE.NAV.003 “Aids to navigation & helideck lighting system for
offshore platforms and floaters (DDS)” shall be utilized.
The COMPANY form MOD.ELE.NAV.009 “Temporary navigation aids system (TDS)” shall be
utilized.
The COMPANY form MOD.ELE.NAV.010 “Temporary navigation aids system (IDS)” shall be
utilized.
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 35 of 135
The COMPANY form MOD.ELE.NAV.011 “Temporary navigation aids system (DDS)” shall be
utilized.
The COMPANY form MOD.ELE.MVS.001 “Procurement Data Sheet for High-voltage Switchgear
and Controlgear (including IOGP S-620D) (TDS)” shall be utilized.
The COMPANY form MOD.ELE.MVS.002 “Quality Requirements for High-voltage Switchgear and
Controlgear (IOGP S-620Q) (IDS)” shall be utilized.
The COMPANY form MOD.ELE.MVS.003 “Information Requirements for High-voltage Switchgear
and Controlgear (IOGP S-620L) (DDS)” shall be utilized.
The COMPANY form MOD.ELE.LVS.001 “Procurement Data Sheet for Low-voltage Switchgear and
Controlgear (including IOGP S-560D) (TDS)” shall be utilized.
The COMPANY form MOD.ELE.LVS.002 “Quality Requirements for Low-voltage Switchgear and
Controlgear Assemblies (IOGP S-560Q) (IDS)” shall be utilized.
The COMPANY form MOD.ELE.LVS.003 “Information Requirements for Low-voltage Switchgear
and Controlgear (IOGP S-560L) (DDS)” shall be utilized.
The COMPANY form MOD.ELE.ACB.001 “Data Sheet for Batteries (IEC) (IOGP S-740D) (TDS)”
shall be utilized.
The COMPANY form MOD.ELE.ACB.002 “Quality Requirements for Batteries (IEC) (IOGP S740Q) (IDS)” shall be utilized.
The COMPANY form MOD.ELE.ACB.003 “Information Requirements for Batteries (IEC) (IOGP S740L) (DDS)” shall be utilized.
The COMPANY form MOD.ELE.UPS.001 “Data Sheet for AC Uninterruptible Power Systems
(UPS) (IEC 62040-3) (IOGP S-701D) (TDS)” shall be utilized.
The COMPANY form MOD.ELE.UPS.002 “Quality Requirements for AC Uninterruptible Power
Systems (UPS) (IEC 62040-3) (IOGP S-701Q) (IDS)” shall be utilized.
The COMPANY form MOD.ELE.UPS.003 “Information Requirements for AC Uninterruptible
Power Systems (UPS) (IEC 62040-3) (IOGP S-701L) (DDS)” shall be utilized.
The COMPANY form MOD.ELE.UPS.005 “Data Sheet for DC Uninterruptible Power Systems
(UPS) (IEC 62040-5-3) (IOGP S-702D) (TDS)” shall be utilized.
The COMPANY form MOD.ELE.UPS.006 “Quality Requirements for DC Uninterruptible Power
Systems (UPS) (IEC 62040-5-3) (IOGP S-702Q) (IDS)” shall be utilized.
The COMPANY form MOD.ELE.UPS.007 “Information Requirements for DC Uninterruptible
Power Systems (UPS) (IEC 62040-5-3) (IOGP S-702L) (DDS)” shall be utilized.
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 36 of 135
The COMPANY form MOD.ELE.ESH.001 “High voltage substation - technical data sheet (TDS)”
shall be utilized.
The COMPANY form MOD.ELE.ESH.002 “High voltage substation - inspection data sheet (IDS)”
shall be utilized.
The COMPANY form MOD.ELE.ESH.003 “High voltage substations - required documentation
data sheet (DDS)” shall be utilized.
The COMPANY form MOD.ELE.TRA.001 “Data sheet for transformers (IOGP S-720D) (TDS)”
shall be utilized.
The COMPANY form MOD.ELE.TRA.002 “Quality requirements for transformers (IOGP S-720Q)
(IDS)” shall be utilized.
The COMPANY form MOD.ELE.TRA.004 “Information requirements for transformers (IOGP S720L) (DDS)” shall be utilized.
The COMPANY form MOD.ELE.RMA.002 “Data Sheet for High Voltage Three-phase Cage
Induction Motors (IEC) (IOGP S-704D) (TDS)” shall be utilized.
The COMPANY form MOD.ELE.RMA.003 “Quality Requirements for High Voltage Three-phase
Cage Induction Motors (IEC) (IOGP S-704Q) (IDS)” shall be utilized.
The COMPANY form MOD.ELE.RMA.005 “Information Requirements for High Voltage Threephase Cage Induction Motors (IEC) (IOGP S-704L) (DDS)” shall be utilized.
The COMPANY form MOD.ELE.RMA.007 “Synchronous motors - technical data sheet (TDS)”
shall be utilized.
The COMPANY form MOD.ELE.RMA.011 “Synchronous generators (TDS)” shall be utilized.
The COMPANY form MOD.ELE.RMA.012 “Synchronous generators (IDS)” shall be utilized.
The COMPANY form MOD.ELE.RMA.013 “Synchronous generators (DDS)” shall be utilized.
The COMPANY form MOD.ELE.RMA.015 “Procurement Data Sheet for High-voltage AC Drive
Systems (IEC) (IOGP S-747D) (TDS)” shall be utilized.
The COMPANY form MOD.ELE.RMA.016 “Quality Requirements for High-voltage AC Drive
Systems (IEC) (IOGP S-747Q) (IDS)” shall be utilized.
The COMPANY form MOD.ELE.RMA.017 “Information Requirements for High-voltage AC Drive
Systems (IEC) (IOGP S-747L) (DDS)” shall be utilized.
The COMPANY form MOD.ELE.RMA.019 “Procurement Data Sheet for Low-voltage AC Drives
(IEC) (IOGP S-736D) (TDS)” shall be utilized.
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 37 of 135
The COMPANY form MOD.ELE.RMA.020 ”Quality Requirements for Low-voltage AC Drives (IEC)
(IOGP S-736Q) (IDS)” shall be utilized.
The COMPANY form MOD.ELE.RMA.021 “Information Requirements for Low-voltage AC Drives
(IEC) (IOGP S-736L) (DDS)” shall be utilized.
The COMPANY form MOD.ELE.ETG.001 “Earthing resistors - technical data sheet (TDS)” shall
be utilized.
The COMPANY form MOD.ELE.ETG.002 “Resistors for earthing the neutral of electric systems inspection data sheet (IDS)” shall be utilized.
The COMPANY form MOD.ELE.ETG.003 “Earthing resistors - required documentation data sheet
(DDS)” shall be utilized.
The COMPANY form MOD.ELE.ESY.006 “Overhead transmission line from 11kV up to 66kV technical data sheet (TDS)” shall be utilized.
The COMPANY form MOD.ELE.ESY.007 “Overhead transmission line from 11kV up to 66kV inspection data sheet (IDS)” shall be utilized.
The COMPANY form MOD.ELE.ESY.008 “Overhead transmission line from 11kV up to 66kV required documentation data sheet (DDS)” shall be utilized.
The COMPANY form MOD.ELE.ESY.019 “Overhead transmission from 11 kV up to 45 kV - civil
work (TDS)” shall be utilized.
The COMPANY form MOD.ELE.ESY.021 “Overhead transmission from 11 kV up to 45 kV material data sheet (TDS)” shall be utilized.
The COMPANY form MOD.ELE.PKG.001 “Diesel generating set - technical data sheet (TDS)”
shall be utilized.
The COMPANY form MOD.ELE.PKG.002 “Internal combustion generation set - inspection data
sheet (IDS)” shall be utilized.
The COMPANY form MOD.ELE.PKG.003 “Internal combustion generation set - inspection data
sheet (IDS)” shall be utilized.
The COMPANY form MOD.ELE.PKG.201 “Diesel/gas generating set - required documentation
data sheet (DDS)” shall be utilized.
The COMPANY form MOD.ELE.ELN.001 “List analog and digital signals to system of
supervision/monitoring, control and protection of the electrical network (EMS) - I/O list” shall
be utilized.
The COMPANY form MOD.ELE.ESY.001 “Electrical load list - general data sheet (GDS)” shall be
utilized.
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 38 of 135
The COMPANY form MOD.ELE.EAM.001 “Electrical material list - list (LST)” shall be utilized.
The COMPANY form MOD.ELE.EAM.002 “Electrical equipment list” shall be utilized.
The COMPANY form MOD.ELE.CBL.001 “Electric cables - technical data sheet (TDS)” shall be
utilized.
The COMPANY form MOD.ELE.CBL.003 “Electric cables - required documentation data sheet
(DDS)” shall be utilized.
The COMPANY form MOD.ELE.CBL.010 “Submarine electric cable (TDS)” shall be utilized.
The COMPANY form MOD.ELE.CBL.012 “Competence submarine electrical cable - general data
sheet (GDS)” shall be utilized.
The COMPANY form MOD.ELE.CBL.013 “Submarine electric cable (DDS)” shall be utilized.
The COMPANY form MOD.ELE.CBL.020 “Electrical cable list - list (LST)” shall be utilized.
The COMPANY form MOD.ELE.CBL.030 “Electrical interconnecting list (LST)” shall be utilized.
The COMPANY form MOD.ELE.CBL.040 “Electrical system-summary of power circuits and
protection verification” shall be utilized.
The COMPANY form MOD.ELE.GEN.002 “Data sheet for measurement of soil electric resistivity”
shall be utilized.
The COMPANY form MOD.ELE.ESY.020 “Electrical load balance” shall be utilized.
The COMPANY form MOD.ELE.FMX.007 “Data Sheet for Electric Process Heaters (IOGP S-723D)
(TDS)” shall be utilized.
The COMPANY form MOD.ELE.FMX.008 “Quality Requirements for Electric Process Heaters
(IOGP S-723Q) (IDS)” shall be utilized.
The COMPANY form MOD.ELE.FMX.009 “Information Requirements for Electric Process Heaters
(IOGP S-723L) (DDS)” shall be utilized.
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
2
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 39 of 135
FUNCTIONAL REQUIREMENTS
2.1
DEFINITIONS
2.1.1
General definitions
Term
Description
COMPANY
The party that initiates the project and
ultimately pays for its design and
construction. The COMPANY will generally
specify technical requirements. The term
“COMPANY” may also include agents or
consultants authorised to act for, and on
behalf of, the COMPANY.
CONTRACTOR
Party that performs the design,
procurement, supply, manufacturing,
construction, testing and commissioning
activities (or some of them).
SUBCONTRACTOR
Any supplier, distributor, vendor, or firm
that furnishes supplies or services to or for a
prime contractor or another subcontractor.
SUPPLIER
Organization or person that provides a
product.
VENDOR
A supplier of material or services offered
from a catalogue or price list and purchased
by issue of a purchase order.
Shall
The word shall is used to indicate that a
provision is mandatory.
Should
The word should is used to indicate that a
provision is not mandatory, but
recommended as good practice.
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
2.1.2
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 40 of 135
Specific definitions
Term
Acronym
Description
Bulk material
Lighting system materials, earthing system
materials, motor control stations, power
sockets, convenience sockets, plugs,
conduits, cable passages, MCTs, cable trays,
cable ladders, cable glands, junction boxes,
electrical resistance trace heating cables.
Control/command cable
Cable used for transmission of information
and command with a voltage higher than 125
V AC or 125 V DC.
Electrical room
Room or space in a building or prefabricated
cabin dedicated to electrical switchgear and
UPS.
Electrical room building
Building or prefabricated cabin dedicated to
electrical equipment. Electrical room building
can contain electrical room, battery room,
transformer room, cable cellar, room used
for warehouse, archive and operator
workstation.
Instrument/automation
cable
Cable used for transmission of information or
command with a voltage level less than 125
V AC or 125 V DC.
Small power
Motors rated less than 1 kW, lighting users,
power sockets, convenience outlets, space
heaters.
Site conditions
The external factors (e.g. altitude, air
temperature, wind velocity, vibrations,
relative humidity, pollution) which might
influence the operation of an equipment.
Soft Starter
Semiconductor based device reducing the
inrush current during motor start-up by
means of reduced voltage and voltage rampup, without frequency control.
Low Voltage
LV
Voltage up to 1 kV AC or 1,5 kV DC.
Medium Voltage
MV
Voltage higher than 1 kV AC and up to 52 kV
AC. NOTE: even if international IEC/EN
standard define LV for levels up to 1 kV AC
and HV for levels over 1kV AC, for
compatibility within COMPANY documents the
differentiation between MV and HV is
maintained.
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 41 of 135
Term
Acronym
Description
High Voltage
HV
Voltage higher than 52 kV AC.
Motor Control Centre
MCC
Low voltage switchgear without incoming
functional units connected to generators or
transformers and with all outgoing functional
units in withdrawable execution.
Power Centre
PC
Low voltage switchgear without outgoing
functional units in withdrawable execution,
but with all outgoing functional units with
withdrawable circuit breaker.
Power Motor Control Centre
PMCC
Low voltage switchgear with outgoing
functional units both in withdrawable and
fixed execution, or with all outgoing
functional units in withdrawable execution
but with incoming functional units directly
connected to generators or transformers.
Auxiliary Service Panel
ASP
Low voltage switchgear feeding only small
power loads, or feeding other switchgear that
feed only small power loads. NOTE: by
definition, lighting circuits are considered
“small power”.
Lighting Panel
LP
Low voltage switchgear feeding only lighting
loads, or feeding other switchgear that feed
only lighting loads.
UPS distribution board
Low voltage switchgear directly fed from one
or more UPS units, located in the same
enclosure as the UPS or in a different one,
and feeding the loads of the UPS units.
HVAC switchgear
Low voltage switchgear dedicated to HVAC
loads and provided by HVAC SUPPLIER.
NOTE: the present document refers only to
power distribution part, for control of HVAC
refer to 28037.ENG.STA.STD.
Local Distribution Panel
Low voltage switchgear with rated current
lower than 250A and used to feed locally
small power, motor valves or electrical
tracing circuits.
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
2.2
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 42 of 135
SYMBOLS AND ABBREVIATIONS
Acronym / Abbr.
Description
AC
Alternating Current
ACB
Air Circuit Breaker
AFWF
Air Forced Water Forced
AGM
Absorbed Glass Mat
AIS
Air Insulated Switchgear
ASP
Auxiliary Service Panel
BDM
Basic Drive Module (see IEC 61800-2)
CDM
Complete Drive Module (see IEC 61800-2)
CAS
Conformity Assessment System
CENELEC
Comité Européen de Normalisation en Electronique et en
Electrotechnique
CE
Conformité Européenne
COP
continuous power
CT
Current Transformer
DC
Direct Current
DCS
Distributed Control System
DDS
Document Data Sheet
EMS
Electrical Management System
EPL
Equipment Protection Level (see IEC 60079-0)
EU
European Union
FCL
Fault Current limiter
FEED
Front End Engineering Design
FPSO
Floating Production Storage and Offloading
GIS
Gas Insulated Switchgear
GRP
Glass Reinforced Polyester
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 43 of 135
Acronym / Abbr.
Description
HV
High Voltage
HVAC
Heating, Ventilation, & Air Conditioning
ICSS
Integrated Control and Safety System
IDS
Inspection Data Sheet
IEC
International Electrotechnical Commission
IOGP
International Association of Oil & Gas Producers
IP
Ingress Protection degree
ISO
International Standards Organisation
IT
See IEC 60364-1 (onshore) and IEC 61892-2 (offshore)
LP
Lighting Panel
LPL
Lightning Protection Level (see IEC 62305-1)
LTP
limited-time running power
LV
Low Voltage
MCB
Miniature Circuit Breaker
MCC
Motor Control Centre
MCT
Multi-Cable Transits
MV
Medium Voltage
NER
Neutral Earthing Resistors
PC
Power Centre
PDS
Power Drive System (see IEC 61800-2)
PMCC
Power Motor Control Centre
PRP
prime power
PVC
Poly Vinyl Chloride
RCD
Residual Current Device
RICE
Reciprocating Internal Combustion Engine
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 44 of 135
Acronym / Abbr.
Description
RTD
Resistance Temperature Detector
SIS
Safety Instrumented System
SMC
Sodium Metal Chloride
SPD
Surge Protective Device
TDS
Technical Data Sheet
THD
Total Harmonic Distortion
TN
See IEC 60364-1 (onshore) and IEC 61892-2 (offshore)
TN-S
See IEC 60364-1 (onshore) and IEC 61892-2 (offshore)
TT
See IEC 60364-1
UCP
Unit Control Panel
UL
Underwriters Laboratories
UPS
Uninterruptible Power Supply
VRLA
Valve Regulated Lead Acid
VT
Voltage Transformer
2.3
GRAPHIC, SYMBOLS, CODES AND IDENTIFICATIONS TAG
Graphic symbols, codes and identification tags shall comply with COMPANY standard
21000.ENG.PRC.STD and with IEC 60617.
2.4
OPERATIVE ENVIRONMENT
Rating of equipment and systems shall comply with the range of ambient conditions (e.g.
temperature, humidity) indicated in relevant project documentation (e.g. Basis of Design).
Equipment that have to remain operational in case of partial or total shut down of HVAC shall
also be rated for the ambient conditions that can occur with such partial or total shutdown of
the HVAC.
2.5
MEASUREMENT UNITS
Measurement units shall comply with COMPANY Standard 20183.VAR.GEN.STD.
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 45 of 135
Measurement units shall comply with ISO 80000 series and IEC 80000-6.
2.6
DESIGN AND ENGINEERING PRINCIPLES
2.6.1
Protection against explosion and fire hazard
Electrical equipment for hazardous areas shall comply with IECEx System Directives or with
European ATEX Directive 2014/34/EU, depending on project requirements.
Certificates and tests for equipment and materials for use in hazardous areas shall comply with
IECEx System Directives or with European ATEX Directive 2014/34/EU, depending on project
requirements.
2.6.2
Certificates, declarations and test reports
VENDOR test reports shall be provided for electrical equipment, according to the inspection
data sheets and to the referenced standards.
For all electrical equipment and materials, the reports of all performed tests shall be provided.
2.7
ELECTRICAL SYSTEM DESIGN
2.7.1
Electrical loads classification and load balance
2.7.1.1 Loads classification
Loads shall be classified in normal, preferential and safety loads.
The loads not included in preferential or safety loads shall be classified as normal.
Preferential loads shall include users necessary for the restart of the main generation, to
prevent damage to plant equipment, to guarantee control of the whole plant, to provide
restoration of normal operating conditions, to maintain manned areas in habitable conditions.
In offshore facilities in which essential generators are present, preferential loads shall be
divided in essential and emergency loads.
In facilities in which essential generators are not present, emergency loads shall be considered
to have the same meaning as preferential loads.
In onshore plants, preferential loads shall be fed by main power source and, in case of its
unavailability, by the emergency power generation.
ENGINEERING COMPANY STANDARD
Documento riservato di proprietà di Eni SpA. Esso non sarà mostrato a terzi né utilizzato per scopi diversi da quelli per i quali è stato inviato.
This document is property of Eni SpA. It shall neither be shown to third parties nor used for purposes other than those for which it has been sent.
Eni SpA
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 46 of 135
Users necessary for life safeguarding, safety of personnel and security shall be classified as
safety loads.
Telecommunication equipment shall be classified as safety loads.
ICSS, EMS and other control systems shall be classified as safety loads.
Public address and general alarm systems shall be classified as safety loads.
Emergency escape lighting without incorporated battery shall be classified as safety loads.
Emergency escape lighting with incorporated battery shall be classified as emergency loads.
Helideck lights, aeronautical obstruction lights, aviation obstacle lights, boat landing status
lights and navigation aids equipment shall be classified as safety loads.
Electrical users necessary for the safe shut down of turbines shall be classified as safety loads.
Normal loads shall be fed by the main power source.
In offshore facilities without essential power generation, preferential loads shall be fed by main
power source and, in case of its unavailability, by the emergency power generation.
In offshore facilities with essential power generation, preferential loads shall be fed by main
power source and, in case of its unavailability, by the essential power generation.
In offshore facilities with essential power generation, emergency loads shall be fed by
emergency power generation in case of unavailability of both main power source and essential
generation.
In offshore facilities, the users listed in IEC 61892-2 Annex B shall be classified as emergency
loads, if not already classified as safety loads as per the indications of the present document.
In offshore facilities in which essential generators are present, the users listed in IEC 61892-2
Annex A shall be classified as essential loads, if not already classified as emergency or safety
loads as per the indication of the present document.
UPS units shall be classified as emergency loads.
Safety loads shall be fed by UPS with battery back-up.
2.7.1.2 Load balance
The total plant demand load shall be calculated.
The total demand load of each switchgear shall be calculated.
The total demand load shall be calculated for both active and reactive power.
ENGINEERING COMPANY STANDARD
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The total demand load shall be the sum of Continuous Load, Intermittent Load and % Standby Load.
The % Stand-by Load shall be the maximum among 10% of total stand-by loads, the biggest
single stand-by load and the total loads of the biggest stand-by unit (e.g. a compressor train
with auxiliaries).
The total plant demand load shall be calculated under the specified operating conditions
identified during the project development.
If multiple sockets are fed from the same feeder, a conventional load shall be applied,
calculated as the sum of the rated powers of the users, multiplied by a load factor not lower
than 1/n+0,1, where “n” is the number of the sockets.
If multiple users other than sockets are fed form the same feeder, no reduction shall be
applied with respect to the rated powers of the users.
In evaluation and selection project phases (pre-feasibility and feasibility), apart from already
planned future plant expansions, a contingency of 30% shall be applied to the total plant
demand load.
In definition project phase (Basic Design and FEED), apart from already planned future plant
expansions, a contingency of 20% shall be applied to the total plant demand load.
In execution phase, apart from already planned future plant expansions, a contingency of 10%
shall be applied to the total plant demand load, at the end of detailed engineering.
Contingency margins shall be applied in the whole range of environmental operating conditions
and in each operating scenario.
Power transformers shall be sized considering the total demand load of downstream
switchgear, plus contingency.
2.7.1.3 Rated voltage levels and maximum voltage for the equipment
The rated frequency of the electrical system shall be 50 Hz or 60 Hz.
In LV 50 Hz systems, rated phase to phase voltage shall be 400 V, 690 V or 230V.
In LV 60 Hz systems in onshore, rated phase to phase voltage shall be 400 V, 480 V, 230V or
240V.
In LV 60 Hz systems in offshore, rated phase to phase voltage shall be 400 V, 440 V, 480 V,
240V, 230V or 690 V.
Rated phase to phase voltages of 230V and 240V shall be used only in IT systems.
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In MV 50 Hz systems, rated phase to phase voltages shall be 6 kV, 6,6kV, 10 kV, 11 kV, 20
kV, 22 kV, 30 kV or 33 kV.
In MV 60 Hz systems, rated phase to phase voltages shall be 6 kV, 6,6kV, 10 kV, 11 kV, 13,8
kV, 20 kV, 22 kV, 30 kV or 33 kV.
In MV systems, highest voltage for equipment shall be according to IEC 60038:2021, Table 3.
2.7.1.4 Selection criteria of voltage levels
Motors rated above 5 MW shall be fed from a switchgear rated 10 kV or higher.
Motors rated above 315 kW and up to 5 MW shall be fed from a switchgear rated 6 or 6,6 kV.
Motors rated above 200 kW and up to 315 kW shall be fed from a switchgear rated 6 kV, 6,6
kV or 690V.
Motors rated up to 200 kW shall be in low voltage.
690V motors rated up to 132 kW shall be fed from a MCC or from the MCC section of a PMCC.
690V motors rated over 132 kW shall be fed from a PC or from the PC section of a PMCC.
LV motors with voltage lower than 690V and rated up to 75 kW shall be fed from a MCC or
from the MCC section of a PMCC.
LV motors with voltage lower than 690V and rated over 75 kW shall be fed from a PC or from
the PC section of a PMCC.
Single phase loads in TN systems shall be at 230V.
Phase to phase loads in 50 Hz IT systems shall be at 230V.
Phase to phase loads in 60 Hz IT systems shall be at 230V or 240V.
DC UPS system output shall be 110 V DC, with the possible exception of DC UPS part of a
VENDOR package.
AC UPS system output shall be 230V at 50 Hz.
AC UPS system output shall be 230V or 240V at 60 Hz.
2.7.1.5 Voltage drops
In steady state operating conditions, voltage drop from generator to downstream switchgear
shall not be higher than 2%.
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In steady state operating conditions, voltage drop from transformer to downstream switchgear
shall not be higher than 2%.
In steady state operating conditions, voltage drop between switchgear without interposed
transformers and located in the same electrical room building shall not be higher than 1%.
In steady state operating conditions, voltage drop along power transmission lines connecting
two different plants shall not be higher than 5%.
In steady state operating conditions, voltage drop between switchgear and MV motor shall not
be higher than 3%.
In steady state operating conditions, voltage drop between ASP or LP and end users shall not
be higher than 3%.
Voltage drop between UPS and end users shall not be higher than 5%.
Voltage drop between batteries and AC UPS shall not be higher than 2% with the higher
between maximum charger current and the maximum direct current that the inverter can
absorb.
Voltage drop between batteries and DC UPS shall not be higher than 2% with the higher
between maximum charger current and the maximum direct current that the DC UPS can
absorb from the batteries.
In steady state conditions, the sum of voltage drops of the various sections of a circuit, from
the generator or transformer to the terminals of the final load, shall be less or equal to 5 % of
the rated voltage of the circuit itself.
The voltage drop at MV switchgear shall not exceed 10% during motor starting.
The voltage drop at LV switchgear shall not exceed 15% during motor starting.
2.7.1.6 Voltage and frequency variation
Under steady-state conditions, voltage at generator and users terminals shall not deviate from
the rated equipment voltage by more than 5%.
Under steady-state conditions, system frequency shall not deviate from the rated frequency by
more than 2%.
Under steady-state conditions, the combined voltage and frequency deviations at generator
and users terminals shall lie within Zone A as defined in IEC 60034-1:2022, subclause 7.4.
The negative-sequence components of voltage at single-speed motor terminals shall not
exceed the limits indicated in IEC 60034-1:2022, subclause 7.2.1.1.
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Negative-sequence currents at the terminals of a synchronous machine shall not exceed the
limits indicated in IEC 60034-1:2022, subclause 7.2.3.
The voltage unbalance at any point in the system shall not exceed the limit indicated for Class
2 in IEC 61000-2-4:2002, Table 1.
Transient voltage deviations occurring at LV switchgear busbars during motor or group motor
starting shall be such as to maintain a minimum of 85% voltage on LV switchgear busbars,
and at least 80 %, but not more than 110 %, of rated equipment voltage on all other users.
Transient voltage deviations occurring at LV switchgear busbars during motor or group motor
reacceleration shall be such as to maintain a minimum of 85% voltage on LV switchgear
busbars, and at least 80 %, but not more than 110 %, of rated equipment voltage on all other
users.
Transient voltage deviations occurring at MV switchgear busbars during motor or group motor
starting shall be such as to maintain a minimum of 90% voltage on MV switchgear busbars,
and at least 80 %, but not more than 110 %, of rated equipment voltage on all other users.
Transient voltage deviations occurring at MV switchgear busbars during motor or group motor
reacceleration shall be such as to maintain a minimum of 90% voltage on MV switchgear
busbars, and at least 80 %, but not more than 110 %, of rated equipment voltage on all other
users.
During motor or group motor starting, the voltage at the motor terminals shall not deviate by
more than +10 % or –20 % from rated equipment voltage.
During motor or group motor reacceleration, the voltage at the motor terminals shall not
deviate by more than +10 % or –20 % from rated equipment voltage.
The limits set by the external power SUPPLIER regarding the maximum voltage deviations that
a consumer is permitted to cause at the point of common coupling shall be adhered to.
2.7.1.7 Maximum value of rated current on switchgears bus-bars
The rated continuous current of MV switchgear shall not be higher than 4000 A.
The maximum initial symmetrical short-circuit current on the busbars of ASP and LP switchgear
and on the busbars of the section of PMCC feeding small power loads shall be lower than 20 kA.
2.7.2
Power factor
If the electrical system is connected to an external network, the power factor calculated in
steady state operating conditions at battery limit point shall not be less than 0,92 lagging.
If the electrical system is connected to an external network, the power factor calculated in
steady state operating conditions at battery limit point shall not be leading.
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If the electrical system is not connected to an external network, the power factor calculated at
main power generator terminals shall not be less than 0,8 lagging.
If the electrical system is not connected to an external network, the power factor calculated at
main power generator terminals shall not be leading.
2.7.3
Harmonic distortion
The individual harmonic voltage distortions at any point of the system shall not exceed the
levels defined in IEC/TR 61000-3-6 table 1.
The Total Harmonic Distortion (THD) at any point of the system shall not exceed 8%.
Requirements related to harmonic distortion shall be satisfied with the main power sources
designated as spares in shut down.
If the main power source consists in power generators in parallel with external network, the
requirements related to harmonic distortion shall be satisfied also when all the main power
generators are in shut down.
Requirements related to harmonic distortion in essential distribution shall be satisfied also
when the system is powered by essential generators only.
Requirements related to harmonic distortion in emergency distribution shall be satisfied also
when the system is powered by emergency generators only.
The electronic devices shall be suitable for electromagnetic environment class 2 according to
IEC 61000-2-4.
Equipment shall be capable to operate continuously in the conditions present on the network at
point of installation, considering also emergency conditions such as operation with emergency
power source.
2.7.4
Neutral earthing
2.7.4.1 Medium Voltage systems
MV system neutrals shall be earthed by means of neutral earthing resistors, with the possible
exception of parts of the network connected to an external electrical energy SUPPLIER without
interposed transformers.
For parts of the network connected to an external electrical energy SUPPLIER without
interposed transformers, the neutral earthing philosophy of the external network shall be
adopted.
In MV systems, the neutral conductor shall not be distributed.
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The rating of the neutral earthing resistors shall be designed to limit the maximum earth fault
current to a value that does not damage the equipment (generator or power transformer) for
the time necessary for the intervention of the protections.
The resistive current of the NER shall be equal or higher than the 110% of the capacitive earth
current of the system during an earth fault.
Neutral earthing of a system with more than one generator connected to a MV switchgear
without step-up transformers shall be realized by means of individual neutral earthing resistors
connected to the generator start points, or by means of neutral earthing transformers.
If the solution with neutral earthing transformers is adopted, a neutral earthing transformer
shall be connected to each busbar of the MV switchgear to which the generators are
connected.
If MV generators are connected to the switchgear by means of step-up transformers, each
generator shall be provided with its own neutral earthing resistor, always connected during
operation.
If generators are connected to a MV switchgear by means of step-up transformer, the neutral
earthing on switchgear side shall be realized by means of neutral earthing transformers.
If a MV switchgear can be fed simultaneously by transformers and generators, the neutral
earthing shall be realized by means of neutral earthing transformers.
Individual neutral earthing resistors of generators to be operated in parallel with other units
shall be connected to the star point of the machine by means of a contactor, circuit breaker or
switch.
A neutral earthing transformer shall be constituted by a zigzag transformer or by a star/delta
transformer with open delta.
In zigzag transformers used for neutral earthing, the neutral earthing resistor shall be
connected to the star point of the zigzag transformer.
In star/delta transformers with open delta used for neutral earthing, the neutral earthing
resistor shall be connected in the open delta.
The contactor, circuit breaker or switch connecting the neutral earthing resistor with generator
star point shall be commanded by a control logic based on the status of generator circuit
breakers and switchgear bus ties.
If the solution with neutral earthing transformers is adopted, a control logic shall connect and
disconnect the neutral earthing transformers, based on the status of the MV switchgear bus
ties and of the circuit breakers of the neutral earthing transformers.
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The control logic managing the connection of neutral earthing resistors or of neutral earthing
transformers shall operate in such a way that only one neutral earthing resistor is connected in
each MV electrically separated system.
The control logic managing the connection of neutral earthing resistors or of neutral earthing
transformers shall operate in such a way that each electrically separated system does not
result to be in neutral isolated condition.
Control logics used to manage the connection of the neutral earthing resistors, or of the
neutral earthing transformers, shall be hardwired.
Control logics used to manage the connection of the neutral earthing resistors, or of the
neutral earthing transformers, shall be operational even in case of fault of single generators.
Control logic used to manage neutral earthing transformers shall be implemented in the
switchgear to which the neutral earthing transformers are connected.
It shall be possible to manually disable the control logic managing the connection of neutral
earthing resistors or of neutral earthing transformers.
If the control logic managing the connection of neutral earthing resistors or of neutral earthing
transformers is disabled, an alarm shall be raised to the EMS.
If a MV system normally earthed with resistor results to be in a neutral isolated condition, an
alarm shall be raised to the EMS.
For each MV electrically separated system, only one neutral earthing resistor shall be
connected at a time, except during short time parallel operations, such as the closing of a bus
tie and the opening of an incomer.
If during short time parallel operations in an electrically separated MV system more than one
neutral earthing resistor is momentarily connected at the same time, the condition of only one
neutral earthing resistor for each electrically separated system shall be restored automatically.
The status of the connection of neutral earthing resistors and neutral earthing transformers
shall be visible in the EMS graphic pages.
In MV systems with control logics managing the connection of neutral earthing resistors or of
neutral earthing transformers, a back-up protection sensible to voltage unbalance (such as
59N) shall be provided.
2.7.4.2 LV systems
LV systems in onshore plants and not fed from UPS shall have solidly earthed neutral (TN
system), in accordance with IEC 60364-1, with the exception of locations fed in low voltage
from the plant but located outside of the plant earth electrode area.
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NOTE: such systems (pipeline valve stations, fences) are fed with TT system through isolation
transformer and described in 2.10.4.4, 2.10.4.6, 2.10.4.8.
LV systems in offshore platforms and not fed from UPS shall have solidly earthed neutral (TN
system), in accordance with IEC 61892-2.
LV systems in FPSOs and floaters shall be IT with neutral isolated, in accordance with IEC
61892-2, with exception of distribution to lighting and small power users in living quarters, and
of electrical resistance trace heating.
Distribution to lighting and small power users in living quarters of FPSOs and floaters shall
have solidly earthed neutral (TN system), in accordance with IEC 61892-2.
Distribution to electrical resistance trace heating in FPSOs and floaters shall be IT with neutral
isolated or TN.
LV systems fed from AC UPS shall be IT with neutral isolated, in accordance with IEC 60364-1
for onshore facilities and with IEC 61892-2 for offshore facilities.
LV systems fed from DC UPS shall be IT with poles isolated, in accordance with IEC 60364-1
for onshore facilities and with IEC 61892-2 for offshore facilities.
In TN systems, the connection between generator or transformer to the downstream
switchgear shall have the line conductors and the PEN conductor.
In TN systems, the PEN conductor shall be separated in PE and neutral in the switchgear
immediately downstream of the generator or transformer.
In TN systems, the neutral shall be earthed inside the switchgear immediately downstream of
the generator or transformer.
In TN systems, after the switchgear immediately downstream of the generator or transformer,
the system shall be TN-S.
In TN systems, the connection between generator or transformer and the switchgear
immediately downstream shall not be routed through hazardous areas.
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Figure 1: typical interconnecting between LV generator and switchgear in TN
systems
Figure 2: typical interconnecting between MV/LV power transformer and switchgear
in TN systems
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Figure 3: typical interconnecting between LV/LV power transformer and switchgear
in TN systems
Figure 4: typical LV distribution in TN systems
2.7.4.3 LV IT systems
The neutral of IT systems shall not be distributed.
LV IT systems shall be provided with insulation monitoring device.
The insulation monitoring device for LV IT systems shall raise an alarm to the EMS in case of
earth fault.
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The insulation monitoring device for LV IT systems shall identify the faulty feeder by visual
indication on the front of the switchgear.
2.7.5
Power distribution configuration
Power distribution between MV switchgears inside plants shall be double radial.
Power distribution inside plants shall be double radial to PC, PMCC, MCC and ASP.
2.7.6
Electrical protection
2.7.6.1 General
The coordination and selectivity among protections devices shall be guaranteed in order to
avoid unnecessary trips in case of fault.
The coordination and selectivity study shall be implemented considering that the failure
downstream of any protection device in a switchgear shall not compromise the power supply to
other feeders.
The protection relays shall be equipped with a lock out relay (K86) with local manual reset.
Electrical protections shall be fed from UPS.
Incomers and feeders of LV and MV switchgears shall be equipped with hardwired trip contacts
activated by a dedicated SIS signal in order to open the involved circuit breaker or contactor.
For ASP and UPS distribution boards, hardwired trip contacts activated by dedicated SIS
signals shall be foreseen, in order to disconnect single users or groups of users.
Trip signal from SIS shall be permanent type and resettable only by SIS.
If the circuit breaker of contactor object of a trip signal from SIS is already open, the trip
signal shall inhibit its closure.
Alarm against water leakage shall be provided for all electrical equipment that use cooling with
water.
2.7.6.2 Short circuits protections
All equipment shall be capable to withstand the effects of short circuits as a minimum for the
time necessary for the intervention of the relevant protections.
The maximum short circuit current shall be calculated as indicated in 20231.ENG.ELE.PRG.
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For the calculation of the maximum short circuit current, the values of the voltage factor c
shall not be lower than recommended in IEC 60909-0.
Short circuit currents shall not exceed the design rating of the installation, with the only
possible exception of make-before-break switching operation between incomers and bus tie
circuit breakers of a switchgear, for the time necessary for the switching operation.
Short circuit currents exceeding the design rating of the installation for the momentary parallel
between generators shall not be permitted.
Short circuit currents exceeding the design rating of the installation for the momentary parallel
of generators with external network or transformer shall not be permitted.
The use of protective device with a short-circuit breaking or making capacity lower than
maximum prospective short-circuit current at the point where it is installed shall not be
permitted, unless the circuit is protected with a destructive Fault Current Limiter (FCL).
Destructive Fault Current Limiters (FCL) shall not be permitted in new onshore plants
(“greenfield”).
Destructive Fault Current Limiters (FCL) shall be permitted in case of expansion of existing
facilities (“brownfield”), if the maximum prospective short circuit current calculated for the
expansion exceeds the rating of equipment installed before the expansion.
Destructive Fault Current Limiters (FCL) shall be permitted in new offshore facilities at 50 Hz, if
connected to, or part of, a 11 kV switchgear with rated short time withstand current of at least
50 kA, fed directly by main power generators.
Destructive Fault Current Limiters (FCL) shall be permitted in new offshore facilities at 60 Hz, if
connected to, or part of, a 13,8 kV switchgear with rated short time withstand current of at
least 50 kA, fed directly by main power generators.
In LV, TN and TT systems, circuit breakers with associated residual current relays shall be used
for the protection against indirect contacts of the final users.
In LV IT system, in case the protection against indirect contact is performed by means of
magneto-thermic circuit breakers, the impedance of the fault loop shall be verified.
The protections shall intervene also in case of minimum short circuit current at the end of the
line.
If necessary to guarantee the intervention of the protections in case of fault, dedicated field
distribution panels shall be foreseen for lighting, small power and heat tracing.
In TN systems, incomers directly fed from generators or transformers shall be provided with
protections against earth fault.
In TN systems, feeders shall be provided with protections against earth fault.
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Electrical motors rated 3 MW and over shall be provided with motor differential protection
(87M), phase shifting type.
2.7.6.3 Overloads protections
Overloads protections shall be provided for all the circuits with the exclusion of rotating
machines excitation circuits, lifting electromagnets supply circuits, current transformers
secondary circuits, connection of batteries to UPS, connection of batteries to engine starting
systems, emergency diesel generators used in emergency conditions and other equipment that
for safety reasons have to operate even in case of overload.
Emergency diesel generators and other equipment that for safety reasons have to operate
even in case of overload shall be protected against overload when operated for testing
purposes.
2.7.7
Inter-tripping and interlocking
Inter-trip and interlock functions between upstream and downstream switchgear foreseen in
28880.ENG.ELE.STD and in 28881.ENG.ELE.STD shall be provided.
A key interlock shall be provided in MV switchgear between each earthing switch installed on
the front and the removable cover or door on the rear corresponding to the same functional
unit, in such a way that it shall be impossible to remove the cover or door unless the earthing
switch is in earthed position.
A key interlock shall be provided between earthing switch on MV switchgear feeder and
removable cover or door related to potentially live parts of the functional unit of the
corresponding LV incomer, in such a way that it shall be impossible to remove the cover or
door unless the earthing switch is in earthed position.
For LV switchgear located in different rooms, a key interlock shall be provided between LV
feeder and removable cover or door related to potentially live parts of the functional unit of the
corresponding LV incomer, in such a way that it shall be impossible to remove the cover or
door unless the upstream feeder is open, and withdrawn if applicable.
An interlock shall be foreseen between earthing switch on an incomer and corresponding
feeder on upstream switchgear, to avoid the risk of energization of an earthed circuit.
An interlock shall inhibit the starting, crank and slow roll of a generator if the switchgear
incomer to which it is connected has the earthing switch in earthed position.
A key interlock between the generator and the earthing switch of the corresponding switchgear
generator incomer shall inhibit the closure of the earthing switch when the generator is not
completely stopped, to avoid the risk of energization of an earthed circuit.
Electrical interlocks and inter-trips shall be hardwired or with IEC 61850.
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The use of IEC 61850 for interlocks and inter-trips shall be subject to the demonstration of its
functionality during integrated factory acceptance test between EMS and switchgear.
Electrical interlocks shall be fail-safe.
2.7.8
Earthing and lightning protection system
2.7.8.1 Earthing system
The earthing system shall be in accordance with IEC 60364 for low voltage onshore
installations.
The earthing system shall be in accordance with IEC 61936-1 and EN 50522 for onshore power
installations exceeding 1 kV a.c.
The earthing system of offshore facilities shall comply with IEC 61892 series.
For onshore plants, earth resistivity shall be evaluated according to COMPANY standard
02947.ENG.ELE.STD.
If MV or HV equipment are present, a global earthing system shall be adopted for the entire
facility, according to the definition of IEC 61936-1 and EN 50522.
In onshore plants, an earthing system calculation report shall be developed according to
20231.ENG.ELE.PRG.
The earthing system in an onshore plant shall be realized with horizontal buried bare
conductors combined with vertical rods.
The earthing system materials shall be chosen according to the degree of soil corrosivity.
The earthing system materials shall not create galvanic coupling with other buried metallic
structures.
If the earth electrode is connected to a cathodic protection system, the grounding system
material shall be galvanized steel instead of copper.
The compatibility of earthing system and cathodic protection system shall be verified.
In case of electrical system connected to external network, the earthing system shall be sized
considering the maximum earth fault currents and the fault clearance time of protective device
as per external power SUPPLIER requirements.
The sizing of the earth electrode shall comply with lightning protection requirements and
recommendations, according to IEC 62305 series.
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The instrumentation earthing system shall be connected to the electrical earthing system
according to COMPANY standard 20532.ENG.STA.STD.
2.7.8.2 Protection against lightning
Protection against lightning shall comply with IEC 62305 (all parts), both onshore and offshore.
Lightning protection measures in manned plants shall be designed according to LPL I.
Lightning protection measures in unmanned installations shall be designed according to LPL I
or LPL II.
Early streamer emitters shall not be used.
Dissipation array systems shall not be used.
In the evaluation of the potential risks according to the criteria of IEC 62305 series, it shall be
considered that the damage to UPS, emergency generator, emergency switchgear, systems
necessary for safe plant shut-down and systems necessary for evacuation could endanger
human life.
Concerning earthing and equipotential bonding, the requirements and recommendations of IEC
62305-3 shall be applied.
Concerning earthing and equipotential bonding, the requirements and recommendations of IEC
62305-4 shall be applied.
For the provision of SPD, the requirements and the recommendations of IEC 62305-4,
including Annexes C and D, shall be followed.
Lightning protection system for electronic devices shall comply with COMPANY standard
20531.ENG.STA.STD.
The protection of exposed vents against the possibility of lightning strike shall be verified.
2.7.9
Emergency electrical system
The emergency electrical system shall be able to feed all emergency loads.
The emergency power generation system shall be physically separated from the main power
generation.
The emergency power generation system shall consist in one, or more than one, emergency
diesel generators, with the possible exception of unmanned facilities.
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The emergency power generation system of unmanned facilities shall consist either in
emergency diesel generator, UPS or cable from another facility fed from the emergency diesel
generator of the other facility.
Emergency diesel generators shall be in low voltage.
An emergency generator shall have a maximum power rating of 3150 kVA at a power factor of
0,8 lagging, according to the definition of ISO 8528-1.
The emergency power generation shall be sized considering the total plant demand load of
emergency loads, plus contingency.
NOTE: contingency requirements are included in 2.7.1.2.
The emergency power generation system shall be capable of starting without relying on
external auxiliary systems.
The emergency power generation system shall be capable of connecting to the emergency
switchgear without relying on auxiliary systems external to the emergency generation system
itself.
The emergency power generation system shall be capable of feeding the UPS without relying on
auxiliary systems external to the emergency generation system itself.
The emergency power generation system shall not rely on cooling by means of a source
external to the package, such as process water or sea water.
The emergency electrical distribution shall be derived from the main distribution system.
The emergency electrical distribution shall have the possibility to be fed by emergency diesel
engine generator, in addition to main power sources.
Emergency power distribution shall be realized according to the configurations shown in LVS
906 or LVS 905 of 28880.ENG.ELE.STD.
The emergency generators shall start in automatic in case of lack of voltage in the emergency
switchgear to which they are connected.
In case of main power supply loss in onshore facilities, the power supply to all preferential
users shall be guaranteed within 3 minutes.
In case of main power supply loss in offshore facilities, the power supply to emergency users
shall be guaranteed as indicated in IEC 61892-2.
NOTE: in some countries (e.g. Italy) the local regulation requires the segregation between
emergency electrical room and normal electrical room in offshore facilities.
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Following the connection of the emergency generator to a de-energized busbar, the loads shall
be connected by means of an automatic time sequence, with the aim to ensure the stability of
the network.
The automatic time sequence for the connection of the loads shall not cause the instability of
the emergency power generation.
For FPSO and floaters, the emergency switchgear to which emergency generator is connected
shall be separate, and in different room, with respect to normal and essential switchgear.
Distance between emergency diesel generator and relevant substation shall not be higher than
30m.
If different stand-alone emergency systems are foreseen, each emergency diesel generator
shall be located close to the relevant substation.
Transfer of the load between emergency generator and main power source shall happen
without any power supply interruption.
The power supply to safety users shall be guaranteed by UPS with back-up batteries.
The apparent power of an emergency generator shall not be less than twice the sum of the
rated apparent output powers of all the UPSs that it feeds in emergency conditions.
Only one out of two UPS units redundant with each other shall be considered in the verification
of the rated apparent power of the emergency generator.
2.7.10 Black start requirements
The electrical system of the plant shall be capable of being energized starting from total shut
down conditions.
A black start philosophy shall be developed to describe the equipment necessary for black start
and the black start sequence.
The override of the SIS trip signals which are necessary for the plant black start shall be
achieved with an auto-reset logic circuit, commanded with a local device.
The SIS trip signals override shall be auto-reset upon SIS reactivation.
If the SIS signal override is active, an alarm shall be raised to the EMS and to the SIS, with
indication of the involved device.
If the SIS signal override is active, an alarm shall be raised in front of the involved equipment.
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2.7.11 Motor starting system selection
Electrical motors not part of an adjustable speed electrical power drive system shall be started
direct-on-line or with a soft-starter.
2.7.12 Electrical Management System (EMS)
EMS shall be provided.
EMS shall comply with 20180.ENG.ELE.STD.
Interface of equipment with the EMS shall comply with 20180.ENG.ELE.STD.
2.7.13 Electrical studies and reports
Electrical system calculations and related reports shall be performed as indicated in
20231.ENG.ELE.PRG.
2.7.14 Transformer impedances
Power transformers with the same rated power that feed the same switchgear shall have the
same short circuit impedance, within tolerance limits indicated in IEC 60076-1.
2.7.15 Electrical system for offshore facilities
Electrical system for offshore facilities shall comply with IEC 61892 series.
2.8
ELECTRICAL EQUIPMENT DESIGN AND SELECTION CRITERIA
2.8.1
Selection of protection methods against explosion and fire hazards
Electrical equipment in hazardous areas shall be selected and installed in compliance with IEC
60079 series.
Electrical equipment for hazardous areas shall be certified for gases in group IIB as a
minimum.
Electrical equipment for hazardous areas shall be certified for temperature class T3 as a
minimum.
Type of protection “p” shall not be used for preferential users.
LV motors installed in Zone 1 or Zone 2 shall have level of protection “db” “eb” or “eb”.
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MV single-speed motors installed in Zone 1 or Zone 2 shall have level of protection “eb”, “db”
“eb”, “pxb” or “pxb” “eb”.
Type of protection “p” for MV single-speed motors shall not be used if levels of protection “eb”
or “db” “eb” are available on the market for the required ratings of the motor.
MV converter-fed motors installed in Zone 1 or Zone 2 shall have level of protection “db” “eb”,
“pxb” or “pxb” “eb”.
Type of protection “p” for MV converter-fed motors shall not be used if level of protection “db”
“eb” is available on the market for the required ratings of the motor.
If type of protection “p” is used, in the conditions when the IEC 60079-14 foresees alarm only
in case of loss of pressurization, the equipment shall also be switched off.
If installed in non-hazardous areas, electrical bulk materials shall be industrial type as a
minimum.
Luminaires shall comply with 28914.ENG.ELE.STD.
Luminaires with incorporated battery shall always be certified EPL “Gb” as a minimum,
including local accessories and junction boxes.
Outdoor emergency escape lighting shall always be certified EPL “Gc” as a minimum, including
local accessories and junction boxes.
Junction boxes shall comply with 28915.ENG.ELE.STD.
Socket outlets and plugs shall comply with 28915.ENG.ELE.STD.
Motor control stations shall comply with 28915.ENG.ELE.STD.
Cable glands shall comply with 28915.ENG.ELE.STD.
Outdoor bulk materials not comprised in 28914.ENG.ELE.STD or 28915.ENG.ELE.STD and
containing current carrying parts shall have a minimum protection degree of IP55.
Indoor bulk materials not comprised in 28914.ENG.ELE.STD or 28915.ENG.ELE.STD and
containing current carrying parts shall have a minimum protection degree of IP44.
Offshore outdoor equipment shall have a degree of protection of IP 56 or IP 66, with exception
of lighting fixtures.
Offshore outdoor lighting fixtures shall have a degree of protection of IP 65 or IP 66.
Battery isolator box shall have level of protection “db” “eb” in all installation locations.
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If level of protection “db” is used, the terminal boxes shall be protected “eb” (e.g. indirect
cable entry protection “db” “eb”).
In offshore facilities, the requirements of ignition source control indicated in IEC 61892-1 shall
be followed.
In offshore facilities, electrical bulk materials shall be certified EPL “Gc” also if installed in
outdoor non-hazardous areas.
In offshore facilities, electrical resistance heat tracing systems located outdoors, or required to
fulfil the requirements for installation in hazardous area due to ignition source control
principles indicated in IEC 61892-1, shall comply with IEC/IEEE 60079-30-1 and IEC/IEEE
60079-30-2.
2.8.2
Power generation systems
2.8.2.1 Main power sources
The main power source shall be capable to feed all the users installed in the plant.
The main power source shall be capable to cover the total plant demand load plus contingency.
NOTE: contingency requirements are included in 2.7.1.2.
The main power source shall consist in main power generators, in an external network or in a
combination of the two.
If any one of the main power generators is unavailable, the other main power sources shall be
capable to cover the total plant demand load plus contingency, in the whole range of operating
site conditions.
If there is no external power supply network, the minimum number of main power generators
shall be three.
If both main power generation and external network connection are present, a system to avoid
the shut-down of the main power generation in case of sudden loss of the external network
shall be provided, including load shedding as necessary.
2.8.2.2 External network connection
If both main power generation and external network connection are present, the external
network incomer shall be provided with bi-directional measurement of active power, reactive
power, active energy, reactive energy.
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If both main power generation and external network connection are present, a directional
protection shall be provided to avoid the disconnection of the main power generation in case of
fault on the upstream network.
If both main power generation and external network connection are present, the incomer from
external network shall be provided with check synchronizing relay.
The check synchronizing relay provided on the incomer from external network shall not inhibit
the closure on dead bus.
If both main power generation and external network connection are present, facilities to
synchronize the running generators with the external network shall be provided as part of the
EMS, as indicated in COMPANY Standard 20180.ENG.ELE.STD.
The requirements imposed by the external power SUPPLIER in terms of power factor,
sectioning equipment, measuring equipment, protections, harmonic content and exchanged
power shall be complied with.
2.8.2.3 Essential power generation system
In FPSOs and floaters, essential power generation shall be provided in addition to main and
emergency power generation.
Essential power generation shall be constituted by diesel engine generators.
In case of loss of main power sources, essential generators shall be capable to start and to
connect to the loads even if the emergency power generation is not operational.
Contrary to what is indicated in IEC 61892-2, subclause 4.2.1, essential power generators shall
not be used to fulfill the N+1 sparing philosophy of main power generators.
The essential power generation shall be sized considering the total plant demand load of
preferential loads, plus contingency.
NOTE: contingency requirements are included in 2.7.1.2.
In case essential power generation is necessary for the black start of the facility, or to restore
the main power sources following a shut-down, essential power generators shall be in N+1
sparing philosophy.
2.8.2.4 Generating sets
Electrical generators driven by gas turbines, steam turbines or RICE shall be synchronous
machines.
The power rating of the generating sets shall be sized for continuous service in the whole
range of operating site conditions.
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The kW rating of the synchronous generator in continuous service shall be higher than the
output of the prime mover, in the whole range of operating site conditions.
Different power sources available in the plant shall be capable to operate in parallel, even if
connected to different switchgear or if at different voltage levels.
The synchronous generator rated power factor shall be 0,8 lagging.
Considering continuous loads only, the power generated by a running gas turbine generator shall
not be lower than 50% of site rated power of the gas turbine generator, in the whole range of
site conditions.
Considering continuous loads only, the power generated by a running gas engine generator shall
not be lower than 50% of the continuous power (COP) of the gas engine generator, in the whole
range of site conditions.
Considering continuous loads only, the power generated by a running diesel engine generator
used as main power source shall not be lower than 50% of the continuous power (COP) of the
diesel engine generator, in the whole range of site conditions.
Generating sets shall be capable to interface with the EMS as indicated in 20180.ENG.ELE.STD.
Generating sets shall be capable of synchronizing in automatic and connecting to the
downstream switchgear upon receival of a starting command.
Generating sets shall be capable of connecting on dead bus upon receival of a starting
command.
RICE driven generators shall have performance class G2 or G3, according to ISO 8528-1, ISO
8528-5 and IEC 60034-22.
RICE driven generators with auxiliary or starting batteries shall be provided with alarm for low
voltage of battery incoming supply, visible in the unit control panel and in the EMS.
RICE driven generators, if not used as emergency generators, shall be designed for continuous
operation at varying load, as defined in ISO 8528-1.
RICE driven generators, if not used as emergency generators, shall be designed for the power
rating category of Continuous Power (COP), as defined in ISO 8528-1.
RICE driven emergency diesel generators shall be designed for limited time operation at
varying load, as defined in ISO 8528-1.
RICE driven emergency diesel generators shall be designed for power rating category COP, PRP
or LTP, according to ISO 8528-1.
The emergency diesel generators shall be provided with facilities for periodic offload and onload testing.
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Switchgears
2.8.3.1 General
In a switchgear, it shall not be permitted to use switching devices in parallel to achieve the
required rating.
Nameplates and labels for switchgear to be installed indoors shall be in plastic with embossed
letters.
Nameplates and labels for switchgear to be installed outdoors shall be in AISI 316L with engraved
letters.
Base frame, accessories for switchgear clamping, lift pad eyes or equivalent devices, shall be
provided.
If a switchgear busbar is de-energized, the main circuit switching devices controlling the starting
and stopping of the motors connected to it shall be opened.
Switchgear auxiliary power supply for space heaters, sockets and maintenance lighting shall be
provided from ASP.
In switchgears, auxiliary power supply for control, logic, opening and closing circuits, protections,
digital instruments, signalling lights and spring charging motors shall be fed by UPS, with the
only possible exception of contactors for LV switchgears.
Semiconductor converters used to derive auxiliary power supply inside a switchgear shall be
redundant in a 2x100% configuration.
Failure of a semiconductor converter used to derive an auxiliary power supply inside a switchgear
shall generate an alarm in the EMS.
Manual reset of protection devices shall not require the opening of functional unit compartments
of the switchgear.
Automatic transfer schemes of switchgear shall inhibit the energization of a faulty busbar.
The connection of two unsynchronized circuits of a switchgear shall be inhibited.
In switchgears, there shall be the possibility to inhibit the remote closing of the switching device
of a main circuit by means of a local selector switch.
For remotely controlled main circuit switching devices of a switchgear, the possibility to open
from remote shall not be influenced by the position of local/remote selectors located on the
switchgear.
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There shall be always the possibility to open the switching device of a main circuit from the front
of the switchgear, regardless of the position of local/remote selectors, unless there is a low
pressure condition on the insulating gas of the switching device.
It shall be possible to inhibit automatic transfer schemes in a switchgear by means of a local
selector switch.
If switchgears are installed outdoors, the minimum protection degree shall be IP 55.
2.8.3.2 MV Switchgears
MV switchgears shall comply with IOGP S-620 “Supplementary Specification to IEC 62271-200
High-voltage switchgear and controlgear”.
The acronym “ECMS” used in IOGP S-620 and related datasheets shall be considered equivalent
to the acronym “EMS” used in the present document.
The words “electrical control and management system” used in IOGP S-620 shall be considered
equivalent to the words “electrical management system” used in the present document.
Main device of AIS MV switchgear shall be withdrawable.
MV switchgears shall have accessibility type A.
In MV switchgear, identification of conductors by colour shall be the same used for the cables
connected to it.
Earthing switches of MV switchgear shall have classification of short-circuit making of E1 as a
minimum, according to IEC 62271-102.
Circuit breakers used in MV switchgear motor starters shall have mechanical endurance M2,
according to IEC 62271-100.
MV switchgear circuit breakers shall have electrical endurance class E2 according to IEC 62271100.
Voltage transformers in AIS MV switchgear shall be withdrawable.
AIS MV switchgears shall comply with COMPANY Standard 28881.ENG.ELE.STD.
Measurements of MV switchgears shall comply with COMPANY Standard 28881.ENG.ELE.STD.
In MV switchgear, switching medium of MV circuit breakers shall not be air.
In MV switchgear, switching medium of MV contactors shall not be air.
Controlled pressure systems for gas shall not be used in MV switchgear.
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The floor surface shall not be part of MV switchgear enclosure.
In MV switchgears, low voltage fuses shall not be permitted for the protection of power and
auxiliary circuits.
In MV switchgears, the communication of protection relays and multimeters shall comply with
20180.ENG.ELE.STD.
Interface of MV switchgear
20180.ENG.ELE.STD.
with
the
EMS
shall
comply
with
COMPANY
Standard
Network redundancy protocol for MV switchgears shall be as indicated in COMPANY Standard
20180.ENG.ELE.STD.
In MV switchgears, indicator light colour coding shall comply with 28881.ENG.ELE.STD.
LV auxiliary compartments of MV switchgear shall be provided with space heaters for the
prevention of condensation.
MV connection compartments of MV switchgear shall be provided with space heaters for the
prevention of condensation.
Motor starter functional units of MV switchgear shall be fitted with auxiliary circuits to feed motor
space heaters.
Auxiliary and control circuit cable insulation shall be low smoke, zero halogen.
With reference to IEC 62271-102:2022, subclauses 5.6, 5.7, 5.8, earthing switches in MV
switchgears shall not be assigned a different rating than the one of the main circuit.
In addition to the provisions already foreseen for future development phases, for each busbar
at the extremity of a new MV switchgear, at least one fully equipped MV/MV or MV/LV liquid
immersed transformer spare feeder shall be provided, rated as the maximum already installed
feeder of the same typology or 630A if the same typology is not present.
As a minimum, 10% unused spare terminals for control and auxiliaries shall be provided in MV
switchgears.
Inspection and testing activities on MV switchgear shall comply with CAS “A” of IOGP S-620Q.
EMS simulation test shall be performed for MV switchgears.
2.8.3.3 LV Switchgears
LV switchgears shall comply with IEC 61439 series.
LV switchgears shall comply with IOGP S-560 “Supplementary Specification to IEC 61439-1 & 2
Low-voltage Switchgear and Controlgear Assemblies”.
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The acronym “ECMS” used in IOGP S-560 and related datasheets shall be considered equivalent
to the acronym “EMS” used in the present document.
The words “electrical control and management system” used in IOGP S-560 shall be considered
equivalent to the words “electrical management system” used in the present document.
Inspection and testing activities shall comply with CAS “B” of IOGP S-560Q for LV switchgears
of PC, MCC and PMCC type, and with CAS “C” of IOGP S-560Q for other types of LV switchgear.
EMS simulation test shall be performed for LV switchgears.
In LV switchgears, the communication of protection relays and multimeters shall comply with
20180.ENG.ELE.STD.
Interface of LV switchgear
20180.ENG.ELE.STD.
with
the
EMS
shall
comply
with
COMPANY
Standard
Network redundancy protocol for LV switchgears shall be as indicated in COMPANY Standard
20180.ENG.ELE.STD.
LV switchgear shall interface with the EMS as indicated in 20180.ENG.ELE.STD.
LV switchgears shall be suitable for pollution degree 3 as a minimum, according to IEC 614391.
LV switchgears shall be suitable for EMC environment A, according to IEC 61439-1.
For LV switchgears, basic protection shall be achieved through constructional measures,
according to IEC 61439-1.
LV switchgears shall be of the PC, PMCC, MCC, ASP, LP, UPS distribution board, HVAC switchgear
or Local Distribution Panel type, according to the definitions indicated in the present document.
For LV switchgears in a rated system voltage lower than 690V, outgoing motor starter and
process heater feeder functional units shall be in withdrawable execution up to 75 kW.
For LV switchgears in a rated system voltage of 690V or higher, outgoing motor starter and
process heater feeder functional units shall be in withdrawable execution up to 132 kW.
For LV switchgears in a rated system voltage lower than 690V, outgoing motor starter and
process heater feeder functional units over 75 kW shall be in fixed execution, but with
withdrawable circuit breaker.
For LV switchgears in a rated system voltage of 690V or higher, outgoing motor starter and
process heater feeder functional units over 132 kW shall be in fixed execution but with
withdrawable circuit breaker.
Outgoing feeder functional units up to 250A other than motor starter, process heater and small
power shall be in withdrawable execution and fed from a LV switchgear of PMCC type.
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For LV switchgears, outgoing feeder functional units other than motor starter and process heater
over 250A and up to 630A shall be in fixed execution, but with withdrawable circuit breaker.
NOTE: outgoing feeders above 630A are with withdrawable ACBs as per IOGP S-560.
Incoming unit switching devices of LV switchgear of PC and PMCC type shall be withdrawable
ACBs.
Bus coupler switching devices of LV switchgear of PC and PMCC type shall be withdrawable ACBs.
Incoming unit switching devices of LV switchgears of ASP and LP type shall be withdrawable.
For LV switchgears of MCC type, incoming unit switching devices and bus coupler switching
devices shall be withdrawable.
For LV switchgears of HVAC type, incoming unit switching devices and bus coupler switching
devices shall be withdrawable.
In LV switchgear, fuses shall not be used, with the possible exceptions of the protection of VT
primary circuits and of the protection of semiconductor devices.
In LV switchgears, motor starter functional units shall have provision for motor space heater
supply.
In LV switchgear, test blocks for ACB protection relay injection testing shall be provided.
For LV switchgear including a neutral busbar, generator and transformer incomers shall be
provided with an accessible removable link between the neutral busbar and the protective earth.
LV switchgears shall be provided with enclosure space heaters.
In LV switchgears, assumed loading of circuits shall consider that spare equipment (e.g. spare
pumps) can be operational.
Auxiliary and control circuit cable insulation shall be low smoke, zero halogen.
In LV switchgear, identification of conductors by colour shall be the same used for the cables
connected to it.
LV switchgear motor feeders shall be provided with over temperature protection using thermistor
or RTD as a minimum for the motors for which it is foreseen in IOGP S-703.
In LV switchgear, for lighting and heat tracing circuits, the curve of intervention of the circuit
breaker shall be verified to check that the inrush current can be sustained without tripping.
LV switchgear of PC, PMCC and MCC type shall have arcing class B or C according to IEC TR
61641.
NOTE: All LV switchgears part of scope of applicability of IOGP S-560 are required to have at
least arcing class A according to IEC TR 61641.
ENGINEERING COMPANY STANDARD
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LV switchgear of PC, PMCC and MCC type used under emergency distribution shall have arcing
class C according to IEC TR 61641.
For LV switchgear with arc classification, permissible arc duration shall not be lower than the
time required for the intervention of the protections.
LV switchgear in TN systems shall comply with 28880.ENG.ELE.STD, with the possible exception
of HVAC switchgears.
AC UPS distribution boards shall comply with 28882.ENG.ELE.STD.
For each busbar of a LV switchgear of PMCC and MCC type, at least 10% fully equipped
withdrawable motor starter functional units shall be provided, with a minimum of two spare
drawers of rating equal to the maximum already present.
Spare functional units of the same rating shall be distributed as evenly as possible between
different busbars located at the extremities of a LV switchgear.
For each busbar of a LV switchgear of PC and PMCC type, in addition to the provisions already
foreseen for future development phases, at least one fully equipped spare feeder to ASP
switchgear shall be provided.
For each busbar of a LV switchgear of PC and PMCC type, at least one spare feeder to ASP
switchgear shall have a rating equal to the maximum already present of the same typology, or
630A if the same typology is not present.
For each LV switchgear of ASP or LP type, 20% fully equipped spare feeders shall be provided,
with at least one for each rating.
For each UPS distribution board, 20% fully equipped spare feeders shall be provided, with at
least one for each rating.
In LV switchgears, switching devices shall switch all phases or poles, with the exceptions
indicated in 28880.ENG.ELE.STD.
Indicator lights and indicator light colour coding shall be in accordance with
28880.ENG.ELE.STD for LV switchgears other than UPS distribution boards.
NOTE: this requirement is applicable also for LV switchgear not required to comply with
28880.ENG.ELE.STD, such as switchgears in IT systems and HVAC switchgears.
Measurements shall be in accordance with 28880.ENG.ELE.STD for LV switchgears other than
HVAC switchgear and UPS distribution boards.
NOTE: this requirement is applicable also for LV switchgear not required to comply with
28880.ENG.ELE.STD, such as switchgears in IT systems.
Indicator light colour coding shall be in accordance with 28882.ENG.ELE.STD for AC UPS
distribution boards.
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Form of internal separation for ACB functional units of LV switchgear shall be 4b.
In LV switchgear of HVAC type, if normal and emergency loads are fed by the same switchgear
(permitted only onshore), means to disconnect and to inhibit starting of non-emergency loads
shall be foreseen upon unavailability of main power source.
As a minimum, three phase voltage and current measurements shall be made available for each
incomer on the front of a LV switchgear of HVAC type.
If a Local Distribution Panel has different incoming power supplies, they shall feed different
segregated sections.
2.8.4
Power transformers
2.8.4.1 General
Power transformers, including LV/LV transformers, shall comply with IEC 60076 series.
Power transformers shall comply with IOGP S-720 “Supplementary Specification to IEC 600761 Transformers“.
Neutral earthing transformers shall be subject to the same requirements as power
transformers.
Cable connecting boxes of power transformers, if present, shall be separate for high voltage
side of the transformer, low voltage side of the transformer, the auxiliary circuits of the
transformers (such as CT secondaries and alarm/trip measuring devices), forced cooling
equipment terminals, neutral connection of transformers with secondary voltage > 1kV.
Power transformers, including LV/LV ones, shall be capable to sustain the thermal and dynamic
effects of short circuit, as specified in IEC 60076-5.
The ability of the power transformers to withstand the dynamic effects of short circuit shall be
demonstrated by calculations, design considerations and VENDOR considerations.
The values of apparent short circuit power of the network shall be used for the design of the
power transformers.
Rating plates of power transformers shall be made of stainless steel AISI 316L.
Power transformers shall be provided with de-energized tap changer, with a tapping range of
±5% as a minimum, in steps of maximum 2,5%.
Dry type power transformers shall not be installed inside a switchgear, with exception of
transformers feeding only internal auxiliaries of the switchgear itself and of transformers part
of a UPS.
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Liquid immersed transformers shall not be installed inside a switchgear.
Water cooled transformers shall not be installed inside a switchgear.
Transformers part of AC UPS shall comply with IOGP S-701 and are not treated in the present
paragraph.
Transformers part of DC UPS shall comply with IOGP S-702 and are not treated in the present
paragraph.
Two winding transformers with star connection both at primary and secondary windings shall
be rejected.
Power transformers connected to overhead lines or air insulated substations shall be protected
with surge arresters.
Feeding of PC and PMCC switchgear with MV/MV and MV/LV transformers is series shall not be
permitted, unless necessary for power distribution from an essential MV power source, or if the
MV/MV transformers are generator step-up transformers.
Autotransformers shall be permitted only if explicitly indicated in COMPANY standards.
LV/LV transformers feeding ASP or LP shall not be rated more than 500 kVA.
Bi-directional rollers shall be required for power transformers.
Wheel assemblies for power transformers shall be removable.
Pulling hooks shall be provided for towing the power transformer in both perpendicular
directions.
Power transformers shall be provided with a digital temperature control relay with alarm and
trip thresholds, to be installed in a switchgear connected to the transformer.
Power transformer auxiliary circuits shall be housed in marshalling boxes.
Air insulated main cable boxes of power transformers shall be provided with space heaters.
Marshalling boxes and auxiliary panels for power transformers shall be provided with space
heaters controlled with thermostat and protected with MCBs or with switch-disconnector-fuses.
Terminals of space heaters for power transformer enclosures, boxes and auxiliary panels shall
be provided with a warning label.
Space heaters for power transformer enclosures, boxes and auxiliary panels shall be protected
to at least IP2X.
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Space heaters for power transformer enclosures, boxes and auxiliary panels shall be provided
with a mechanical guard if the surface temperature exceeds 60°C.
Motor starters included in power transformer auxiliary panels shall be least provided with
protection with thermomagnetic circuit breakers.
Additional accessories, sensors and protections included in VENDOR recommendations for
power transformers shall be provided.
Inspection and testing activities on power transformers shall comply with CAS “C” of IOGP S720Q as a minimum.
2.8.4.2 Dry type power transformers
Dry type power transformer shall be resin insulated.
Dry type power transformers shall comply with IEC 60076-11.
Dry type power transformers with at least one MV winding shall have insulation in class F and
temperature rise limited to 80 K in normal service conditions as defined in IEC 60076-11.
In normal service conditions as defined in IEC 60076-11, LV/LV dry type power transformers
shall have insulation in class F and temperature rise limited to 80 K, or insulation in class H
and temperature rise limited to 100 K.
If the temperature of the cooling medium exceeds the normal service conditions, the
requirements of temperature rise limits for dry type power transformers shall be modified
according to IEC 60076-11:2018, subclause 10.2.
The partial discharge measurement for dry type power transformers operated under a single
phase line-to-earth fault condition, that is a special test mentioned in IEC 60076-11, shall be
performed for all transformers that operate in systems for which automatic disconnection is
not foreseen in case of first earth fault.
Dry type power transformers shall have fire behaviour class F1, according to IEC 60076-11.
Dry type power transformers shall have a climatic class in compliance with the conditions of
installation and storage and at least equal to C1, according to IEC 60076-11.
Dry type power transformers in environmentally controlled rooms shall have an environmental
class in compliance with the conditions of installation and at least equal to E1, according to IEC
60076-11.
Dry type power transformers in offshore or coastal areas, if installed outside of
environmentally controlled rooms, shall have an environmental class in compliance with the
conditions of installation and at least equal to E4, according to IEC 60076-11.
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Dry type power transformers in onshore non-coastal areas, if installed outside of
environmentally controlled rooms, shall have an environmental class in compliance with the
conditions of installation and at least equal to E3, according to IEC 60076-11.
Winding temperature detectors of dry type power transformers shall be of platinum of 100 Ω at
0°C (PT100).
If dry type power transformers are in an enclosure, only one transformer shall be housed in a
single enclosure.
Dry type power transformers shall not be installed outdoors without canopy.
Canopy for dry type power transformers shall be sloped to avoid the stagnation of water.
Dry type power transformers installed outdoors under canopy shall have an enclosure with a
minimum protection degree of IP54.
Dry type power transformers installed indoors, in a room enclosed on all sides and not
dedicated to a single transformer, shall have an enclosure with a minimum protection degree
of IP2X.
Dry type power transformers installed in a room or bay with one side opened to the outside by
means of grates or louvers, in which rain with inclination exceeding 60° from the vertical is
impeded to reach the transformer by means of barriers, shall have an enclosure with a
minimum protection degree of IP23.
Dry type power transformers installed in a room or bay with one side opened to the outside by
means of grates or louvers, in which rain with inclination exceeding 60° from the vertical is not
impeded to reach the transformer, shall have an enclosure with a minimum protection degree
of IP44.
Dry type power transformer enclosures for offshore and coastal areas shall be in AISI 316L.
Dry type power transformer enclosures for locations other than offshore or coastal areas shall
be in AISI 316L or galvanized steel.
Passage of single core cables through dry type power transformer enclosures shall not be
surrounded by magnetic materials.
Opening of a dry type power transformer enclosure shall be possible, by means of interlock,
only if the transformer is de-energized.
Interlocks for the enclosures of MV/MV and MV/LV dry type power transformers shall require
the upstream earthing switch to be in the earthed position before it is possible to open the
enclosure.
Dry type power transformers without enclosure shall be permitted only in a room or bay
dedicated to a single transformer and without open walls to the outside.
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A room or bay dedicated to a single transformer shall not include other equipment besides
transformer auxiliaries, transformer neutral earthing resistor, lighting, power sockets and
HVAC.
Protection barriers, grating and clearances of rooms and bays containing dry type power
transformers without enclosure shall comply with IEC 61936-1, both onshore and offshore.
Access to a room or bay containing a dry type power transformer without enclosure shall be
possible only if the transformer is de-energized, by means of key interlock.
Interlocks for the rooms and bays of MV/MV and MV/LV dry type power transformers shall
require the upstream earthing switch to be in the earthed position before it is possible to
access to the room or bay.
Dry type power transformers shall be provided with at least two earthing terminals for
connection to the earth electrode.
Dry type power transformer enclosures shall be provided with earthing terminals for
connection to the earth electrode.
2.8.4.3 Liquid immersed power transformers
Liquid immersed power transformers shall be provided with relief valve type pressure relief
devices with mechanical operation indicator.
Liquid filled cable boxes of power transformers shall be provided with a pressure relief device
with trip contacts.
Pressure relief devices for liquid immersed transformers shall be provided with a facility for
directing emissions of liquid from the relief device in the direction away from the transformer.
For liquid immersed transformers, the direction of emission of liquid from the pressure relief
device shall be away from the position of possible approach of an operator to the location in
which the transformer is installed.
Liquid immersed transformers shall be provided with liquid temperature indicator with alarm
and trip contacts.
Alarm contact for diaphragm failure shall be provided for liquid immersed power transformers
with diaphragm in conservator.
Liquid level indicator of the conservator of liquid immersed power transformers shall be
provided with an alarm contact.
Winding temperature detectors of liquid immersed power transformers shall be of platinum of
100 Ω at 0°C (PT100) or fiber optic temperature sensors.
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Liquid immersed transformers shall be installed outdoors or in bays with one wall opened to
the outside by means of grating or louvers.
The use of sealed transformers shall be limited to power ratings lower than 3150 kVA.
Sealed transformers shall be provided with sudden pressure relay.
In offshore facilities, liquid immersed transformers shall have internal cooling medium
indicated with letter “K” according to IEC 60076-2.
2.8.4.4 Selection criteria of power transformers
Power transformers shall be dry type resin insulated or liquid immersed.
Power transformers without windings rated more than 36 kV and with power rating not higher
than 15 MVA in natural ventilation shall be dry type resin insulated, if not installed in desert
locations or locations in which sand or dust storms are expected.
Power transformers with at least a winding rated more than 36 kV or with power rating higher
than 25 MVA in natural ventilation shall be liquid immersed.
In desert locations and wherever sand or dust storms are expected, dry type power
transformers resin insulated shall have a maximum power rating of 3,15 MVA with natural
ventilation and a maximum rated voltage of a winding of 36 kV.
In desert locations and wherever sand or dust storms are expected, dry type power
transformers resin insulated shall be installed indoors, in rooms surrounded on all sides, with
forced ambient ventilation.
Cooling method of dry type power transformers for onshore installation shall be AN or AN/AF,
according to IEC 60076-2.
Cooling method for dry type power transformers for offshore installation shall be AN, AN/AF or
AFWF, according to IEC 60076-2.
Cooling method AN/AF for dry type transformers shall be permitted only if the transformer is
required to be housed in an enclosure with degree of protection IP44 or higher.
Power transformer cooling methods based on water shall be permitted only if the water system
necessary for cooling is operational without need of prior energization of the transformer.
Cooling method of dry type power transformers remaining operational during emergency
conditions shall be AN, according to IEC 60076-2.
Liquid immersed transformers remaining operational during emergency conditions shall not
rely on forced cooling, water cooling or forced liquid circulation.
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2.8.5
20208.ENG.ELE.PRG
Rev. 14 – June 2022
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Reactors
2.8.5.1 General
Reactors shall comply with IEC 60076-6.
Reactors shall comply with IOGP S-720 “Supplementary Specification to IEC 60076-1
Transformers “.
Reactors part of an adjustable speed electrical power drive system shall comply with IOGP S736 or IOGP S-747, depending on voltage, and are not treated in the present paragraph.
Cable connecting boxes of reactor, if present, shall be separate for main power connection, the
auxiliary circuits of the reactor (such as CT secondaries and alarm/trip measuring devices),
forced cooling equipment terminals, on-load tap changer.
For reactors having mechanical short circuit current rating according to IEC 60076-6, the
ability to withstand the dynamic effects of short circuit shall be demonstrated by calculations,
design considerations and VENDOR considerations.
The values of apparent short circuit power of the network shall be used for the design of
reactors having mechanical short circuit current rating according to IEC 60076-6.
Winding temperature detectors of reactors shall be of platinum of 100 Ω at 0°C (PT100) or
fiber optic temperature sensors.
Reactors shall be provided with a digital temperature control relay with alarm and trip
thresholds, to be installed in the connected switchgear.
Reactor auxiliary circuits shall be housed in marshalling boxes.
Air insulated main cable boxes of reactors shall be provided with space heaters.
Marshalling boxes and auxiliary panels for reactors shall be provided with space heaters
controlled with thermostat and protected with MCBs or with switch-disconnector-fuses.
Terminals of space heaters for reactor enclosures, boxes and auxiliary panels shall be provided
with a warning label.
Space heaters for reactor enclosures, boxes and auxiliary panels shall be protected to at least
IP2X.
Space heaters for reactor enclosures, boxes and auxiliary panels shall be provided with a
mechanical guard if the surface temperature exceeds 60°C.
Motor starters included in reactor auxiliary panels shall be least provided with protection with
thermomagnetic circuit breakers.
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Additional accessories, sensors and protections included in VENDOR recommendations for
reactors shall be provided.
Reactors connected to overhead lines or air insulated substations shall be protected with surge
arresters.
Inspection and testing activities on reactors shall comply with CAS “C” of IOGP S-720Q as a
minimum.
Testing of reactors shall comply with IEC 60076-6.
2.8.5.2 Dry type reactors
Dry type reactors shall be designed for the pollution conditions of the installation site.
Lacking indications of pollution conditions at installation site, dry type reactors shall be
designed for very heavy pollution severity, according to the definitions of IEC TS 60815-1.
Magnetic clearance shall be verified for dry type reactors, in relation to the conditions of
installation.
It shall be verified that dry type reactors are protected from atmospheric effects (e.g. rain,
sun).
It shall be ensured that recommendations of VENDOR on magnetic clearance with respect to
nearby metallic objects and concrete rebars are respected for dry type reactors.
Dry type reactors shall be installed in a fenced area which shall be accessible, by means of
interlock, only when the equipment installed inside it are de-energized.
Fenced areas containing dry-type reactors shall not contain other equipment, apart from
reactor auxiliaries.
Dry type reactors that are redundant to each other shall not be installed in the same fenced
area.
2.8.5.3 Liquid immersed reactors
Liquid immersed reactors shall be provided with relief valve type pressure relief device with
mechanical operation indicator.
Liquid filled cable boxes of reactors shall be provided with a pressure relief device with trip
contacts.
Pressure relief devices for reactors shall be provided with a facility for directing emissions of
liquid from the relief device in the direction away from the reactor.
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For liquid immersed reactors, the direction of emission of liquid from the pressure relief device
shall be away from the position of possible approach of an operator to the location in which the
reactor is installed.
Liquid immersed reactors shall be provided with liquid temperature indicator with alarm and
trip contacts.
Alarm contact for diaphragm failure shall be provided for liquid immersed reactors with
diaphragm in conservator.
Liquid level indicator of the conservator of liquid immersed reactors shall be provided with an
alarm contact.
Liquid immersed reactors shall be installed outdoors or in bays with one wall opened to the
outside by means of grating or louvers.
Liquid immersed reactors shall not be installed inside a switchgear.
In offshore facilities, liquid immersed reactors shall have internal cooling medium indicated
with letter “K” according to IEC 60076-2.
2.8.6
UPS equipment and batteries
2.8.6.1 General
UPS shall comply with IEC 62040 series.
UPS shall guarantee the supply of the connected loads in case of fault or unavailability of main
and emergency power sources.
For the design of the HVAC system, it shall be considered that the UPS generates heat also
when fed from the batteries only.
2.8.6.2 Selection of AC UPS scheme
The configuration of AC UPS shall be according to UPS 001, UPS 002 or UPS 003, as indicated
in 28882.ENG.ELE.STD, or according to type "D".
UPS 001 configuration, called AC UPS type “A”, shall consist in single rectifier/inverter unit
(1x100%), non-redundant batteries (1x100%) and bypass system.
UPS 002 configuration, called AC UPS type “B”, shall consist in parallel redundant
rectifier/inverter units (2x100%), redundant batteries (2x100%) and bypass system.
UPS 003 configuration, called AC UPS type “C”, shall consist in dual configuration
rectifier/inverter units (2x100%), redundant batteries (2x100%) and bypass system.
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AC UPS type “D” configuration, to be developed on project basis, shall consist in dual
configuration rectifier/inverter units (2x100%), non-redundant batteries (1x100%) and bypass
system.
AC UPS type “D” shall have one of the distribution sections foreseen in 28882.ENG.ELE.STD.
Transformers in AC UPS type “D” shall have the same redundancy of rectifiers and inverters.
In AC UPS, distribution section type “2” of 28882.ENG.ELE.STD shall be used only to feed
instrumentation and telecom loads which require redundant power supplies.
AC UPS units and bypass paths shall be fed from emergency busbars.
If two AC UPS of type “A” are used, the two converter paths shall be fed from two different
emergency busbars.
If two AC UPS of type “A” are used, the two bypass paths shall be fed from two different
emergency busbars.
If UPS of type “B”, “C” or "D" is used, the two converter paths shall be fed from two different
emergency busbars.
At least two separate UPS shall be foreseen, one for electrical safety loads (such as switchgear
auxiliaries for control and protection, emergency escape lighting), and the other for
instrumentation and telecom loads (such as ICSS).
For instrumentation and telecom loads, AC UPS shall be used.
For electrical safety loads, AC UPS shall be used in all new facilities and for revamping of
existing facilities in which AC UPS for electrical safety loads is already present.
DC UPS shall be permitted for electrical safety loads only for revamping of existing facilities in
which other DC UPS is already present, or if VENDOR standard for packages (e.g. gas
turbines).
The configuration with only one AC UPS of type “A” shall be permitted only if the loads to be
fed are not related to people safety or equipment integrity.
The configuration with two AC UPS of type “A” shall be permitted only if the loads are fed
through redundant AC/DC converters, or if normative reasons (e.g. Class requirements)
impose to have two different UPS units in different locations.
If feeding loads without redundant AC/DC converters, the outputs of the two AC UPS of type
“A” shall be synchronized.
If feeding loads with single power supply from a configuration with two AC UPS of type “A”, an
intermediate panel shall be used, fed from both UPS and with a make-before-break automatic
transfer logic.
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Panels fed from AC UPS by means of static switches shall have a static switch for each
incomer.
If feeding a panel with an automatic transfer logic, the capacity of the inverter of the AC UPS
shall be verified against the inrush current of the loads.
AC UPS of type “C” shall be used only to feed instrumentation and telecom loads which require
redundant power supplies.
AC UPS of type “B” shall be used only to feed electrical safety loads and loads that do not
require redundant power supplies.
AC UPS of type “D” shall be used only with SMC batteries.
If AC UPS of type “D” is used, one additional battery module shall be provided with respect to
the required autonomy.
The inverter outputs of AC UPS of type “B” shall be synchronized.
2.8.6.3 AC Uninterruptible Power Supply System
AC UPS shall comply with IOGP S-701 “Supplementary Specification to IEC 62040-3 AC
Uninterruptible Power Systems (UPS)”.
AC UPS shall comply with 28882.ENG.ELE.STD, if AC UPS type "D" is not used.
AC UPS shall be suitable for ambient with pollution degree 3 as per IEC 62477-1.
AC UPS topology shall be double conversion with bypass.
In AC UPS, static switch shall be in both inverter and bypass path.
AC UPS shall comply with the requirements of Category C3 as per IEC 62040-2.
The maximum harmonic current distortion at AC UPS input shall comply with Table 2 of IEEE
Std 519™.
Acoustic noise of AC UPS at 1 m shall not exceed 75 dBA.
AC UPS maximum output frequency variation in unsynchronized conditions shall be ±0,1%.
AC UPS output voltage and frequency tolerances in all operating modes (normal energy mode,
storage energy mode and operation from bypass) shall be selected to match the requirements
of the loads to be fed.
AC UPS performance classification shall be VFI SS 111.
For AC UPS, DC earth condition shall be floating.
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For AC UPS, DC earth leakage monitoring shall be provided, with alarm on the UPS and on the
EMS.
AC UPS shall be interfaced with the EMS for monitoring purposes, as indicated in
20180.ENG.ELE.STD.
The information of the AC UPS to be shown in the EMS shall be as a minimum those listed in
IOGP S-701, § 8.4.2.5, § 8.4.3, § 8.4.4.2.
AC UPS distribution boards, if not integrated in the AC UPS, shall be interfaced with the EMS
with the same requirements as ASP, as indicated in 20180.ENG.ELE.STD.
AC UPS distribution board, if integrated in the AC UPS, shall as a minimum provide a common
alarm (cumulative of fault) to the EMS, plus the status and trip indication of the circuit
breakers upstream of the distribution bus bars.
AC UPS distribution board shall comply with IOGP S-560, both if integral to the UPS or
separated from it.
AC UPS distribution board shall comply with requirements of the present document for UPS
distribution board, both if integral to the UPS or separated from it.
If the AC UPS distribution board is not integral to the AC UPS, it shall be positioned in the
same room and as close as possible to it.
AC UPS distribution boards shall comply with COMPANY form MOD.ELE.LVS.001.
Maximum height of the AC UPS shall be 2,5 m.
If redundant AC UPS configuration is used (i.e. UPS of type “B” or “C” according to
28882.ENG.ELE.STD, or UPS type "D"), it shall be possible to replace components of a AC UPS
unit keeping the other AC UPS unit part of the redundant AC UPS configuration in service,
without risk of accidental contact with live parts.
Live parts of a redundant AC UPS that remain in service when one UPS unit is de-energized
shall be protected with barriers of at least IP2X with respect to an operator that is working on
the de-energized AC UPS unit.
The maintenance bypass switch and isolation transformer of AC UPS shall be mounted
separately in an adjacent compartment.
AC UPS cooling fans shall be replaceable while the AC UPS remains in service.
Fuses shall be permitted in AC UPS only for the protection of VTs, for the protection of
measuring instruments, for the protection of semiconductor devices or where shown in
28882.ENG.ELE.STD.
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AC UPS shall be provided with on-line battery capacity testing, to discharge the battery into
the load.
With batteries at the discharge minimum voltage, the AC UPS shall allow the recharge of the
battery to at least 80% capacity in a period of maximum 10 hours.
The AC UPS shall allow a black start, delivering power to the users at the rated output with
only the batteries as power source, with exception of AC UPS with SMC batteries.
If AC UPS with SMC batteries is used, an alternative method for black start shall be provided.
An alternative method for black start with respect to AC UPS with SMC batteries shall consist in
a UPS with batteries different from SMC or in an emergency diesel generator.
Emergency diesel generator used for black start in case of presence of AC UPS with SMC batteries
shall be capable of performing the warm-up and charge of the batteries and of feeding the UPS
loads at the same time.
The inverter section of the AC UPS shall deliver the short circuit current necessary to operate
the downstream protections in case of fault on an outgoing circuit.
If the AC UPS has two or more inverters to be operated in parallel, alarm of inverters not
synchronized shall be shown on the UPS front by means of HMI or LED signaling lights.
If the AC UPS has two or more inverters to be operated in parallel, alarm of inverters not
synchronized shall be raised to the EMS.
Remote manual reset of trip functions of the AC UPS, if foreseen, shall be performed from the
EMS.
Inverter of AC UPS shall be able to operate even if the batteries are disconnected and the
power is fed only by the relevant rectifier.
If there are motors among the loads of the AC UPS, the AC UPS motor starting capability shall
be verified in all possible operating configurations.
If the AC UPS is not capable of starting a motor, adjustable speed electrical power drive
system shall be provided for starting and integrated in the AC UPS distribution board.
Temporized disconnection of AC UPS loads with different autonomy times shall be as shown in
28882.ENG.ELE.STD.
Coordination and selectivity of protections in distribution downstream of AC UPS shall be
guaranteed in such a way that a fault on a single outgoing circuit does not compromise the
power supply to other feeders.
Baseframe, lift pad eyes and accessories for AC UPS installation shall be provided.
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For AC UPS rated more than 5 kVA, the incomer shall be three phase.
For AC UPS rated more than 120 kVA, the output shall be three phase.
Inspection and testing activities on AC UPS shall comply with CAS “B” of IOGP S-701Q as a
minimum.
The inverter outputs of AC UPS of type “D” shall be synchronized, if not used with distribution
section of type “2” according to 28882.ENG.ELE.STD.
2.8.6.4 DC Uninterruptible Power Supply System
DC UPS shall comply with IOGP S-702 “Supplementary Specification to IEC 62040-5-3 DC
Uninterruptible Power Systems (UPS)”.
DC UPS shall be suitable for ambient with pollution degree 3 as per IEC 62477-1.
Battery configuration of DC UPS without SMC batteries shall be 2x100%.
Battery configuration of DC UPS with SMC batteries shall be 2x100% or 1x100%.
The configuration of DC UPS without SMC batteries shall be parallel redundant.
The configuration of DC UPS with SMC batteries shall be parallel redundant or single.
Single DC UPS shall have redundant transformers (2x100%), redundant rectifiers (2x100%),
redundant DC/DC converters (2x100%) and non-redundant battery (1x100%).
Single DC UPS shall have one additional battery module with respect to the required autonomy.
DC UPS units part of a parallel redundant configuration shall be fed from different emergency
busbars.
Redundant DC UPS rectifiers shall be fed from different emergency busbars.
Configuration of DC UPS without SMC batteries shall be simplified dual DC UPS with common
output bus (Figure A.3 of IOGP S-702).
DC UPS topology shall be series converter connect.
DC UPS shall comply with the requirements of Category C3 as per IEC 62040-2.
Acoustic noise of DC UPS at 1 m shall not exceed 75 dBA.
The maximum harmonic current distortion at DC UPS input shall comply with Table 2 of IEEE
Std 519™.
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For DC UPS rated more than 5 kVA, the incomer shall be three phase.
DC UPS performance classification shall be NN.
DC UPS output voltage in all operating modes (normal energy mode, storage energy mode)
shall be selected in order to match the requirements of the loads to be fed.
For DC UPS, DC earth condition shall be floating.
For DC UPS, DC earth leakage monitoring shall be provided, with alarm on the UPS and on the
EMS.
DC UPS shall be interfaced with the EMS for monitoring purposes, as indicated in
20180.ENG.ELE.STD.
The information of the DC UPS to be shown in the EMS shall be as a minimum those listed in
IOGP S-702, § 8.2.2.5, § 8.2.3, § 8.2.4.2.
DC UPS distribution boards, if not integrated in the DC UPS, shall be interfaced with the EMS
with the same requirements as ASP, as indicated in 20180.ENG.ELE.STD.
DC UPS distribution board, if integrated in the DC UPS, shall as a minimum provide a common
alarm (cumulative of fault) to the EMS, plus the status and trip indication of the circuit
breakers upstream of the distribution bus bars.
DC UPS distribution board shall comply with IOGP S-560, both if integral to the UPS or
separated from it.
DC UPS distribution board shall comply with requirements of the present document for UPS
distribution board, both if integral to the UPS or separated from it.
If the DC UPS distribution board is not integral to the DC UPS, it shall be positioned in the
same room and as close as possible to it.
DC UPS distribution boards shall comply with COMPANY form MOD.ELE.LVS.001.
It shall be possible to replace components of a DC UPS unit keeping the other DC UPS unit part
of the parallel redundant DC UPS configuration in service, without risk of accidental contact
with live parts.
Live parts of a parallel redundant DC UPS that remain in service when one DC UPS unit is deenergized shall be protected with barriers of at least IP2X with respect to an operator that is
working on the de-energized DC UPS unit.
It shall be possible to replace redundant rectifiers, DC/DC converters and transformers of single
DC UPS units keeping the DC UPS unit in service, without risk of accidental contact with live
parts.
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Live parts of single DC UPS that remain in service while a redundant rectifier, DC/DC converter
or transformers is being replaced shall be protected with barriers of at least IP2X with respect
to an operator that is working on the de-energized DC UPS part.
DC UPS cooling fans shall be replaceable while the DC UPS remains in service.
Maximum height of the DC UPS shall be 2,5 m.
Fuses shall be permitted in DC UPS only for the protection of semiconductor devices,
measuring instruments and relays.
DC UPS shall be provided with on-line battery capacity testing, to discharge the battery into
the load.
With batteries at the discharge minimum voltage, the DC UPS shall allow the recharge of the
battery to at least 80% capacity in a period of maximum 10 hours.
If not dedicated to feed the auxiliaries of non-emergency packages and if not with SMC
batteries, the DC UPS shall allow a black start, delivering power to the users at the rated
output with only the batteries as power source.
If DC UPS with SMC batteries is used, an alternative method for black start shall be provided.
An alternative method for black start with respect to DC UPS with SMC batteries shall consist in
a UPS with batteries different from SMC or in an emergency diesel generator.
Emergency diesel generator used for black start in case of presence of DC UPS with SMC batteries
shall be capable of performing the warm-up and charge of the batteries and of feeding the UPS
loads at the same time.
Remote manual reset of trip functions of the DC UPS, if foreseen, shall be performed from the
EMS.
The short circuit capability of the DC UPS shall be sufficient to operate the downstream
protections in case of fault on an outgoing circuit.
DC UPS shall be able to operate even if the batteries are disconnected and the power is fed
only by the relevant rectifier.
Coordination and selectivity of protections in distribution downstream of DC UPS shall be
guaranteed in such a way that a fault on a single outgoing circuit does not compromise the
power supply to other feeders.
Temporized disconnection of DC UPS loads with different autonomy times shall be foreseen.
Baseframe, lift pad eyes and accessories for DC UPS installation shall be provided.
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Inspection and testing activities on DC UPS shall comply with CAS “B” of IOGP S-702Q as a
minimum.
2.8.6.5 Battery isolator box (AC and DC UPS)
Batteries shall be connected to AC UPS though battery isolator box.
Batteries shall be connected to DC UPS though battery isolator box.
Battery isolator box shall be in AISI 316L or GRP.
The battery isolator included in battery isolator box shall be a MCCB.
Battery isolator box shall be certified EPL “Gb”.
Battery isolator box, if installed outdoors, shall have a minimum degree of protection of IP55.
Battery isolator box shall comply with 20056.ENG.ELE.STD.
In offshore facilities, the battery isolator box shall be provided with undervoltage coil controlled
by SIS to open the circuit breaker.
In offshore facilities, the battery isolator box of AC UPS shall be provided with black start
override, with exception of AC UPS with SMC batteries.
In offshore facilities, the battery isolator box of DC UPS shall be provided with black start override
only if the DC UPS is used for black start.
In onshore facilities, the circuit breaker of the battery isolator box shall not be controlled by
SIS.
2.8.6.6 Selection of UPS autonomy (AC and DC UPS)
UPS autonomy shall comply with opi hse 023 eni spa “Safety & Environmental Minimum Design
Requirements”.
2.8.7
Storage batteries
Batteries other than SMC batteries shall comply with IOGP S-740 “Specification for batteries
(IEC)”.
Battery technology shall be nickel-cadmium partial gas recombination, valve-regulated lead-acid
– AGM, valve-regulated lead-acid – gel or SMC.
SMC batteries shall not be used for gas or diesel engine starting.
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Nickel-cadmium partial gas recombination batteries shall comply with IEC 62259.
Valve-regulated lead-acid – AGM batteries shall comply with IEC 60896-22.
Valve-regulated lead-acid – gel batteries shall comply with IEC 60896-22.
SMC batteries shall comply with IEC 62984 series.
Service life of Ni-Cd batteries that are regularly under floating charge conditions, at the design
ambient temperature of the room in which they are installed, shall not be less than 20 years.
Service life of VRLA AGM batteries that are regularly under floating charge conditions, at the
design ambient temperature of the room in which they are installed, shall not be less than 12
years.
Service life of VRLA gel batteries that are regularly under floating charge conditions, at the
design ambient temperature of the room in which they are installed, shall not be less than 15
years.
Service life of SMC batteries that are regularly under floating charge conditions, at the design
ambient temperature of the room in which they are installed, shall not be less than 20 years.
Battery cells shall not require refilling during their service life.
The number of battery cells for UPS application shall be chosen in such a way that at the end
of autonomy time with the required load profile the DC voltage at UPS terminals is such as to
guarantee that the output voltage of the UPS is within required limits.
Value of rated voltage of single battery cells shall be provided.
Value of gassing voltage of single cells shall be provided for batteries other than SMC.
Value of minimum voltage at end of discharge at 20°C ambient temperature shall be provided
for single battery cells.
The material of the battery cell containers for onshore installation shall comply with UL 94
class HB, with exception of SMC batteries.
The material of the battery cell containers for offshore installation shall comply with UL 94
class V0, with exception of SMC batteries.
Batteries for onshore facilities shall be installed in dedicated battery rooms, with exception of
engine starting batteries located on or close to the engine skid and of SMC batteries.
Batteries for offshore manned facilities shall be installed in dedicated battery rooms, with
exception of engine starting batteries located on or close to the engine skid and of SMC
batteries.
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The required autonomy time of batteries shall be verified in the whole range of ambient
temperatures, including the case in which HVAC is not operational due to shutdown of main
and emergency power systems.
Battery cell containers shall bear the two polarity signs clearly visible near the respective
poles.
The container of valve regulated batteries shall be provided with outlet valve, normally closed
to avoid oxygen entrance from external ambient.
Connecting bolts with anti-loosening device shall be used for connection between battery cells.
Welded connections between battery cells shall be prohibited.
Electrical connections between battery cells, battery modules, tiers and racks shall be insulated
or protected with covers to realize a protection against accidental contact with live parts of at
least IP 2X.
Battery cells and battery modules terminals shall be insulated or protected with covers to realize
a protection against accidental contact with live parts of at least IP 2X.
Tools required in IOGP S-740, subclause 9.2.1 shall be provided for batteries other than SMC.
Commissioning charge of UPS batteries shall be possible with the UPS or with a portable
external battery charger, with exception of SMC batteries.
Commissioning charge of generator starting batteries shall be possible with the battery charger
of the generator package or with a portable external battery charger.
If necessary for commissioning charge of batteries, a portable external battery charger shall be
provided.
If the weight of a single cell or module exceeds 25 kg, a battery lift or battery removal tool
shall be provided.
A lifting tool for removing multiple vertical installations of SMC batteries shall be provided.
Batteries for UPS installed in battery room shall be on battery rack.
Battery rack shall be solidly fixed to the floor to avoid the falling of batteries.
Battery rack shall have a maximum of three tiers, with exception of racks for SMC batteries.
Maximum height of battery rack, measured from the top of battery on the top tier to the floor,
shall be 1800 mm.
Material for battery rack shall be chemical resistant.
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In FPSO and floaters, the batteries shall not spill electrolyte in the conditions indicated in IEC
61892-5 as the limits of inclination in which emergency machinery are required to operate.
For FPSO and floaters, the battery rack shall be anti-seismic.
For FPSO and floaters, the batteries and the rack shall not fall in the conditions indicated in IEC
61892-5 as the limits of inclination in which emergency machinery are required to operate.
Close to each battery rack a sectioning device (switch-disconnector or circuit breaker) shall be
provided, to isolate the rack for maintenance purposes.
Inspection and testing activities on batteries shall comply with CAS “D” of IOGP S-740Q as a
minimum, with exception of SMC batteries.
SMC battery tests shall be as per IEC 62984-3.
2.8.8
Rotating electrical machines
2.8.8.1 General
Rotating electrical machines shall comply with IEC 60034 series.
2.8.8.2 MV induction motors
MV induction motors shall comply with IOGP S-704 “Supplementary Specification to IEC
60034-1 High Voltage Three-phase Cage Induction Motors”.
MV induction motors, if installed indoors, shall have a degree of protection of IP44 as a
minimum.
Star point terminal box shall be provided for MV induction motors with differential protection.
If report from test on identical motor is not available, the test of noise level at no load shall be
performed for MV induction motor.
Lateral analysis shall be performed for MV induction motors rated over 400 kW.
Lateral analysis shall be performed for MV induction converter-fed motors.
Torsional analysis shall be performed for MV induction motors rated over 400 kW.
Torsional analysis shall be performed for MV induction converter-fed motors.
MV induction motors shall be provided with the sensors indicated in 28906.ENG.MEC.STD.
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For MV induction motors, space heaters shall be provided for motor windings and for line
conductor terminal box.
MV induction motors shall have at least two ISO metric thread earthing terminals fitted
externally on the frame.
MV induction motor auxiliary fans and pumps, if driven by independent motor, shall have a
N+1 sparing philosophy.
In case of trip of an auxiliary fan or pump of MV induction motor, an alarm shall be raised to a
manned location.
With reference to IOGP S-704, subclause 15.2, type test certification for use with converter
shall always be required for MV induction motors with type of protection “e”, according to IEC
60079-14.
Cooling methods based on water shall be permitted for MV induction motors only in offshore
and for ratings of 2 MW and above.
Inspection and testing activities on MV induction motors shall comply with CAS “C” of IOGP S704Q as a minimum.
2.8.8.3 LV induction motors
LV induction motors shall comply with IOGP S-703 “Supplementary Specification to IEC 600341 Low Voltage Three Phase Cage Induction Motors”.
Space heaters shall be provided for LV induction motors.
LV induction motors, if installed indoors, shall have a degree of protection of IP44 as a
minimum.
With reference to IOGP S-703, subclause 15.3, type test certification for use with converter
shall always be required for motors with type of protection “e”, according to IEC 60079-14.
Inspection and testing activities on LV induction motors shall comply with CAS “C” of IOGP S703Q as a minimum.
2.8.8.4 Synchronous machines
Synchronous machines shall comply with COMPANY standard 20168.ENG.ELE.STD.
The stator and field windings of synchronous machines shall have insulation in class F or H
with temperature rise limited to class B.
For exterior locations, synchronous machines shall have a degree of protection not lower than
IP55.
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For interior locations, synchronous machines shall have a degree of protection not lower than
IP44.
Space heaters shall be provided for synchronous machines.
Terminal boxes containing space heater terminals shall be fitted with a warning label indicating
that the terminals may be live when the synchronous machine is de-energized.
MV synchronous machines auxiliary fans and pumps, if driven by independent motor, shall
have a N+1 sparing philosophy.
In case of trip of an auxiliary fan or pump of MV synchronous machine, an alarm shall be
raised to a manned location.
MV synchronous machines shall have sensors in compliance with COMPANY Standard
28906.ENG.MEC.STD.
Thermal detectors for MV synchronous machines windings and bearings shall be of platinum of
100 Ω at 0°C (PT100).
MV synchronous machines shall have at least two ISO metric thread earthing terminals fitted
externally on the frame.
Lateral analysis shall be performed for MV synchronous machines rated over 400 kW.
Lateral analysis shall be performed for MV converter-fed synchronous motors.
Torsional analysis shall be performed for MV synchronous machines rated over 400 kW.
Torsional analysis shall be performed for MV converter-fed synchronous motors.
Synchronous generators driven by combustion turbine or by steam turbine and having a rating
not lower than 10 MVA shall comply with IEC 60034-3.
Reciprocating engine driven synchronous generators shall comply with IEC 60034-22.
The excitation of synchronous generators shall be brushless.
MV synchronous generator line and neutral terminal boxes shall be provided with the CTs and
VTs necessary for measurements, protections, AVR and synchronization.
Synchronous generators shall be designed to sustain without failure a sudden short circuit at
their terminals, for the time necessary for the intervention of the protections.
The short circuit withstand test shall not be performed on synchronous generators.
Synchronous generators shall be capable to withstand the maximum earth fault current that
can happen, for the time necessary for the intervention of the protections, and without
damage to their components.
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Synchronous generators shall be capable of sustaining a minimum short circuit current value,
and for a determined minimum time, to allow the intervention of the protections.
Each MV synchronous generator shall be provided with a generator control panel for control of
synchronization, excitation control, AVR, protections and measurement indications.
LV synchronous generators shall be provided with a control panel.
Generator control panels shall comply with IEC 60204-1.
MV synchronous generator control panel shall provide measuring indications of three phase
currents, three phase voltages, frequency, power factor, active power, reactive power, active
energy, reactive energy of the generator output, and of exciter voltage and current.
Synchronous generator control panels shall be provided with facilities for manual and
automatic synchronization and for connection on dead bus of the generator.
It shall be possible to select the type of synchronization (manual or automatic) from the
synchronous generator control panel.
In manual synchronization mode, it shall be possible to manually raise and lower the voltage
and the frequency of the synchronous generator.
Synchronous generator synchronization facilities shall take into account the closing time of the
circuit breaker used to parallel the generator.
In both manual and automatic synchronization mode, the connection to an unsynchronized
busbar shall be inhibited, with exception of connection on dead bus.
If the generating set is started in automatic, the synchronization shall be automatic even if the
selector is in the position of manual synchronization.
MV synchronous generators shall be provided with protections against overload and short
circuit.
The protections of a MV synchronous generator shall be capable to open the downstream
circuit breaker and to de-excite the generator in case of short-circuit in the generator itself or
in the connection between the generator and the downstream circuit breaker.
The protections of a MV synchronous generator shall remain effective also in case of voltage or
frequency deviations from rated values.
MV synchronous generators shall be protected against loss of field (F40), negative sequence
(F46), undervoltage (F27), overvoltage (F59), under and over frequency (F81), reverse power
(F32) and with differential protection (F87G).
The reverse power protection of a MV synchronous generator shall be capable to operate with
a voltage drop up to 50% at generator terminals.
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In case of earth fault on a MV synchronous generator circuit, the protections shall be capable
to discriminate the faulty generator, avoiding the disconnection of healthy power sources
operated in parallel.
MV synchronous generators shall be protected against excessive temperatures in the windings
and in the bearings, with alarm and trip thresholds.
MV synchronous generators shall be protected against excessive vibrations.
MV synchronous generators shall be protected against earth fault on the rotor circuit, with
alarm and trip thresholds.
The recommended protections and settings of MV generator SUPPLIER shall be provided.
2.8.9
Cables, wires and accessories
2.8.9.1 General
Connections between equipment shall be realized by means of cables, bus ducts or cable bus.
Bus duct and cable bus shall be permitted only for connections between generator and step-up
transformer, and between transformer and switchgear, if the rating is 3000 A or higher.
Cables within the same facility shall be continuous, without joints.
Intermediate junction boxes between switchgear outgoing feeder and user shall be permitted
only for lighting and small power circuits.
Cables installed in cable ladder shall be fixed to the ladder rungs with cable cleats certified for
the upstream prospective short-circuit current.
Cable cleats for single core cables shall be trefoil type.
Each trefoil cable cleat used for single core cables shall accommodate one core per phase.
2.8.9.2 General requirements for cables
Electrical control/command cables shall comply with the same requirements of power cables.
Onshore power cables for installation outside EU shall comply with IEC 60502-1, IEC 60502-2
or IEC 60840, depending on voltage.
Power cables for installation outside EU shall be low smoke, halogen free and flame retardant,
according to IEC 61034-1, IEC 61034-2, IEC 60754-1, IEC 60754-2, IEC 60684-2 and IEC
60332-3-22.
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NOTE: even if indicated in IEC 60502-1 and IEC 60502-2, the insulating compound “PVC/A”
and “PVC/B” is not permitted.
Offshore power cables for installation outside EU shall comply with IEC 61892-4.
Onshore cables to be routed where there is risk of deposits or dripping of liquid hydrocarbons
shall have been qualified according to the testing criteria indicated in IEC 60502-1:2021, Table
22, or in IEC 60502-2:2014, Table 23, depending on cable voltage.
Offshore cables to be routed where there is risk of deposits or dripping of liquid hydrocarbons
shall have a sheath complying with the test results of IEC 60092-360:2021, Table 6, with
reference to the test method of IEC 60811-404.
Cables shall be fire resistant for circuits related to power and control of firefighting system, fire
and gas detection system, emergency escape lighting without incorporated battery, obstruction
lights, radio communication, navigation aids, helideck lights, helideck status lights, boat
landing status lights and for other safety applications indicated in COMPANY Standard
28045.ENG.STA.PRG.
Cables feeding protections or switchgear controls from UPS shall be fire resistant if routed
outside of the electrical room building.
Fire resistant cables for installation outside EU shall comply with IEC 60331 series.
Fire resistant cables for installation outside EU shall also be low smoke and halogen free,
according to IEC 61034-1, IEC 61034-2, IEC 60754-1, IEC 60754-2, IEC 60684-2.
Fire resistant cables for offshore installation outside EU shall comply with type test
requirements of IEC 60092-350.
For indoor distribution to lighting and small power users, cable conductors of class 5 or class 6
shall be used, according to IEC 60228.
Onshore cables used in systems with automatic disconnection of power supply at first earth
fault shall be of category “B”, according to IEC 60502-1 and IEC 60502-2.
Onshore cables used in systems without automatic disconnection of power supply at first earth
fault shall be of category “C”, according to IEC 60502-1 and IEC 60502-2.
Offshore cables used in systems with automatic disconnection of power supply at first earth
fault shall be of category “B”, according to IEC 61892-4.
Offshore cables used in systems without automatic disconnection of power supply at first earth
fault shall be of category “C”, according to IEC 61892-4.
Conductors of offshore cables shall not be in aluminium.
Offshore cables outer sheath compounds shall be SHF 1 or SHF 2 according to IEC 60092-360.
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The identification of conductors of cables, excluding LV cables installed in Italy, shall comply
with IEC 60445.
The identification of conductors of cables in accordance with IEC 60445 shall be by colours.
NOTE: the identification by alphanumeric notation, described in IEC 60445, is not allowed.
The identification of conductors of LV cables installed in Italy shall comply with CEI UNEL
00722.
The colour of outer sheath of LV power cables for installation outside Italy, excluding fire
resistant cables and control/command cables, shall be black or grey, with only one colour in a
facility.
The colour of outer sheath of control/command cables for installation outside Italy shall be
black, excluding fire resistant cables.
The colour of outer sheath of MV cables for installation outside Italy shall be red, white or
violet, with different colours for different voltage levels and with only one colour for each
voltage level in a facility.
The colour of outer sheath of cables installed in Italy shall comply with CEI UNEL 00721.
Fire resistant cables for installation outside Italy shall have a color of outer sheath different
from the colours of other cables (e.g. orange).
Routine tests and sample tests of cables shall be performed as per referenced standards, for
the cables in their scope of applicability.
Tests after installation shall be performed on offshore cables as per Annex A of IEC 60092354:2020, for cables in its scope of applicability.
Tests after installation shall be performed on offshore cables in the scope of applicability of IEC
60092-353 as per recommendations of VENDOR.
Tests after installation shall be performed on onshore cables as per IEC 60502-1, IEC 60502-2,
IEC 60840.
DC voltage test of cable insulation shall not be permitted for cables rated more than U0/U
1,8/3 kV.
2.8.9.3 Cable sizing criteria
LV onshore cable sizing shall comply with IEC 60364-5-52.
Offshore cable sizing shall comply with IEC 61892-4.
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Cable sizing shall be performed to contain voltage drops within permitted limits, in steadystate and transient conditions.
Cable sizing shall be performed to contain temperatures within the limits of the insulation,
during normal operation.
Cable sizing shall be performed to contain temperatures within the limits of the insulation,
during overload and short-circuit, for the time necessary for the intervention of the
protections.
Short-circuit current used for cable sizing for containment of temperatures within the limits of
the insulation shall be the maximum prospective short-circuit current at the switchgear feeding
the cable.
Cable sizing shall be performed to allow the intervention of the protections even in case of
minimum short-circuit conditions at the end of the line.
The normal operation current to be considered for the sizing of cables connecting generators
shall be the highest steady-state current of the generator in the range of operating site
conditions.
The normal operation current to be considered for the sizing of cables connecting transformers,
motors and heaters shall be the rated current of the equipment.
The normal operation current to be considered for the sizing of cables connecting a switchgear
to a sub-distribution switchgear without interposed transformer shall be the rated current of
the sub-distribution switchgear.
The normal operation current to be considered for the sizing of cables between switchgear and
socket junction box shall be the rated current of the farthest socket, plus the rated current of
the other sockets multiplied by the factor 1/n+0,1, where “n” is the total number of sockets
fed by the same junction box.
The normal operation current to be considered for the sizing of the cable between junction box
and socket shall be the socket rated current.
2.8.9.4 Battery cables
The normal operation current to be considered for sizing of the cables between battery and
UPS shall be the highest between maximum charging current (e.g. boost charge current, if
available) and the maximum current required by the UPS when operated in stored energy
mode, considering the overload capability.
Sizing of cables between battery and UPS shall consider the maximum fault current available.
Battery cables shall be single core.
Battery cables shall be fire resistant according to IEC 60331.
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Resistance to fire of battery cables shall be for 30 minutes or more, according to IEC 60331.
Battery cables external sheath shall be resistant to chemicals and acids.
Battery cables shall be non-armoured if routed within the same building.
2.8.9.5 Control/command cables
For control/command cables, the capacitance of cable and voltage drop shall be considered to
avoid relay malfunction.
2.8.9.6 Mechanical protection of cables
Cables in hazardous areas shall be armoured, with exception of battery cables in battery room.
Outdoor cables, if wholly installed in non-hazardous areas, shall be armoured or provided with
mechanical protection, consisting in cable tray with cover or conduit, up to equipment terminal
box entry.
If a cable route has a section in hazardous area, precautions shall be taken to avoid the spread
of hazardous substances in a non-hazardous area.
NOTE: examples of precautions to avoid the spread of hazardous substances from hazardous
to non-hazardous areas are: cable trench with cover filled with sand, or sealing of cableway in
duct.
Armour of single core cables shall be in non-magnetic material.
Armour of cables connecting adjustable speed electrical power drive systems and thyristor
controlled panels shall comply with VENDOR recommendations.
2.8.9.7 Cables screen
MV cables shall be provided with screen.
Control/command cables shall be provided with screen.
LV cables connecting adjustable speed electrical power drive systems and thyristor controlled
panels shall be provided with screen if required in VENDOR recommendations.
2.8.9.8 Minimum and maximum conductor section
The choice of cable conductor sections shall consider the bending radius of cables in respect to
the available cable installation space.
MV onshore three-core cables shall have a minimum conductor section of 25 mm2.
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MV onshore three-core cables shall have a maximum conductor section of 240 mm2.
MV onshore single core cables shall have a minimum conductor section of 240 mm2.
MV onshore single core cables shall have a maximum conductor section of 630 mm2.
MV offshore three-core cables shall have a minimum conductor section of 25 mm2.
MV offshore three-core cables shall have a maximum conductor section of 120 mm2.
MV offshore single core cables shall have a minimum conductor section of 120 mm2.
MV offshore single core cables shall have a maximum conductor section of 300 mm2.
Power supply to LV motor main terminals shall be with single core or four core cables.
LV four-core cable power distribution, excluding lighting, shall have a minimum conductor
section of 4 mm2.
LV four-core cable power distribution, excluding lighting, shall have a maximum conductor
section of 240 mm2.
LV five-core cable power distribution, excluding lighting, shall have a minimum conductor
section of 4 mm2.
LV five-core cable power distribution, excluding lighting, shall have a maximum conductor
section of 185 mm2.
LV single core cables, excluding connection between battery and UPS, shall have a minimum
conductor section of 240 mm2.
LV onshore single core cables, excluding connection between battery and UPS, shall have a
maximum conductor section of 630 mm2.
LV offshore single core cables shall have a maximum conductor section of 300 mm2.
LV cables for lighting shall be multi-core.
LV cables for lighting shall have a minimum conductor section of 2,5 mm2.
LV cables for lighting shall have a maximum conductor section of 95 mm2.
LV single core power cables between batteries and UPS shall have a minimum conductor
section of 25 mm2.
LV single core power cables between batteries and UPS shall have a maximum conductor
section of 300 mm2.
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Logical wiring among boards in electrical room shall be multi-core.
Logical wiring among boards in electrical room, excluding Ethernet cables, shall have a
minimum conductor section of 1,5 mm2.
Cables for electrical control and command towards the field shall be multi-core.
Cables for electrical control and command towards the field shall have a minimum section of
2,5 mm2.
Analog and digital signal cables shall be multi-core.
Analog and digital signal cables among panels in electrical room and the control system shall
have a minimum section of 1,5 mm2.
To avoid using conductor sections higher than permitted ones, cables is parallel shall be used.
Cables in parallel shall have the same impedance, the same length and the same section so
that the current is equally distributed on each cable.
Single core buried cables in trefoil formation shall be fixed together with metal clamps.
2.8.9.9 General requirements for CPR cables (applicable for EU projects)
Cables to be installed in EU shall be specified according to the Regulation 305/2011 of the
European Parliament and of the Council and its interpretation through National Laws and
Committee.
Cables to be installed in EU and not required to be fire resistant shall have characteristics not
lower than class Cca-s1b, d1, a1 according to EN 13501-6.
Cables to be installed in EU and required to be fire resistant shall have characteristics not
lower than class B2ca – s1a, d1, a1 according to EN 13501-6.
Cables to be installed in Italy shall comply with Dlgs 106/17.
Cables to be installed in Italy and not required to be fire resistant shall be low smoke, halogen
free and flame retardant, with class Cca-s1b, d1, a1 according to UNI EN 13501-6 and CEI
UNEL 35016.
Cables to be installed in Italy and required to be fire resistant shall be low smoke, halogen free
and fire resistant, with class B2ca – s1a, d1, a1 according to UNI EN 13501-6 and CEI UNEL
35016.
For CPR cables, tests and inspections shall be according to EN 50399, EN 60332-1-2, EN
61034-2, EN 60754-2.
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Fire resistant cables installed in EU but outside Italy shall comply with EN 50200 and EN IEC
60331-1.
For fire resistant cables installed in Italy, tests and inspections shall be according to CEI EN
50200, CEI EN IEC 60331-1, CEI 20-45 and CEI 20-45 V2.
2.8.10 Overhead transmission lines
Overhead transmission lines shall be permitted only to connect the plant with remote areas,
outside of its boundaries.
Overhead transmission lines shall comply with the requirements and recommendations of EN
50341-1.
Limits of exposure to electric and magnetic fields shall be as per national normatives and
regulations.
If limits of exposure to electric and magnetic fields are not defined in national normatives or
regulations, the limits and recommendations indicated in the Directive 2013/35/EU of the
European Parliament and of the Council shall be applicable.
To provide protection against atmospheric discharge on the overhead transmission lines, surge
arresters shall be foreseen after the gantry structure (e.g. primary side of plant incoming
transformer).
Overhead transmission lines shall be protected against lightning by means of earth wires.
Earth wires for the protection of overhead transmission lines shall be sized according with the
results of calculations considering the value of expected lightning current.
Shielding of the overhead transmission line by means of earth wires shall be demonstrated by
means of calculations.
Wooden supports shall not be used for overhead transmission lines.
2.8.11 Surface treatments of electrical equipment
Painting colours of electrical equipment for offshore and coastal areas shall comply with
COMPANY Standard 29000.ENG.CPI.STD, Appendix “A”, Table “A-2”.
Painting colours of onshore electrical equipment shall comply with COMPANY Standard
29001.ENG.CPI.STD, Appendix “A”, Table “A-2”.
Surface treatments of electrical equipment for offshore and coastal areas shall comply with
COMPANY Standard 29000.ENG.CPI.STD.
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Surface treatments of onshore electrical equipment shall comply with COMPANY Standard
29001.ENG.CPI.STD.
2.8.12 Neutral earthing resistors
Neutral earthing resistors and related testing activities shall comply with IEEE Std C57.32™,
including the amendment issued in 2020, with exception of insulation levels and of test
voltages for applied voltage tests.
For neutral earthing resistors, insulation levels and test voltages for applied voltage tests shall
be chosen according to highest voltages for equipment and standard rated short duration
power-frequency withstand voltages indicated in IEC 60071-1.
Rated time of neutral earthing resistors shall be 10 seconds.
Neutral earthing resistors shall be made of stainless steel.
Neutral earthing resistors shall be provided with removable links.
A contactor, circuit breaker or switch inside an enclosure shall be provided if it is necessary to
have the possibility to disconnect the neutral earthing resistor.
NOTE: the cases in which it is required to have the possibility to disconnect the neutral
earthing resistors are indicated in 2.7.5.1.
The enclosure for the contactor, circuit breaker or switch of a neutral earthing resistor shall
have the same requirements of degree of protection, access protection and material as the
enclosure of the neutral earthing resistor, if different from it.
The contactor, circuit breaker or switch of a neutral earthing resistor shall be capable to be
controlled and monitored by a remote logic.
NOTE: the logic for neutral earthing resistors is described in 2.7.5.1.
Neutral earthing resistors installed indoors, in rooms enclosed on all sides, shall be housed in a
metallic enclosure providing a degree of protection of IP23 as a minimum.
Neutral earthing resistors installed in a room opened on one side to the outdoors, by means of
grating or louvers, shall be housed in a metallic enclosure providing a degree of protection of
IP44 as a minimum.
Neutral earthing resistors installed outdoors shall be housed in a metallic enclosure providing a
degree of protection of IP55 as a minimum.
In offshore and coastal areas, the enclosures of neutral earthing resistors shall be made of
AISI 316L.
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In onshore non-coastal areas, the enclosures of neutral earthing resistors shall be in AISI 316L
or galvanized steel.
Cable entrances in enclosure of neutral earthing resistor shall be made of non-magnetic
material.
External parts of neutral earthing resistor enclosure shall be provided with a warning indication
against burning hazard, as per opi hse 023 eni spa “Safety & Environmental Minimum Design
Requirements”.
A mechanical interlock shall permit access to potentially live parts of the neutral earthing
resistor only in case the resistor is de-energized, as well as the generator or transformer to
which it is connected.
A space heater controlled by thermostat or a self-regulating anti-condensation heater shall be
provided in the enclosure of the neutral earthing resistor.
Space heaters for neutral earthing resistor enclosure shall be protected on the feeding line with
MCBs or switch-disconnector-fuses located in the junction box.
Space heaters for neutral earthing resistor enclosures shall be protected to at least IP2X.
Space heaters for neutral earthing resistor enclosures shall be provided with a mechanical
guard if the surface temperature exceeds 60°C.
Neutral earthing resistor nameplates shall be engraved with writing on plates made of AISI
316L stainless steel.
Neutral earthing resistor nameplates shall be attached with AISI 316L fixings.
Junction boxes shall be provided for the connection of auxiliary circuits of neutral earthing
resistors.
Terminals remaining live when the neutral earthing resistor is de-energized shall be provided
with warning labels.
Current transformers for protection functions shall be provided for the neutral earthing
resistor.
Current transformers of neutral earthing resistors shall be installed inside the enclosure of the
neutral earthing resistor, upstream of the resistor.
Neutral earthing resistor current transformer wiring connected to external circuits shall have
shorting links located at the outgoing terminals.
Current transformers of neutral earthing resistors shall have the secondary windings connected
to earth by means of disconnecting link.
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Neutral earthing resistors shall be provided with lifting eyebolts and with accessories necessary
for installation and maintenance.
2.8.13 Electric process heaters
Electrical requirements for electric process heaters shall be as per IOGP S-723 “Specification
for Electric Process Heaters”.
Regarding the power and control assembly of electric process heaters, enclosures for LV
applications shall be arc resistant.
Inspection and testing activities on electric process heaters shall comply with CAS “C” of IOGP
S-723Q as a minimum.
2.8.14 Safe shutdown of machinery
Systems for safe shut down of turbines relying on electrical power shall be certified EPL “Gc”
as a minimum, regardless of location, with gas group determined according to potential
emission sources present in nearby hazardous areas.
Systems for safe shut down of turbines shall not rely on equipment not certified EPL “Gc” as a
minimum.
2.8.15 Adjustable Speed Electrical Power Drive Systems
2.8.15.1
General
Adjustable speed electrical power drive systems shall comply with IEC 61800 (all parts).
Adjustable speed electrical power drive systems outside of the scope of applicability of both
IOGP S-736 and IOGP S-747 shall not be used.
Circuit breakers installed downstream of the BDM/CDM shall be designed to interrupt the short
circuit current in the whole range of operating frequencies.
Circuit breakers and switchgear installed upstream of a BDM shall be designed taking into
account the fault currents that can happen in the BDM (e.g. for diode failure).
For adjustable speed electrical power drive systems, transformers installed upstream of the
converter shall be designed to withstand the effects of short circuit currents, also for faults
inside the converter.
In case of outdoor installation, the minimum protection degree of BDM/CDM enclosure shall be
IP55.
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Solutions with a single CDM feeding multiple motors shall not be permitted.
An input transformer part of a CDM shall not feed more than one BDM.
An output transformer part of a CDM shall not be fed from more than one BDM.
The maximum harmonic current distortion at BDM/CDM/PDS input shall comply with Table 2 of
IEEE Std 519™.
2.8.15.2
Adjustable Speed Electrical Power Drive Systems according to IOGP S747
The additional requirements of IOGP S-747 “Supplementary Specification to IEC 61800-2 Highvoltage AC Drive Systems” shall be applied for the BDM/CDM part of its scope of applicability.
Where the IOGP S-747 gives an alternative between the application of IEC standards and other
types of standards different from IEC or ISO, IEC standards shall be followed.
Where the IOGP S-747 gives an alternative between the application of IOGP standards and
other types of non-IEC standards, IOGP standards shall be followed.
BDM/CDM in the scope of applicability of IOGP S-747 shall have an enclosure with a minimum
degree of protection of IP31 for MV compartments.
For adjustable speed electrical power drive systems within the scope of applicability of IOGP S747, performance tests listed in Table 22 of IOGP S-747 shall be carried out on at least one
adjustable speed electrical power drive system of a group of identical systems, within the same
facility.
For adjustable speed electrical power drive systems part of the scope of applicability of IOGP
S-747, a screening study shall be performed to ensure that there are not risks of
subsynchronous torsional interactions due to torque-ripple excitation frequencies.
Rated arc fault currents of BDM/CDM in the scope of applicability of IOGP S-747 shall be higher
than maximum short circuit currents that can happen on the BDM/CDM.
For BDM/CDM enclosure part of the scope of applicability of IOGP S-747, arc flash detection
sensor shall be provided.
For BDM/CDM enclosure part of the scope of applicability of IOGP S-747, arc flash detection
sensor shall be light plus current type.
For BDM part of the scope of applicability of IOGP S-747, insulation of internal wiring shall be
low halogen and flame retardant with low smoke index.
For BDM/CDM part of the scope of applicability of IOGP S-747, emergency stop shall be on
drive control panel and with terminals for external stop input.
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BDM/CDM in the scope of applicability of IOGP S-747 shall be at least suitable for installation in
an ambient with pollution degree as indicated in IEC 61800-2:2021, Table 12, depending on
the conditions of installation.
Inspection and testing activities for adjustable speed electrical power drive systems in the
scope of applicability of IOGP S-747 shall comply with CAS “C” of IOGP S-747Q as a minimum.
2.8.15.3
Adjustable Speed Electrical Power Drive Systems according to IOGP S736
The additional requirements of IOGP S-736 “Supplementary Specification to IEC 61800-2 Lowvoltage AC Drives” shall be applied for the BDM/CDM in its scope of applicability.
BDM/CDM in the scope of applicability of IOGP S-736 shall have overvoltage category III as a
minimum, according to IEC 61800-5-1.
BDM/CDM in the scope of applicability of IOGP S-736 shall have an enclosure with a minimum
degree of protection of IP2X.
For BDM/CDM part of the scope of applicability of IOGP S-736, provision for remote stop from
a local motor control station shall be foreseen.
For BDM/CDM part of the scope of applicability of IOGP S-736, gland plates for the ingress of
single core cables shall be made of non-magnetic material.
Inspection and testing activities for adjustable speed electrical power drive systems in the
scope of applicability of IOGP S-736 shall comply with CAS “C” of IOGP S-736Q as a minimum.
Torsion analysis for PDS including LV motors shall be performed in the cases recommended in
IEC 61800-2:2021, 5.13.2.
2.8.16 Navigation & aeronautical aids system for offshore platforms and floaters
Aids to navigation for offshore facilities shall comply with COMPANY Standard
20174.ENG.ELE.STD.
Helideck lighting system for offshore facilities shall comply with COMPANY Standard
20174.ENG.ELE.STD.
Boat landing status lights for offshore facilities shall comply with COMPANY Standard
20174.ENG.ELE.STD.
2.8.17 Swivel and turret
Concerning the electrical parts of the swivel and turret, IEC 61892-2 shall be complied with,
including the recommendations included in Annex D of IEC 61892-2:2019.
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Electrical distribution through the swivel shall be designed in such a way that a failure of any
feeder passing through slip rings does not render any essential, emergency or safety service
unavailable.
New low voltage swivel shall be provided with spare slip rings sufficient for a minimum of two
feeders.
New medium voltage swivel shall be provided with spare slip rings sufficient for a minimum of
two feeders.
Rating of medium voltage spare slip rings shall be equal to the maximum rating of the slip
rings foreseen for the MV users.
Rating of low voltage spare slip rings shall be equal to the maximum rating of the slip rings
foreseen for the LV users.
2.8.18 Submarine cables
Submarine power cables and related accessories shall comply with IEC 63026, for the voltage
ranges and water depths therein indicated.
NOTE: this paragraph is applicable to submarine power cables connecting two surface facilities,
and does not cover umbilicals or feeding of subsea facilities.
For the purpose to choose submarine power cable rated voltages, the system shall be
considered to be of Category C as per IEC 63026.
Where a greater protection of the submarine power cable is required (e.g. in sea beds in
presence of rocks or reefs) an additional layer shall be applied to the armour, as explained in
subclause 5.8 of IEC 63026:2019.
As a minimum, the characteristics of submarine power cable listed in clause 6 of IEC
63026:2019 shall be provided.
Submarine power cables shall include the minimum possible number of joints.
Progressive numbering for the determination of the length, repeated at constant 1 m intervals
on the external sheath of the cable, shall be provided for submarine power cables.
If delivery drum is applied to a submarine power cable, the extremities of each cable delivery
length shall be sealed and fixed to the drum.
If delivery drum is applied to a submarine power cable, the extremities of each cable delivery
length shall be accessible for checks and tests without need of unwinding the cable.
If delivery drum is applied to a submarine power cable, the internal and external flanges of the
drums shall be provided with metallic label indicating at least data at points a) and b) of clause
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6 of IEC 63026:2019, number of cores, conductor cross section, cable identification code
number, drum identification number, length of cable on the drum, total weight of drum and
cable.
As a minimum, optical fibre shall be provided inside submarine power cables to realize
intertripping and interlocking functions between switchgear feeder and switchgear incomer
located upstream and downstream of the cable.
Optical fibre inside submarine power cables shall comply with IEC standards developed by
technical committee 86 and subcommittees.
For submarine power cables, routine tests, sample tests, type tests and tests after installation
shall be performed as per IEC 63026.
The possibility to keep the validity of type tests performed on similar submarine power cables
shall be as described in clause 12 of IEC 63026:2019.
Reports of all tests on submarine power cables, including type tests on similar cables, shall be
provided.
DC voltage tests of the insulation shall not be permitted for submarine power cables.
Submarine power cables and their accessories, if used for dynamic applications such as
connection to floating installations, shall have been subject to a qualification process.
Submarine power cables and their accessories, if used beyond the water depth limits indicated
in IEC 63026, shall have been subject to a qualification process.
The procedure for the qualification process for submarine power cables shall consider the
conditions of installation.
The procedure for the qualification process for submarine power cables shall consider the
conditions during operational life.
The procedure for the qualification process for submarine power cables shall consider the loads
to which the cable will be subject.
The procedure for the qualification process for submarine power cables shall include a fatigue
analysis.
The qualification process for submarine power cables shall include fatigue testing.
The qualification process for submarine power cables shall be based on technical and scientific
publications.
NOTE: examples of technical and scientific publications on the qualification of submarine power
cables are:
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Cigré TB623 “Recommendations for Mechanical Testing of Submarine Cables”
DNVGL-RP-F401 “Electrical power cables in subsea applications”
The report of the qualification process of submarine power cables shall be provided.
2.9
BULK MATERIALS
2.9.1
Lighting system
2.9.1.1 General
Lighting systems shall comply with EN 12464-1, EN 12464-2, EN 1838.
Luminaires shall comply with 28914.ENG.ELE.STD.
Indoors, LED luminaires shall be used.
Outdoors, LED luminaires shall be used if compatible with ambient conditions.
Incandescent and mercury lamps shall not be used.
LED lighting luminaires shall be selected within risk groups RG0 and RG1, according to IEC TR
62778:2014, Table 1.
Body of luminaires in external areas and in mechanically ventilated spaces drawing outside air
shall be constructed in AISI 316L stainless steel, GRP or aluminium alloy.
The lighting system shall be divided in normal lighting, emergency lighting and emergency
escape lighting.
Normal lighting shall include the whole lighting system of the plant, with exception of
luminaires that switch on only in case of unavailability of main and emergency power sources.
Emergency lighting shall remain operational when the system is powered by the emergency
diesel generators.
Emergency lighting shall be considered an emergency load.
Emergency lighting shall include emergency escape lighting, with exception of luminaires that
switch on only in case of unavailability of main and emergency power sources.
Emergency escape lighting shall remain operational when both main and emergency power
sources are unavailable.
Emergency lighting shall achieve at least 30% of the illumination level required for normal
lighting system.
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The illumination level required for emergency lighting system shall be achieved without the use
of floodlight towers, with exception of roads, yards and storage tank areas.
NOTE: it is permitted to include floodlight towers in the emergency lighting system.
Outdoor lighting system for onshore plants shall be designed maximising the use of floodlight
towers.
Floodlight towers shall comply with 28917.ENG.ELE.STD.
To reduce lighting pollution, floodlight towers shall be fitted with narrow-beam floodlights.
To reduce lighting pollution, if the facility is provided with fence, floodlight towers shall be
provided with screens to prevent the beam of the headlights to come out from the fence.
Local lighting systems (e.g. lighting fixture poles) shall be used in addition to the floodlight
towers system, to illuminate dark areas, stairs, local controls and instrumentations apparatus.
2.9.1.2 Emergency escape lighting
Instantaneous insertion lamps shall be used for emergency escape lighting.
Indoor emergency escape lighting without integral battery shall always be on, with exception
of sleeping rooms (including sleeping rooms in infirmary area) and cinemas.
In sleeping rooms (including sleeping rooms in infirmary area) and cinemas, emergency
escape lighting shall be normally off.
In sleeping rooms (including sleeping rooms in infirmary area) and cinemas, emergency
escape lighting shall be automatically turned on when power is not available on all the AC
incomers to the UPS feeding them.
Emergency escape lighting shall include spot lighting in proximity of communication points
(e.g. phone and interphone locations).
Floodlights shall not be used to concur to the lighting levels required for emergency escape
lighting.
2.9.1.3 Luminaires with incorporated battery
The use of luminaires with incorporated battery shall be limited to indoor areas and plants in
which UPS is not foreseen.
Emergency escape lighting with incorporated battery shall be equipped with control system
that automatically switches on the lamp through battery in case of failure of AC power supply.
Luminaires with incorporated battery shall be fluorescent or LED type.
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Luminaires with incorporated battery shall comply with the requirements for self-contained
emergency luminaires indicated in IEC 60598-2-22.
Autonomy of luminaires with incorporated battery shall be the same as for lighting powered
from UPS, as per opi hse 023 eni spa “Safety & Environmental Minimum Design
Requirements”.
2.9.1.4 Power distribution to lighting system
The lighting system, with exception of emergency escape lighting fed from UPS, shall be fed
from ASP, LP or lighting section of PMCC.
The maximum prospective short circuit current calculated at the busbars of the ASP, LP or
lighting section of the PMCC feeding the lighting system shall be lower than 20 kA.
Outdoor lighting system shall be provided with automatic and manual mode, selectable by
means of a manual selector.
In automatic mode, outdoor lighting system shall be controlled by photocell.
In manual mode, outdoor lighting shall be always on.
For emergency escape lighting fed from UPS, the selector for manual and automatic mode
shall be in the UPS or in the UPS distribution board.
The photocell shall be one for the entire facility.
The power supply for photocell shall be fed by UPS.
Control circuit for photocell shall switch the lights on if a fault occurs in the photocell.
If a fault occurs in the photocell, an alarm shall be raised to the EMS.
It shall not be possible to dim emergency escape lighting.
In UPS distribution boards, feeders to emergence escape lighting shall be separate from
feeders to other users.
2.9.1.5 Additional requirements for lighting inside the buildings
Lighting systems in buildings and cabins, such as electric substations and control rooms, shall
be managed through local lighting distribution panels.
Onshore local lighting distribution panels for buildings shall have different sections for normal
lighting that is not under emergency distribution, emergency lighting and emergency escape
lighting fed from UPS.
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With exception of onshore local distribution panels for buildings, different distribution panels
shall be foreseen for normal lighting that is not under emergency distribution, emergency
lighting and emergency escape lighting fed form UPS.
Each section of local lighting distribution panel for buildings shall be provided with general
circuit breaker.
Each lighting circuit shall be provided with MCB.
In neutral earthing systems different than IT, each lighting circuit shall be provided with RCD.
Indoor lighting shall not be affected by the photocell.
2.9.1.6 Illumination level
Lighting system study shall be performed according to 20231.ENG.ELE.PRG.
The minimum illumination level required for normal lighting shall be in accordance with EN
12464-1, EN 12464-2.
For lighting of battery room, transformer room, power generation room, reference shall be
made to Table 11, point 11.1 of EN 12464-1:2021.
For lighting of control room, reference shall be made to Table 11, point 11.2 of EN 124641:2021.
For lighting of outdoor process areas, reference shall be made to Table 5.10 of EN 124642:2014, with a minimum average illuminance of 100 lux.
The minimum illumination level required for emergency escape lighting shall be in accordance
with EN 1838.
For the purpose of providing escape route lighting according to EN 1838, escape routes shall
be as a minimum those indicated in document “Escape routes, safety signs and safety
equipment layouts”.
2.9.1.7 Additional requirements for lighting in offshore facilities
Lighting for offshore facilities shall comply with EN 12464-1, EN 12464-2, EN 1838 and IEC
61892-2.
Annex G of IEC 61892-2:2019 shall be considered as mandatory for offshore lighting.
For lighting in offshore facilities, in case of conflict between EN 12464 and IEC 61892-2, IEC
61892-2 shall prevail.
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For lighting in offshore facilities, in case of conflict between EN 1838 and IEC 61892-2, IEC
61892-2 shall prevail.
For lighting parameters not specified in IEC 61892-2, the values specified in EN 12464-1, EN
12464-2, EN 1838 shall be used.
Offshore emergency escape lighting shall always be certified EPL “Gb”.
Local distribution panels, local accessories and junction boxes for offshore emergency escape
lighting shall always be certified EPL “Gb”.
2.9.2
Motor Control Station
Motor control stations shall comply with 28915.ENG.ELE.STD.
NOTE: local control of firefighting pumps is not covered in the present document.
NOTE: the requirement for motor control stations is specified in project documents, based on
operability and maintenance considerations.
Motor control stations for LV motors shall be provided with a green LED lamp for motor control
station enabled and with a white LED light for user ready to start.
Motor control stations for LV motors shall be provided with Start-Stop control mode selector
switch.
NOTE: additional ammeter and emergency stop push button are possible if selected in project
documents, according to 28915.ENG.ELE.STD.
Start-Stop control mode selector switch for motor control stations for LV motors shall be
provided with Central (position of rest), Start and Stop positions.
Start position of Start-Stop control mode selector switch for motor control stations for LV
motors shall be closing to the left, with normally open contact and with spring return to central
position.
Stop position of Start-Stop control mode selector switch for motor control stations for LV
motors shall be opening to the right, with normally closed contact, with latched position and
padlockable.
In motor control stations for LV motors, starting shall be operational only if enabled from DCS
or UCP.
In motor control stations, stopping shall be always available.
Local stop in motor control stations for MV motors shall be latched and padlockable in the stop
position.
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If the push button of the motor control station for MV motor is in the stop position, the motor
shall not be seen as available for starting in the DCS or UCP.
NOTE: in motor control stations for MV motors, it is possible to have a stop pushbutton of red
mushroom type, if so selected in project documents, as described in 28915.ENG.ELE.STD.
2.9.3
Power and convenience sockets
Socket outlets and plugs shall comply with COMPANY standard 28915.ENG.ELE.STD.
Convenience sockets shall comply with local rules of the Country where the equipment is
installed.
2.9.4
Conduits
Conduits shall be hot dip galvanized for applications different than road crossing.
Conduits for road crossing shall be heavy PVC or hot dip galvanized.
Each conduit shall be filled with cables for 40% of its capacity or less.
For new facilities, 50% reserve conduit shall be considered in road crossing, considering
maximum filling at 40%.
Pipe conduit penetration through walls, ship decks, hull decks shall not be permitted.
2.9.5
Cable ladders and cable trays
Cable ladders and cable trays shall comply with 28916.ENG.ELE.STD.
Cable trays for power cables shall be of the ladder type.
Cable trays and cable ladders located outdoors shall be provided with cover.
Cable ladders and cable trays for indoor installation shall be made of galvanized steel, AISI
316L stainless steel or GRP.
Cable ladders and cable trays for offshore outdoor installation shall be made of AISI 316L
stainless steel or GRP.
Cable ladders and cable trays for onshore outdoor installation in aggressive environment, such
as coastal area, shall be made of AISI 316L stainless steel or GRP.
Cable ladders and cable trays for onshore outdoor installation in non-aggressive environment
shall be made of galvanized steel, AISI 316L stainless steel or GRP.
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GRP cable trays shall not be used for cables that are required to be fire resistant.
Onshore electrical cable ladders shall be filled with one layer of cables only, with exception of
lighting, small power and electrical control circuits, for which bunched installation is
acceptable.
Offshore electrical cable ladders shall be filled with one layer only of MV cables.
Offshore electrical cable ladders shall be filled with a maximum of two layers of LV cables, with
exception of lighting, small power and electrical control circuits, for which bunched installation
is acceptable.
Cable trays and cable ladders shall have at least 30 cm between the top of the edge of the
cable ladder or cable tray and the bottom of the cable ladder or cable tray above.
Cable trays and cable ladders shall have at least 30 cm between the top of the edge of the
cable ladder or cable tray and the ceiling.
In the space below the false floor of the electrical room, a minimum free space of 80 cm shall
be kept between parallel cable tray routes, to allow the access of a person.
New cable routes shall be designed to keep at least 20% of spare space after project
completion.
All components of cable ladders and cable trays shall be part of VENDOR part list.
The use of parts of cable ladders or cable trays built during construction in yard (like curves, T
sections, slopes) shall be forbidden.
Surface treatments of cable ladders and cable trays for offshore and coastal areas shall comply
with COMPANY Standard 29000.ENG.CPI.STD.
Surface treatments of onshore cable ladders and cable trays shall comply with COMPANY
Standard 29001.ENG.CPI.STD.
Requested durability of surface treatments for cable ladders and cable trays, where mentioned
in 29000.ENG.CPI.STD or 29001.ENG.CPI.STD, shall always be more than 15 years.
Routing of cable ladders and cable trays shall comply with COMPANY Standard
28045.ENG.STA.PRG.
NOTE: in 28045.ENG.STA.PRG, refer to paragraph of instrumentation cable ladders/trays.
Cables connecting adjustable speed electrical power drive systems and thyristor controlled
panels shall be separate from other cables by the maximum distance among what indicated in
28045.ENG.STA.STD, the recommendations of the VENDOR and 10 cm.
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Cable glands
Cable glands shall comply with COMPANY Standard 28915.ENG.ELE.STD.
Effective earth continuity shall be guaranteed between the cable armour or braid and the gland
plate or the internal earth terminal.
2.9.7
Multi-cable Transit (MCT)
MCTs shall be rated for the external factors related to the installation location, considering
corrosion, fire, blast, hazardous location (gas or vapour tightness), water.
Cables shall approach the MCT perpendicularly to the surface in which the MCT is located.
In MCTs, different windows shall be used to segregate power cables from control cables.
MCTs shall be block type.
Unused MCT entries shall be sealed.
Cable transits with foam filling shall be prohibited.
New MCTs shall be sized for 20% spare capacity at project completion.
2.9.8
Electrical resistance trace heating
2.9.8.1 General
Electrical resistance trace heating for hazardous areas and for offshore outdoor locations shall
comply with IEC 60079-30-1, IEC 60079-30-2.
Electrical resistance trace heating for onshore non-hazardous areas and for offshore nonhazardous indoor locations shall comply with IEC 60079-30-1 and IEC 60079-30-2, or with IEC
62395-1 and IEC 62395-2.
Switchgear part of electrical resistance trace heating system shall comply with the
requirements for switchgear stated in the present document and referenced standards.
Local panels part of electrical resistance trace heating system shall comply with the
requirements for Local Distribution Panels stated in the present document and referenced
standards.
Junction boxes part of electrical resistance trace heating system shall comply with COMPANY
Standard 28915.ENG.ELE.STD.
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Power transformers part of electrical resistance trace heating system shall comply with the
requirements for power transformers stated in the present document and referenced
standards.
Power transformers dedicated to electrical resistance trace heating shall have a kVA rating at
least equal to the 125% of calculated maximum electrical resistance trace heating loads.
The choice of protective devices for electrical resistance trace heating system shall consider
the start-up currents and the time necessary to reach the design operating conditions, starting
from the minimum possible temperature.
No more than five heating devices or segments of electrical resistance trace heating system
shall be connected to the same protective device.
At least 20% of back-up trace heaters shall be provided for electrical resistance trace heating
system.
In case of interruption of a single circuit for protection intervention or maintenance, it shall be
possible to switch on a back-up trace heater to keep the required performances of the
electrical resistance trace heating system.
If the electrical resistance trace heating system is classified as emergency service, in case of
fault of a circuit, a back-up trace heater shall be designed to switch on in automatic.
Alarms generated by the electrical resistance trace heating system shall be visible in a manned
location.
As a minimum, alarms shall be raised in case of fault on an electrical resistance trace heating
circuit and in case of temperatures outside the required operating limits.
The fault or unavailability of a single transformer shall not leave any electrical resistance trace
heating service as unavailable.
The fault or unavailability of a single switchgear busbar, or of a single local panel, shall not
leave any electrical resistance trace heating service classified as emergency as unavailable.
The fault or unavailability of a single switchgear busbar, or of a single local panel, shall not
leave any electrical resistance trace heating service necessary for power generation start-up as
unavailable.
The fault or unavailability of a single switchgear busbar, or of a single local panel, shall not
leave any electrical resistance trace heating service necessary for production as unavailable.
Test reports of routine tests on electrical resistance trace heating systems shall be provided.
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2.9.8.2 Electrical resistance trace heating following IEC/IEEE 60079-30-1 and
IEC/IEEE 60079-30-2
For electrical resistance trace heating following IEC/IEEE 60079-30-1 and IEC/IEEE 60079-302, methods to guarantee that sheath temperatures do not exceed the limits required in
IEC/IEEE 60079-30-1 and IEC/IEEE 60079-30-2, with respect to temperature class or ignition
temperature, shall be implemented according to IEC/IEEE 60079-30-1 and IEC/IEEE 6007930-2.
For electrical resistance trace heating following IEC/IEEE 60079-30-1 and IEC/IEEE 60079-302, methods for temperature control shall be implemented according to IEC/IEEE 60079-30-1
and IEC/IEEE 60079-30-2.
Routine tests shall be as per IEC/IEEE 60079-30-1.
For electrical resistance trace heating following IEC/IEEE 60079-30-1 and IEC/IEEE 60079-302, routine tests shall be as per IEC/IEEE 60079-30-1.
For electrical resistance trace heating following IEC/IEEE 60079-30-1 and IEC/IEEE 60079-302, the data indicated in IEC/IEEE 60079-30-2, Annex A, shall be provided in project
specification or data sheet.
For electrical heat tracing systems located in hazardous area, the requirements shall be those
of EPL “Gb” as a minimum.
For electrical heat tracing systems located in non-hazardous areas, but nonetheless required to
follow the requirements of IEC/IEEE 60079-30-1 and IEC/IEEE 60079-30-2, the requirements
shall be those of EPL “Gc” as a minimum.
For electrical resistance trace heating following IEC/IEEE 60079-30-1 and IEC/IEEE 60079-302, documentation requirements shall be as per IEC/IEEE 60079-30-1:2015, clause 7 and
subclauses, and IEC 60079-30-2:2015, 8.7.2.3.
Electrical resistance trace heating following IEC/IEEE 60079-30-1 and IEC/IEEE 60079-30-2
shall comply also with IEC 60079-14.
2.9.8.3 Electrical resistance trace heating following IEC 62395-1 and IEC 62395-2
For electrical resistance trace heating following IEC 62395-1 and IEC 62395-2, methods for
temperature control shall be implemented according to IEC 62395-1 and IEC 62395-2.
For electrical resistance trace heating following IEC 62395-1 and IEC 62395-2, routine tests
shall be as per IEC 62395-1.
For electrical resistance trace heating following IEC 62395-1 and IEC 62395-2, documentation
requirements shall be as per IEC 60519-10:2013, clause 13, and IEC 62395-2:2013, 4.7.11.3.
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Electrical resistance trace heating following IEC 62395-1 and IEC 62395-2 shall comply also
with IEC 60519-10.
2.9.9
Junction boxes
Junction boxes shall comply with 28915.ENG.ELE.STD.
2.10 INSTALLATION REQUIREMENTS
2.10.1 Electrical room building
2.10.1.1
General
Electrical switchgear, with the only possible exception of Local Distribution Panels, shall be
installed in an electrical room.
UPS shall be installed in an electrical room.
Electrical room buildings shall be in non-hazardous area.
Offshore electrical room buildings shall be pressurized according to COMPANY Standard
20452.ENG.MEC.PRG.
Onshore electrical room buildings shall be pressurized according to COMPANY Standard
20453.ENG.MEC.PRG.
Onshore electrical room buildings shall be designed with modular bays guaranteeing their
extension at least at one end of the short side.
In electrical room building, one or more rooms shall be dedicated to spare parts warehouse,
documentation archive and operator workstation.
In electrical room building, the room with operator workstation shall be provided with desk and
seat.
In electrical rooms, free space for escape routes and emergency exits shall be provided.
In electrical rooms, free space for access for operation and maintenance shall be provided.
In electrical rooms, space for cable entries shall be provided.
In new electrical rooms, free space for the addition of at least one column at both ends of each
MV switchgear shall be provided.
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In new electrical rooms, free space for the addition of at least one column at both ends of each
LV switchgear of PC and PMCC type shall be provided.
In electrical rooms, free space for already foreseen future installations shall be provided.
Equipment in electrical rooms shall be installed according to VENDOR instructions.
Equipment in electrical rooms shall be installed according to VENDOR base frame drawings.
In electrical room building, minimum clearances indicated in electrical equipment VENDOR
instructions shall be complied with.
Battery racks shall have a minimum clearance of 800 mm on the front side.
MV switchgear shall have a minimum clearance of 1400 mm on the front side.
If rear accessibility for maintenance is required for MV switchgear, rear side minimum
clearance shall be 800 mm.
LV switchgear shall have a minimum clearance of 1000 mm on the front side.
If rear accessibility for maintenance is required for LV switchgear, rear side minimum clearance
shall be 600 mm.
LV soft-starters shall have a minimum clearance on the front side of 1000 mm.
LV BDM shall have a minimum clearance on the front side of 1000 mm.
UPS shall have a minimum clearance on the front side of 1000 mm.
For electrical equipment with doors, the minimum front side clearance shall be equal to the
door width plus 200 mm.
With circuit-breaker withdrawn and rotated by 90°, the clearance in front of MV switchgear in
withdrawable execution shall not be less than 600 mm.
The clearance in front of LV switchgear with withdrawable parts shall not be less than 600 mm
with equipment withdrawn.
Clearances for power transformers and reactors shall not be less than 800 mm on each side.
Clearances for neutral earthing resistors shall not be less than 500 mm on each side.
The minimum vertical clearance from electrical equipment to ceiling shall be 450 mm, unless a
conduit for the evacuation of gases produced by internal arc is present.
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If a conduit for the evacuation of gases produced by internal arc is present on top of electrical
equipment, the minimum clearances between equipment and ceiling shall be as per VENDOR
recommendations.
If there are flaps on top of electrical equipment for the evacuation of gases produced by
internal arc, the minimum clearances between electrical equipment and ceiling shall be as per
VENDOR recommendations.
In electrical room, at least one access door shall be sized for the passage of the single largest
part of an equipment.
In electrical room, at least one access door shall be sized for the passage of the single largest
switchgear column.
In electrical room, at least one access door shall be sized for the passage of the single tallest
switchgear column.
A free area under the floor of the electrical room shall be provided to allow the installation of
cable trays and cables.
The cable cellar under the electrical room shall have a minimum height of 1800 mm, excluding
the space taken by the structure.
The space under the floating floor of the electrical room shall have a minimum height of 800
mm, excluding the space taken by the structure.
2.10.1.2
Generator room
Generator room shall be in non-hazardous area.
Generator room shall be near the associated step-up transformers, if any.
Generator room shall be near to the electrical room containing the switchgear to which the
generator is connected.
If the generator is in a generator room, the start-up batteries shall be in the generator room.
Cranes necessary for maintenance purpose shall be foreseen in the generator room.
Electrical switchboards and electrical panels shall be permitted in generator room only if
dedicated to the generator (e.g. generator control panel) or to the services of the room (e.g.
local lighting panel), with exceptions of specific requirements of the Classification Society for
offshore facilities.
NOTE: rules of some Classification Societies require that the emergency switchgear is located
in the same room as the emergency generator.
ENGINEERING COMPANY STANDARD
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2.10.1.3
20208.ENG.ELE.PRG
Rev. 14 – June 2022
Page 126 of 135
Transformer bay
Outdoors, power transformers shall be installed in a fenced area or in a room with one side
open to the outside by means of grating or louvers.
A key interlock shall be implemented to guarantee that access to the area in which a
transformer is located shall be possible only if the transformer is de-energized, unless the
transformer is mechanically protected to avoid direct contacts, or if all potentially live parts are
located out of reach, at a minimum height as per indications of IEC 61936-1.
A key interlock shall be implemented to guarantee that access to the area in which a liquid
immersed reactor is located shall be possible only if the reactor is de-energized, unless the
reactor is mechanically protected to avoid direct contacts, or if all potentially live parts are
located out of reach, at a minimum height as per indications of IEC 61936-1.
Only one transformer or reactor shall be located in the same room or fenced area, with
exception of dry type transformers with enclosure rated IP2X as a minimum.
Outdoor transformers shall be covered with canopy, with exception of liquid immersed
transformers connected to overhead transmission lines.
Canopies for power transformers shall be sloped to avoid the stagnation of water.
Neutral earthing resistors connected to transformers shall be placed in proximity of the
transformer to which they are connected.
Liquid immersed transformers and liquid immersed reactors shall be provided with fire
resistant walls, according to IEC 61936-1, if the clearances indicated in IEC 61936-1 are not
achieved.
Liquid immersed transformers and liquid immersed reactors shall be provided with oil
catchment pits.
If liquid immersed transformers are installed in offshore, the requirements of IEC 61936-1
shall be complied with in this respect, in addition to the requirements of IEC 61892-6.
If liquid immersed reactors are installed in offshore, the requirements of IEC 61936-1 shall be
complied with in this respect.
2.10.1.4
Battery room
The electrical equipment inside the battery room shall be certified EPL “Gb”, gas group IIC or
IIB+H2, temperature class T3.
Battery room ventilation shall comply with IEC 62485-2.
Onshore battery room ventilation shall comply with COMPANY Standard 20453.ENG.MEC.PRG.
ENGINEERING COMPANY STANDARD
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20208.ENG.ELE.PRG
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Offshore battery room ventilation shall comply with COMPANY Standard 20452.ENG.MEC.PRG.
A minimum of two extracting fans in 2x100% configuration shall be provided in battery room.
The floor of the battery room shall be resistant to the electrolyte used for the batteries.
Switchgear and UPS shall not be in battery room.
2.10.2 Cabling and wiring
If cables of different insulation voltage levels are installed in the same cable tray, a metal
barrier shall be used to separate them.
If power cables and electrical control/command cables are installed in the same cable tray, a
metal barrier shall be used to separate them.
Instrumentation/automation cables shall not be run in the same cable tray as electrical power
and electrical control/command cables.
NOTE: segregation of instrumentation/automation cable routes is defined in COMPANY
Standard 28045.ENG.STA.PRG.
If cable routes of safety users and firefighting equipment are in cable ladder or cable tray, such
cable ladders and cable trays shall be different from the cable ladders and cable trays of other
users.
Single core cables shall be laid in trefoil or in linear laying with transposition of each phase.
Crossings, passages and penetrations of single core cables shall be realized in non-magnetic
material.
Laying of cables on the floor, on the ground outside of cable trenches, or on the bottom of the
area under false floor, shall not be permitted.
The minimum depth of directly buried underground MV cables shall be 1 m.
The minimum depth of directly buried underground LV cables shall be 0,8 m.
Underground duct banks shall be provided with cable pulling pit at both ends of the duct bank,
to ease cable pulling.
Identification of cables shall comply with COMPANY standard 20198.VAR.LCI.STD.
Identification of cables shall be with AISI 316L labels.
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20208.ENG.ELE.PRG
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Identification labels of cables shall be installed at both cable ends, where the cable changes
the direction, before cable penetrations through structures, after cable penetrations though
structures.
Offshore wall or floor crossing of cables shall be with MCTs.
Onshore wall or floor crossing of cables shall be with MCT, with sleeves welded to the plate or
with sealed threaded transit.
Sleeves welded to the plate shall be sealed with a locking compound and plugging fibre after
the insertion of cables or shall have cable glands screwed to the external side.
Sealed threaded transits shall be provided with threaded locking rings for the closing plate.
2.10.3 Lighting system
Floodlight towers shall be provided with local distribution panel according to COMPANY
Standard 28917.ENG.ELE.STD.
The power on three-phase and three-phase with neutral lighting circuits shall be uniformly
distributed among the three phases.
The power on the single phase distribution to luminaires shall be balanced on the upstream
three phase with neutral supply system.
The power on the phase to phase distribution to luminaires shall be balanced on the upstream
three phase supply system.
The power to adjacent lighting fixtures shall be supplied from at least two different circuits so
that in case of fault or planned cut-off of a circuit, part of the lighting can still be kept in
operation.
To avoid stroboscopic effects, feeding of luminaires in the same areas shall be provided from
different phases.
Circuit breakers feeding lighting circuits shall be designed considering the inrush current of the
luminaires.
In systems other than IT, lighting distribution to luminaires shall be single phase with
exception of floodlight towers and street lights.
In IT systems, lighting distribution to luminaires shall be phase to phase with exception of
floodlight towers and street lights.
If the cable sections cannot be coordinated with the corresponding entrances on the lamp
enclosure, one local junction box for each lighting fixture shall be provided.
ENGINEERING COMPANY STANDARD
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2.10.4 Earthing system
2.10.4.1
HV substations
The earth electrode underneath an onshore HV substation shall have the form of a grid with a
mesh not larger than 5m x 5m.
NOTE: HV substations are excluded from the scope of the present document. Paragraph on
earthing is included because earthing system is usually common with lower voltage levels.
The earth electrode underneath an onshore HV substation shall be sized to comply with IEC
61936-1.
Surge arresters shall be connected with the shortest route and with large elbow bending to the
earth electrode.
In high voltage substations, each equipment shall be connected to the earth electrode by
means of two earthing conductors.
In high voltage substations, each metal structure shall be connected to the earth electrode by
means of two earthing conductors.
Air insulated high voltage substation shall be protected against lightning by means of overhead
earthing wires.
The use as down-conductors of the frame structures supporting the overhead earthing wires of
high voltage substations shall be permitted if their metallic continuity is proven.
2.10.4.2
MV and LV substations
A buried bare-wire ring shall be provided around MV and LV onshore substations.
The buried ring around an onshore substation shall be connected to the general earth electrode
of the plant in at least four points.
Onshore and offshore, a ring of bare conductor shall be provided along the perimeter of the
electrical room or of the relevant cable room.
The ring of bare conductor along the internal perimeter of the electrical room or cable room
shall be connected to the buried ring of the onshore substation in at least four points.
Offshore, the ring of bare conductor along the internal perimeter of the electrical room or cable
room shall be connected to the earth electrode in at least four points.
Each switchgear and UPS, with exception of equipment with double or reinforced insulation,
shall be connected in at least two points to the ring of bare conductor around electrical room or
cable room.
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20208.ENG.ELE.PRG
Rev. 14 – June 2022
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The substation metal structures and concrete reinforcement bars shall be electrically bonded
and connected to the earth electrode.
In substations with concrete flooring, with a pre-welded metal grid, the grid shall be connected
to the earth electrode by means of earthing bars.
2.10.4.3
Electrical equipment
Electrical equipment shall be protected against indirect contacts.
MV equipment different than MV switchgear shall be connected to the earth electrode by
means of at least two different earthing bolts or earthing bars.
LV equipment, with exception of LV switchgear installed in electrical room and of equipment
with double or reinforced insulation, shall be connected to the earth electrode by means of at
least one earthing bolt or earthing bar.
With exception of equipment with double or reinforced insulation, switchgear and control
panels in field shall be provided with an earthing bar to which all PE conductors shall be
connected.
With exception of equipment with double or reinforced insulation, luminaires shall be
connected to the earthing bolt or to the earthing bar of the relevant switchgear by means of a
PE conductor.
With exception of equipment with double or reinforced insulation, onshore luminaires and small
power equipment installed outside the area of the plant earth electrode shall be earthed with a
dedicated earth electrode.
The dedicated earth electrode for luminaires and small power equipment installed outside the
area of the plant earth electrode shall consist of an at least 10 m long buried bare wire, or in a
rod.
PE conductor shall be distributed to all LV users, in TN and IT systems, with exception of
equipment having double or reinforced insulation.
Equipment having double or reinforced insulation shall comply with IEC 60364-4-41.
LV switchgear with double or reinforced insulation shall comply with IEC 61439-1.
UPS with double or reinforced insulation shall comply with IEC 62040-1 and IEC 62477-1.
2.10.4.4
Metal structures, equipment and interconnecting
Metal structures, metal equipment, columns, tanks and rails in the area of the earth electrode
shall be connected to the earth electrode through earthing conductors or other metal
structures.
ENGINEERING COMPANY STANDARD
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20208.ENG.ELE.PRG
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Electrical continuity shall be guaranteed in the piping spools to avoid sparking due to static
electricity.
Piping flanges shall guarantee electrical continuity.
If not achieved through the metal to metal contact on the flange and the flange serrating bolts
(e.g. due to painting insulation thickness or nonconductive gaskets), electrical continuity of
flanges shall be achieved through bonding jumpers directly installed on the flange bolts.
If flange insulation gaskets are foreseen to avoid corrosion between different piping materials,
isolating sparking gap connectors shall be used.
Metal structures, cable trays, cable ladders, rails, pipes and pipelines entering or leaving the
plant earth electrode area shall be interrupted by means of insulating joints.
The armour or braid of electrical cables shall be earthed at both ends, with exception of cables
for adjustable speed electrical power drive systems or thyristor controlled panels.
The armour or braid of electrical cables shall be capable to sustain the earth fault current
flowing through it for the time necessary for the intervention of the protections.
For single core cables, the sizing of the cable shall also consider the flowing of current in the
armour during normal operation.
For electrical cables inside a plant, the screen, if present, shall be earthed at one end only,
with exception of cables for adjustable speed electrical power drive systems or thyristor
controlled panels.
If one end of screened electrical cable is on field or in hazardous area, this is the end at which
the screen shall be earthed, with exception of cables for adjustable speed electrical power
drive systems or thyristor controlled panels.
If the screened electrical cable has no ends in field or hazardous area, the screen shall be
earthed on switchgear side, with exception of cables for adjustable speed electrical power drive
systems or thyristor controlled panels.
The earthing of screen and armour or braid of cables connecting adjustable speed electrical
power drive systems and thyristor controlled panels shall comply with VENDOR
recommendations, providing that unearthed extremities in hazardous areas, if any, are treated
like unused cores as per IEC 60079-14.
The earthing of screen and armour or braid of cables connecting adjustable speed electrical
power drive systems shall comply with the recommendations of IEC TS 60034-25.
Earth wires of MV and HV overhead transmission lines connecting two different facilities shall
be earthed at both ends, with the possible exception of a facility with the earth electrode
connected to a cathodic protection system.
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If a MV or HV cable is connecting equipment located in areas with separate earth electrodes,
and if the earth electrodes are not connected to a cathodic protection system, the armour,
braid and screen shall be earthed at both ends.
If the earth electrodes of two facilities cannot be connected to each other due to reasons
related to cathodic protection, armour, braid and screen of the cables connecting them shall be
electrically interrupted and earthed with a local separate earth electrode before the ingress in
the facility earth electrode area.
Cable armour, braid and screen extremities located in hazardous area shall be earthed.
If a cable has one end with unearthed armour, braid or screen, a specific study shall be made
to verify the voltages between armour, braid or screen and earth on the unearthed side.
If a cable has one end with unearthed armour, braid or screen, unearthed armour, braid or
screen extremities shall be covered and isolated against the possibility of accidental contact
during inspection or maintenance activities.
If a cable has an end with unearthed armour, braid or screen, unearthed armour, braid and
screen extremities shall be isolated with an insulation higher than the earth potential rise.
If a cable is connecting two different facilities of which at least one is offshore, the armour,
braid and screen shall be earthed at least at extremities in offshore.
The earthing system of each of the two facilities connected with a cable shall also be verified
against the possibility of earth fault in the other facility.
The earthing system of each of the two facilities connected with an overhead transmission line
shall also be verified against the possibility of earth fault in the other facility.
A TT system fed from the plant in low voltage and located outside of the plant earth electrode
area shall have its own separate earth electrode.
The earth electrode of a TT system fed from the plant in low voltage and located outside of the
plant earth electrode area shall not be connected to the earth electrode of the plant.
NOTE: the origins of this requirement are the limitations stated in IEC 60364-4-44:2018, Table
44.A2, and the limitations of CEI 64-8:2021, 442.3 for facilities in Italy.
The armour, braid or screen of cables connecting a TT system fed from the plant in low voltage
shall be earthed at one end only.
TT systems fed from the plant in low voltage and located outside of the plant earth electrode
area shall be fed through and isolation transformer located in the plant earth electrode area.
TT systems fed from the plant in low voltage and located outside of the plant earth electrode
area shall have the neutral earthed outside of the plant earth electrode area.
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Isolation transformers feeding a TT system shall be sized to withstand for 1 minute a voltage
equal to the sum of the earth potential rise and of the nominal phase to earth voltage,
between primary and secondary windings and between windings and earth.
Pipes penetrating a structure shall be connected to the earth electrode at the point of
penetration.
The metallic continuity of pipes penetrating a structure shall be verified.
If the metallic continuity of piping penetrating a structure is not verified, equipotential
connections shall be provided.
Earthing connections shall be designed considering cathodic protection systems, if present.
2.10.4.5
Buildings
A bare-wire ring shall be provided around onshore buildings.
The bare-wire ring around onshore buildings shall be horizontally buried at a minimum depth
of 0,5 m.
The bare-wire ring around onshore buildings shall be horizontally buried at a distance between
0,5 m and 1 m from the building perimeter.
The bare-wire ring around onshore buildings shall be connected to earth electrode of the plant
in at least four points by means of earthing terminals or earthing bars.
The main metallic structures of onshore buildings shall be connected at regular intervals not
exceeding 20 m to the bare-wire ring buried under the building.
The reinforcing bars of concrete shall be connected to the bare-wire ring buried under the
building.
2.10.4.6
Metal fences
Metal fences inside the earth electrode area shall be connected to the earth electrode at least
in two points.
Metal fences inside the earth electrode area shall be connected to the earth electrode at least
every 20 m.
Metal fences located outside the plant earth electrode area shall not be connected to the plant
earth electrode.
If there are electrical equipment mounted on fences located outside the plant earth electrode
area (e.g. lighting fixtures, electric gates), the fence and the electrical equipment mounted on
it shall be connected to a local earth electrode buried under the fence itself.
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If there are electrical equipment (e.g. lighting fixtures) nearby fences located outside of the
plant earth electrode area, in such a way that they can be touched at the same time as the
fence, the fence and nearby electrical equipment shall be connected to a local earth electrode
buried under the fence itself.
Electrical equipment mounted on fences located outside the plant earth electrode area shall be
fed through an isolation transformer located inside the plant earth electrode area, with TT
system distribution to the loads.
Electrical equipment located nearby fences located outside of the plant earth electrode area, in
such a way that they can be touched at the same time as the fence, shall be fed through an
isolation transformer located inside the plant earth electrode area, with TT system distribution
to the loads.
If electrical equipment on or nearby a fence located outside of the plant earth electrode area
affect only a small part of the fence, the affected part of the fence shall be insulated from the
other parts.
2.10.4.7
Tankers - mobile containers of flammable materials
Onshore, tankers and other mobile containers of flammable materials shall be connected to the
fixed filling or offloading equipment.
NOTE: for offshore tankers, reference shall be made to the requirements of the Classification
Society.
Onshore, tankers and other mobile containers of flammable materials shall be earthed by
means of specific devices, before the flammable materials are transferred.
Equipment used for bonding, filling or offloading of onshore tankers shall be certified for the
hazardous area.
Connections used for filling or offloading of onshore tankers shall be anti-tearing type which
unlocks automatically in case it is forgotten.
Equipment used for filling or offloading of onshore tankers shall be provided with interrupting
facilities (e.g. auxiliary contacts) to allow the starting of the pump or block it.
2.10.4.8
Pipeline valve control rooms
In pipeline valve control rooms which contain motor-driven valves, located outside of the area
of the earth electrode of the plant and in metallic continuity with the pipeline, the motor
controlling the valve shall not be connected to the earth electrode of the plant.
In pipeline valve control rooms which contain motor-driven valves, located outside of the area
of the earth electrode of the plant, in metallic continuity with the pipeline and fed in low
voltage from the plant, the motor controlling the valve shall be fed in TT system.
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2.10.5 Lightning protection system
Lightning protection system shall be installed according to IEC 62305 series.
2.10.6 Aviation warning lighting
Aviation warning lights shall be installed in accordance with Volume 1 Chapter 6 of ICAO Annex
14.
The luminaires of aviation warning lighting shall consist of a double lamp unit with automatic
changeover to the stand-by lamp upon failure of the operating lamp.
2.10.7 Power and convenience sockets
Power sockets shall be provided for operative and maintenance purposes.
Position of power sockets shall be near to the points of possible use.
In process areas, excluding elevated platforms and passageways, at least one socket with four
poles + PE shall be installed every 30 m of range.
In process areas, excluding elevated platforms and passageways, at least one socket with two
poles + PE shall be installed every 15 m of range.
In process areas, in elevated platforms and in proximity of personnel passageways, at least
one socket with four poles + PE shall be installed.
In process areas, in elevated platforms and in proximity of personnel passageways, at least
one socket with two poles + PE shall be installed.
In buildings and prefabricated cabins, power sockets with four poles + PE, power sockets with
two poles + PE and convenience sockets shall be provided in quantities to be defined during
the project.
Wall mounted convenience sockets in buildings or prefabricated cabins shall be installed at an
elevation not lower than 300 mm from the floor, measured from the socket centre line.
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