TECHNICAL COMMENT SHEET
Rev.
BK-TNG WELLHEAD PLATFORM PROJECT
Project
Document No.: 1014-BKTNG-EL-RPT-0001
Rev
0
Document Title: Electrical Design Basis.
B
Prepared by: T.H. Toai
Checked by: P.H.Viet
Authorised by: L.V.Dung
Sign:
Sign:
Sign:
Date: 24/02/2014
Date: 24/02/2014
Date: 24/02/2014
Sheet No.:
C-1014-BKTNG- EL-RPT-0001
CODE : 1
By
Status:
Status *)
Comment No.
Description
Criticality **)
Comment
O/C/CI
TECHNICAL COMMENTS - FEED
CI
T.H.
Toai
VSP Comment:
This Electrical Design Basis, Rev.0 will be approved with minor
comment as below:
For Sections 6.1:
Last paragraph: Please correct that fuel of GTG is gas only, not dual
fuel.
1
Technip Respond:
Noted. Will be corrected in next issue.
*) O = Open; C = Closed; CI = Closed if implemented in document.
**) NC =Non Conformance (Response required); N=Note (Response required); A=Advice (No Response Required).
Code 1:
Code 2:
Code 3:
Documents to which it has no comments, WORKS can proceed;
Documents to which it has minor comments, WORKS may proceed but CONTRACTOR to revise and resubmit accordingly.
Documents rejected. CONTRACTOR shall re-prepare the documents and re-submit for COMPANY approval.
Page 1 of 1
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TABLE OF CONTENTS
1.0
GENERAL
4
1.1
Background
4
1.2
Purpose of document
4
1.3
Definitions and Abbreviations
5
1.4
Reference Documents
7
1.5
Units of measurements
8
1.6
Language
8
2.0
CODES, STANDARDS AND APPILCABLE DOCUMENTS
8
2.1
Applicable IEC standards
8
2.2
Other standards
11
3.0
ENVIRONMENT CONDITIONS
13
4.0
ELECTRICAL EQUIPMENT ENCLOSURE AND HAZARDOUS AREA CLASSIFICATION
13
4.1
Operational safety and reliability
13
4.2
Standardization of Equipment and Materials
13
4.3
Maintainability and Accessibility
13
4.4
Protection against Explosion and Fire Hazard
14
4.5
Certificates, Declarations and Test Reports
14
4.6
Degree of Protection
15
5.0
ELECTRICAL SYSTEM DESIGN
15
5.1
General
15
5.2
System Voltage
15
5.3
Equipment Operating Voltages
16
5.4
Voltage and Frequency Variation
17
6.0
LOAD ASSESSMENT AND ELECTRICITY CONSUMPTION
17
6.1
Main Power Generators
18
6.2
Distribution Transformers
18
6.3
Emergency Power Generator
18
6.4
Other Electrical Equipments
19
6.5
Short Circuit Ratings
19
7.0
ELECTRICAL POWER GENERATION AND DISTRIBUTION SYSTEM DESCRIPTION
19
7.1
Power Generation System Operation
19
7.2
Power Distribution
19
8.0
DESIGN AND SELECTION OF ELECTRICAL EQUIPMENT
20
8.1
Main Power Generators
20
8.2
Emergency Diesel Generator
22
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8.3
Synchronization:
23
8.4
Power Supply Monitoring and Control System (PSMCS)
23
8.5
6.0kV Switchgear
24
8.6
Distribution Transformer
24
8.7
Neutral Grounding Resistor
25
8.8
400V Switchboard/MCC
25
8.9
Integrated Motor Control Centre (IMCS)
27
8.10
Electric Motors
27
8.11
Variable Frequency Drive (VFD)
28
8.12
Uninterruptible Power Supply (UPS)
29
8.13
Bus duct
30
8.14
Electric Power and Control Cables
31
8.15
Sizing of Cables
32
8.16
Cable Installation
33
8.17
Lighting System
33
8.18
Navigational Aids
36
8.19
Socket Outlets
38
8.20
Multi Cable Transits (MCT)
38
8.21
Cable Glands (stainless steel/ nickel plated brass)
39
8.22
Electrical Heat Tracing
39
8.23
Junction Boxes
40
8.24
Cable Ladder/ Tray
40
8.25
Conduits and Accessories
41
9.0
CONTROL, PROTECTION AND MONITORING
41
9.1
Generator Feeders
41
9.2
Switchgear/ MCC Incomer Feeders
42
9.3
Motor Starters
42
9.4
Transformer Feeder
43
9.5
Feeders
43
9.6
Small Power and Lighting
43
10.0
EARTHING
43
10.1
System Earthing
43
10.2
Equipment Earthing
44
10.3
Lightning Protection
44
11.0
EQUIPMENT CLEARANCE
45
12.0
ELECTRICAL ROOM REQUIREMENT (WITH RAISED FLOOR)
45
13.0
ELECTRIC HEATERS FOR PROCESS/UTILITY APPLICATIONS
46
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1.0
GENERAL
1.1
Background
Thien Ung field is located in the middle part of Block 04-3 in the Nam Con Son Basin,
offshore the Socialist Republic of Vietnam, approximately 15 km of Dai Hung field, and
approximately 270 km southeast of Vung Tau. The Block 04-3 covers an area of
approximately 2600 km2. The Thien Ung field is including its 2 structural parts. Thien Ung
structure discovery was made in 2004 with the 04-3-TU-1X well. Two subsequent
appraisal wells (04.3-TU-2X and 04.3-TU-3X), drilled and tested respectively, delineated
the field.
Location of Thien Ung field is shown in Figure 1.1 below.
Figure 1.1: Thien Ung Reservoir Location
1.2
Purpose of document
The intent of this document is to provide an overview and guidelines for electrical power
generation, distribution, and detail design of the electrical systems and services in Thien
Ung Wellhead platform (BK-TNG).
The design shall fulfill the following engineering/design requirements:

Safe operation and maintenance for personnel as well as equipment

Reliable electrical power generation and distribution systems under all working condition
at site

Efficient power distribution and utilisation

Commonality & interchange ability of equipment

Spare capacity for future load

Ease of operation, and minimum maintenance of equipment

Withstand the technical scrutiny of the third party independent verification body
(appointed by COMPANY)
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The scope of electrical work covers all electrical supplies, main and emergency power
generation, distribution, emergency generation, power system protection, earthing, power
and control cabling, AC UPS systems, small power distribution and wiring, equipment,
materials, lighting and small power, local control stations, navigational aids, and any other
electrical items necessary for the completion of the works within the overall scope of the
project.
It shall be supplemented by, and shall be read in conjunction with:

The Local statutory requirements and laws of the Socialist Republic of Vietnam, as
applicable.

International Codes, Standards and Specifications.
Other Codes, Standards and Specifications which are cross referred in the above
documents shall also be considered.
The minimum technical requirements are defined in this document, they are therefore
subject to evolution and improvements but with the approval of COMPANY.
For more detailed information relevant specifications shall be referred.
1.3
Definitions and Abbreviations
1.3.1
Definitions
PROJECT
FEED service for BK-TNG Wellhead Platform
COMPANY
The party which initiates the project and ultimately pays for its design
and construction and owns the facilities. Here the COMPANY is
Vietsovpetro (Referred to as VSP)
The party which carries out all or part of the design, engineering,
procurement, construction and commissioning of the project
CONTRACTOR
VENDOR
1.3.2
The party on which the order or contract for supply of the equipment /
package or services is placed
Abbreviations
ACB
Air Circuit Breaker
AGRU
Acid Gas Removal Unit
BK-TNG
Thien Ung Wellhead Platform
CCU
Central Control Unit
CWB
Copper Wire Braided (tinned)
DCS
Distributed Control System
ELCB
Earth Leakage Circuit Breaker
ESD
Emergency shutdown (system)
FEED
Front - End Engineering Design
FGS
Fire and Gas System
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FCU
Feeder Control Unit
FPR
Feeder Protection Relay
GCP
Generator Control Panel
IP
Ingress Protection
IMCS
Integrated Motor Control System
HPS
High Pressure Sodium
LSZH
Low smoke zero halogen
HV
High Voltage
LV
Low Voltage
LCS
Local Control Station or Remote Control Unit (RCU)
MBI
Metal Halide
MCB
Miniature Circuit Breaker
MCCB
Moulded Case Circuit Breaker
MCT
Multi Cable Transit
MCU
Motor Control Unit
NGR
Neutral Grounding Resistor or Neutral Earthing Resistor (NER)
PAGA
Public Address and General Alarm
PSMCS
Power Supply Monitoring and Control System
PVE
Petrovietnam Engineering Consultancy Joint Stock Corporation
RCCB
Residual Current Circuit Breaker
SDS
Shut Down System
SWB
Steel Wire Braided (galvanized)
TPGM
Technip Geoproduction (M) Sdn Bhd
TPVN
Technip Vietnam Company Limited
UPS
Uninterruptible Power Supply
UCP
Unit Control Panel
VCB
Vacuum Circuit Breaker
VCU
Vacuum Contactor Unit
VFD
Variable Frequency Drive
VSP
Vietsovpetro
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1.4
Reference Documents
1014-BKTNG-EL-EL-0001
Electrical Load List
1014-BKTNG-EL-RPT-0002
Electrical Load Analysis and Main Equipment Sizing
Calculation
1014-BKTNG-EL-SP-0001
Specification for HV Switchgear
1014-BKTNG-EL-SP-0002
Specification for LV Switchboard/ MCC
1014-BKTNG-EL-SP-0004
Specification for Distribution Transformer
1014-BKTNG-EL-SP-0005
Specification for AC UPS
1014-BKTNG-EL-SP-0007
Specification for Navigational Aids System
1014-BKTNG-EL-SP-0008
Specification for LV Motors
1014-BKTNG-EL-SP-0010
Specification for Electrical Cables
1014-BKTNG-EL-DS-0001
Datasheet for HV Switchgear
1014-BKTNG-EL-DS-0002
Datasheet for LV Switchboard/ MCC
1014-BKTNG-EL-DS-0003
Datasheet for Distribution Board
1014-BKTNG-EL-DS-0004
Datasheet Distribution Transformer
1014-BKTNG-EL-DS-0005
Datasheet for AC UPS
1014-BKTNG-EL-DS-0007
Datasheet for Navigational Aids System
1014-BKTNG-EL-DS-0008
Datasheet for LV Motors (Typical)
1014-BKTNG-EL-DS-0010
Datasheet for Gas Turbine Generator (GTG)
1014-BKTNG-EL-DS-0011
Datasheet for Emergency Diesel Generator (EDG)
1014-BKTNG-PR-RPT-0001
Process and Utility Design Basis
1014-BKTNG-ME-SP-0016
Specification for Gas Turbine Generator Package
1014-BKTNG-ME-SP-0017
Specification for Emergency Diesel Generator
Package
1014-BKTNG-ME-DS-0010
Datasheet for Gas Turbine Generator Package
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1.5
Units of measurements
The International System of units (S.I.) shall be used in all drawings and documentation
unless otherwise stated.
1.6
Language
All drawings, documentation and correspondence shall be in the English Language.
2.0
CODES, STANDARDS AND APPILCABLE DOCUMENTS
The electrical system design shall generally comply with the latest revision and relevant
sections of the following regulations, standards and codes of practices.
The applicable laws, international codes and standards are as follows:
Relevant Laws of Socialist Republic of Vietnam
International Electrotechnical Commission (IEC), and other standards listed in section 2.1 of
this document.
Note: Unless specifically designated by date, the latest edition of each publication shall be
used, together with amendments, supplements or revision thereto.
2.1
Applicable IEC standards
IEC 60034 Series
Rotating Electrical Machines
IEC 60038
IEC Standard Voltage
IEC 60044-1
Instruments Transformers – Part 1: Current Transformer
IEC 60044-2
Instruments Transformers – Part 2: Inductive Voltage Transformer
IEC 60050
International Electro technical Vocabulary
IEC 60071
Insulation Co-ordination
IEC 60072 Series
Dimensions and output series for rotating electrical machines
IEC 60073
Basic and Safety Principles for Man-machine Interface, Marking
and Identification - Coding Principles for Indicators and Actuators
IEC 60076
Power transformers (all parts applicable to dry type power
transformers)
IEC 60079
Electrical Apparatus for Explosive Gas Atmospheres.
IEC 60079-30
Electrical Apparatus for Explosive Gas Atmospheres – Electrical
resistance heat tracing.
IEC 60085
Thermal evaluation and classification of electrical insulation
IEC 60092-350
Electrical Installations in Ships - Part 350: Shipboard power cables
- General construction and test requirements
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IEC 60092-351
Electrical Installations in Ships - Part 351: Insulating materials
for shipboard and offshore units, power, control, instrumentation,
telecommunication and data cables
IEC 60092-352
Electrical Installations in Ships - Part 352: Choice and installation
of electrical cables
IEC 60092-353
IEC 60092-354
Electrical Installations in Ships - Part 353: Single and multi-core
non-radial field power cables with extruded solid insulation for
rated voltage 1 kV and 3 kV
Electrical Installations in Ships - Part 354: Single -and three-core
power cables with extruded solid insulation for rated voltages 6
kV (Um = 7,2kV) up to 30 kV (Um = 36 kV)
IEC 60092-359
Electrical Installations in Ships - Part 359: Sheathing Materials for
Shipboard Power and Telecommunication Cables
IEC 60092-376
Electrical Installations in Ships - Part 376: Cables for control and
instrumentation circuits 150/250 V (300 V)
IEC 60099
Surge Arresters
IEC 60137
Bushings for Alternating Voltages Above 1000V
IEC 60146
Semiconductor converters
IEC 60228
Conductors of insulated cables
IEC 60255
Electrical relays (all parts relevant to Project application)
IEC 60269
Low-voltage fuses
IEC 60270
Partial discharge measurements
IEC 60282
High-voltage fuses
IEC 60287
Electric cables – Calculation of the current rating
IEC 60331
Fire resisting characteristics of electric cables
IEC 60332
Tests on electric cables under fire conditions
IEC 60391
Marking of insulated conductors
IEC 60404
Magnetic Materials (all parts relevant to Project application)
IEC 60439
Low voltage switchgear and control gear assemblies
IEC 60445
Basic and safety principles of man-machine interface, marking and
identification
- Identification of equipment terminals and conductor terminals
IEC 60446
Identification of conductors by colors or numerals
IEC 60470
High-voltage A.C. contactors
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IEC 60502:2006
Extruded solid dielectric insulated power cables for rated voltages
from 1kV to 30 kV
IEC 60514
Acceptance Inspection of Class 2 Alternating Current Watthour
Meters
IEC 60529
Classification of Degrees of Protection Provided by Enclosures
IEC 60623
Ni Cd stationary batteries
IEC 60664
Insulation co-ordination for equipment within low-voltage systems
IEC 60688
Electrical measuring transducer for converting A.C. electrical
quantities to analogue or digital signals
IEC 60754
Test on gases evolved during combustion of materials from cables
(Part 1 & Part 2)
IEC 60811
Common test methods for insulating and sheathing materials of
electric cables
IEC 60836
Specification for Silicone Liquids for Electrical Purposes
IEC 60885
Electrical test methods for electric cables
IEC 60896
Stationary lead-acid batteries (Part 21: Valve regulated types
methods of test & Part 22: Valve regulated types requirements)
IEC 60898-1
Circuit-breakers for overcurrent protection for household and
similar installations
IEC 60909
Short-circuit currents in three-phase a.c. systems
IEC 60947
Low voltage switchgear and control gear
IEC 61000
Electromagnetic compatibility (EMC)
IEC 61034
Measurement of smoke density of electric cables burning under
defined conditions
IEC 61140
Protection against electric shock – common aspects for installation
and equipment
IEC 61204
Low voltage power and supply devices, DC output – Performance
characteristic
IEC 61515
Mineral insulated thermocouple cables and thermocouples
IEC 61850 Series
Communication Networks and Systems in Substations
IEC 61892
Mobile and Fixed Offshore Units - Electrical Installations (all parts
relevant to Project application)
IEC 62040
Stabilized Power Supplies, D.C. Output
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IEC 62271
2.2
High-voltage switchgear and control gear (all parts relevant to
Project application)
Other standards
API RP 14FZ
Design and Installation of Electrical Systems for Fixed and Floating
Offshore Petroleum Facilities for Unclassified and Class I, Zone 0,
Zone 1 and Zone 2 Locations
IES
Lighting Handbook
IES RP-12
Recommended Practice for Marine Lighting
CAP 437
Civil Aviation Authority (London) Offshore Helicopter Landing
Areas : A Guide to Criteria, Recommended Minimum Standards
and Best Practices
NFPA 496
Standard for Purged and Pressurized Enclosures for Electrical
Equipment in Hazardous (Classified) Locations
NEMA MG 1
Motors and Generators
NEMA MG 2
Safety standard and guide for selection, installation and use of
electric motors and generators
NEMA VE 1
Metal Cable Tray Systems
NEMA VE 2
Cable Tray Installation Guidelines
IALA
International Association of Lighthouse Authorities
NEK606
Cables for Offshore Installations Halogen Free, or Mud Resistant
NFPA 70
National Electrical Code (2011)
IEE
Recommendations for the electrical and electronic equipment of
Mobile and Fixed offshore Installations
NFPA-780
Standard for the Installation of Lightning Protection Systems
IEEE std 32
Standard Requirements, Terminology, and Test Procedures for
Neutral Grounding Devices
IEEE std 515
IEEE Standard for the Testing, Design, Installation, and
Maintenance of Electrical Resistance Trace Heating for Industrial
Applications
IEEE std 844
IEEE Recommended Practice for Electrical Impedance, Induction,
and Skin Effect Heating of Pipelines and Vessels
IEEE std 519
IEEE Recommended Practices and Requirements for Harmonic
Control in Electrical Power Systems
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IEEE std 484
IEEE Recommended Practice for Installation Design and
Installation of Vented Lead-Acid Batteries for Stationary
Applications
IEEE std 485
IEEE Recommended Practice for Sizing Lead-Acid Batteries for
Stationary Applications
IEEE std 142
IEEE Recommended Practice for Grounding of Industrial and
Commercial Power Systems
IEEE std 242
IEEE Recommended Practice for Protection and Coordination of
Industrial and Commercial Power Systems
ISO 13702
Petroleum and natural gas industries - Control and mitigation of
fires and explosions on offshore production installations
API 500
Recommended Practice for Classification of Locations for
Electrical Installations at Petroleum Facilities Classified as Class I,
Division I and Division 2
API 505
Recommended Practice for Classification of Locations for
Electrical Installations at Petroleum Facilities Classified as Class I,
Division I and Division 2, Third Edition
SOLAS 2004
Safety Of Life At Sea
DNV-OS-A101
Safety principles and Arrangements
DNV-OS-D201
Electrical Installations
DNV-OS-D202
Automation, Safety, and Telecommunication Systems (Oct. 2008)
The design and engineering of the electrical installation shall satisfy all statutory
requirements of the national and/or local authorities.
The electrical installation shall be suitable for the site conditions.
In the event of contradiction between the requirements of this document, IEC, ISO, NFPA,
DNV, NEMA, API, the particular IEC requirement shall prevail, provided the statutory
obligations of both local and national authorities of the Socialist Republic of Vietnam are
satisfied.
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3.0
ENVIRONMENT CONDITIONS
All electrical equipments installed outdoors shall be suitable for operation on offshore
environment conditions. Electrical equipment installed indoors shall normally be operated
in air conditioned environment; however they shall be suitable for short time duty in the
outdoor environmental conditions prevailing at site, without temperature rise of any part of
the electrical equipment exceeding the maximum permissible temperature rise values
stipulated in the relevant IEC standards. The design environmental and climatic data are
summarised below:
Atmosphere
:
Saliferous and Marine
Temperature outdoor
:
Maximum ambient = 390C
Minimum ambient = 210C
Relative humidity
:
Average ambient
= 27.10C
Maximum
= 98 %
Minimum
= 62 %
Indoor Temperature
+ With Air-conditioning
:
240C , +/- 20C (Switchgear/MCC Room)
200C, +/- 20C (Battery Room)
+ Without Air-conditioning
:
+Δ50C compare to outdoor temperature. Design room
max is 440C (ventilation only)
For all the other relevant environmental data, refer to Doc. No.: 1014-BKTNG-PR-RPT-0001;
Document Title: “Process and Utility Design Basis”.
4.0
ELECTRICAL EQUIPMENT ENCLOSURE AND HAZARDOUS AREA CLASSIFICATION
4.1
Operational safety and reliability
The design of the electrical installation shall be based on the provision of a safe and
reliable supply of electricity at all times. Safe conditions shall be ensured under all
operating conditions, including those associated with start-up and shutdown of plant and
equipment, and throughout the intervening shutdown periods. The design of electrical
systems and equipment shall ensure that all operating and maintenance activities can be
performed safely. Provisions for alternative supply sources and supply routes, spare/standby capacity and automatic restarting schemes are required.
4.2
Standardization of Equipment and Materials
Equipment of similar nature, identical components and construction should be of the same
manufacturer. This applies to HV switchgear, LV Switchboard, MCC, transformers, power
and convenience outlets and luminaries, local control station, battery and safety switch.
Standardization of materials and equipment shall be aimed for and compatible with rational
design. Equipment which will become obsolete in the near future shall not be selected.
4.3
Maintainability and Accessibility
Electrical facilities shall be designed, constructed and installed so that components of the
facilities are accessible for maintenance and capable of being repaired and replaced.
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4.4
Protection against Explosion and Fire Hazard
Hazardous area classification drawings and document prepared by the Process Safety
Discipline. This shall be used as the basis for the proper selection of electrical equipment
and installations.
Electrical equipment should, as far as practical and economic, be located in the least
hazardous areas. Electrical equipment installed in hazardous area shall have a type of
protection suitable for the relevant zones and specified in accordance with IEC 60079.
Electrical equipment installed in indoor, non-hazardous areas within process areas shall be
of a standard industrial type as specified in the relevant equipment design requirements.
Although many types of protection are available, the following shall be used in the final
selection:
- For Zone 1, LV motors and all inherently non-sparking equipment, e.g., junction boxes
and luminaires, shall have type of protection ‘d’, ‘de’ or 'e'. HV motors and all inherently
sparking equipment, e.g., switchgear and controlgear, shall have type of protection 'd' or
‘de’. Where such type of protection is not available, e.g., large high speed HV motors, type
of protection 'p' shall be used. HV motors with type of protection 'e' shall not be used in
zone 1 area.
- For Zone 2, motors and inherently non-sparking equipment shall have type of protection
'n', all equipment approved for Zone 1 is also acceptable. Inherently sparking equipment
shall have type of protection 'd', ‘de’ or 'p', as stated for Zone 1.
For a process plant/ unit having Zone 2 hazardous area, outdoor non-hazardous area
within its extent, Zone 2 equipment shall be installed to cater possibility of reclassification,
interchange-ability of equipment and their spares. These criteria shall be applicable to
equipment like motors, lighting fixtures, remote control units and welding and convenience
sockets.
Equipment installed in non-hazardous areas such as within living quarters shall be
standard-industrial type/ domestic type depending upon type of installation and/ or
application.
For the installation of electrical equipment in hazardous areas, IEC 60079-14 shall be
complied with and shall be certified by the approved authorities such as Baseefa in UK,
PTB in Germany, LCIE in France, CSI in Italy, UL and FM in USA, CSA in Canada.
All hazardous area equipment shall be indexed against area classification, certification,
and required maintenance to maintain certification validity. Copies of all hazardous area
certificates or certificate of conformity shall be provided for all electrical/ electronic
hazardous area equipment, in the English language.
4.5
Certificates, Declarations and Test Reports
For all major equipment, shall be obtained at least the Manufacturer’s test reports in
accordance with the equipment design requirements, e.g., for generators, motors, HV and LV
switchgear, UPS equipment and transformers.
Further certificates or declarations relating to the application of equipment for use in
hazardous areas may be required by local authorities, according to the following rules:
a) For electrical apparatus in Zone 0, Zone 1 and Zone 2 areas, a certificate of conformity
shall be obtained from the Manufacturer/Supplier.
b) For electrical apparatus in Zone 2 areas, which has type of protection ‘n’, a declaration of
compliance may be accepted instead of a certificate of conformity.
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4.6
Degree of Protection
Unless otherwise specified in the equipment specification, the following minimum degrees
of protection of the enclosure against contact with live or moving parts and against ingress
of solid foreign bodies and liquid shall be selected, in accordance with IEC 60529:
Indoors (with HVAC system)
HV switchgear
:
IP32
-
LV switchboard / MCC
:
IP41
-
UPS (Indoors with HVAC system)
:
IP31
-
Ex-battery & enclosure
:
IP44
:
IP23
Indoors (without HVAC system)
-
Dry Transformer (in enclosure)
Outdoors areas
-
Switch-rack, outdoor luminaire and JB
:
IP56
-
Electric motors, alternators (outdoors/indoors)
:
IP56
IP of other equipment/devices/materials shall be according to DNV-OS-D201
5.0
ELECTRICAL SYSTEM DESIGN
5.1
General
The design of the electrical installation shall be based on the fundamental principles
referred to above.
The designs and philosophies relating to the electrical system shall be adequately
illustrated by a system design description, a key single line diagram, detailed single line
diagrams, layout drawings, installation details, specifications, calculations and etc as
required.
System studies, protection reports and the like shall be provided in support of the design,
as required by relevant codes, standards and good engineering practice.
Power system studies shall be carried out using suitable and applicable software.
5.2
System Voltage
The electrical system voltages for the BK-TNG shall be as follows:
Generation voltages and frequency:
HV generation
=
6.0kV, 3-phase, 3-wire, 50Hz
LV generation
=
400/230V, 3-phase, 4-wire, 50Hz
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Distribution/Utilization voltages and frequency:
5.3
HV System
=
6.0kV, 3-phase, 3-wire, 50Hz
LV System
=
400/230V, 3-phase, 4-wire, 50Hz
=
230V, 1-phase, 2-wire, 50Hz
Equipment Operating Voltages
The system details at various utilisation equipment voltages shall be as given below:
Service
Voltage
Phase
HV Main Power Generator
6.0kV
50Hz , 3-phase, 3-wire
HV Power Distribution
6.0kV
50Hz , 3-phase, 3-wire
Motor rated above 200kW (Note 1)
6.0kV
50Hz , 3-phase, 3-wire
Motors rated 200kW and below
400V
50Hz , 3-phase, 3-wire
Emergency Power Generator
400V
50Hz , 3-phase, 4-wire
LV Power distribution
400V
50Hz , 3-phase, 4-wire
Lighting & Small Power
230V
50Hz , 1-phase, 2-wire
HV Switchgear :
Motor VCU Control
230V
50Hz , 1-phase, 2-wire
Uninterruptible Power Supply
Voltage
Phase
Navigational Aids
24V
DC UPS
Helideck Lights, Aviation Obstruction
Lights
230V
AC UPS, 50Hz , 1-phase,
2-wire
DCS, ESD, FGS, Public Address and
Alarm (PAGA) System
230V
AC UPS, 50Hz , 1-phase,
2-wire (Redundant)
Turbine/ Emergency/ Gas Engine
Generator Control Panel, Turbine
compressor control panel and critical
mechanical package control panel
230V
AC UPS, 50Hz , 1-phase,
2-wire
Telecommunication
230V
AC UPS, 50Hz , 1-phase,
2-wire
VCB & ACB tripping/closing circuit, and
protective relays and signalization
230V
AC UPS, 50Hz , 1-phase,
2-wire (Refer Note 2)
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Uninterruptible Power Supply
Turbo Machinery (back-up) DC post
lube oil pump
Voltage
Phase
230V
AC UPS, 50Hz , 1-phase,
2-wire
Note 1: Approval for using 400V driver motors rated above 200kW, may be considered on a
case-to-case basis by COMPANY.
Note 2: Any other required operating voltage should be derived internally by Manufacturer.
5.4
Voltage and Frequency Variation
The electrical system shall be designed based on the following criteria:
a) Under steady state condition, the voltages at all points on the system shall be kept
between +5% and –5% of the nominal voltage and the frequency shall be maintained
within +/-2% of rated frequency.
b) The voltage dip during large motor starting as per the following:- 15% for voltage dip at Switchgear/MCC bus
- 20% at motor terminal for HV motors (DOL)
- 20% at motor terminal for LV motors (DOL)
Voltage transient due to load variation tolerance shall be +/-20% from nominal voltage as per
IEC 61892-1.
6.0
LOAD ASSESSMENT AND ELECTRICITY CONSUMPTION
A schedule of the installed electrical loads, the maximum normal running load and the peak
load, expressed in kilo-watt, kilo-VAr and kilo-VA and based on the facility design capacity
when operating under the site conditions specified, shall be prepared.
It shall be completed and updated regularly throughout the design stage of the project and
shall form the basis for provision of the necessary electricity supply and distribution system
capacity.
The following formulas shall be used for determining the total electrical loads:
Maximum Load
=
The larger value of either {A + (0.3xB)} or
{A + Largest Single Intermittent Load}
Peak Load
=
The larger value of either {Maximum load + (0.1xC)} or
{Maximum Load + Largest Single Standby Load}
Where:
A = Total sum of Continuous Loads (in Load List)
B = Total sum of Intermittent Loads (in Load List)
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C = Total sum of Standby Loads (in Load List)
All known future loads for Continuous, intermittent and standby operation shall also be
defined and included in the equipment sizing.
The capacity of the electrical points of supply (generation, and associated switchgear) shall
be capable of supplying continuously 120% of the peak load, assessed according to the
applicable load data, without exceeding specified voltage limits, and equipment ratings.
6.1
Main Power Generators
There shall be two (2) nos. of gas turbine driven main power generators (1 + 1) on BK-TNG.
Each of the main power generators shall be sized to cater for 100% of the total (ultimate) load
of the BK-TNG during normal operation. Hence, one of the two main power generator shall
act as the duty machine, the remaining unit to act as the “cold” standby machine.
The main power generation shall be capable of fulfilling at least the following specific
requirements:
a) Supplying maximum load and simultaneously starting the largest motor load, with the
spare unit inoperative in accordance with the load list summary.
b) Maintaining the stability of the electrical system in response to step changes in load or
available power.
c) Maintain adequate spare capacity for known future loads as shown in electrical load list
and mechanical equipment list.
Main power generator plant site rating should be capable of sustaining at least 120% of the
calculated “peak load”.
The two main power generators installed shall have gas fuel capability of using treated well
gas as fuel.
6.2
Distribution Transformers
Dry type cast resin distribution transformers shall be used. Two distribution transformers
feeding into each main LV switchboard and shall be rated for 2 x 100% configuration – i.e.
Both operating transformers shall be capable of catering to at least 100% of the entire main
LV switchboard load.
Transformers shall be sized to handle the tabulated peak operating load, plus 20% spare
capacity.
6.3
Emergency Power Generator
In the event of loss of mains power supply from all the main power generators, emergency
electrical power to the BK-TNG will be supplied by an emergency power generator. The
emergency power generator shall be sized to cater for all the life support loads, essential
process and utility loads, essential Living Quarters (LQ) loads plus black-starting loads (i.e.
those necessary to allow restarting of the first main power generator).
The emergency power generator shall have battery start (primary) and hydraulic (secondary)
start facilities.
The emergency power generator shall have additional at least 20% spare capacity of the
calculated emergency ‘peak load’ in anticipation for future load growth.
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6.4
Other Electrical Equipments
Unless otherwise specified, other electrical not identified on the above shall be sized based
on the peak load plus 20% spare capacity.
6.5
Short Circuit Ratings
All equipment shall be capable of withstanding the effects of short circuit currents and
consequential voltages arising in the event of equipment or circuit faults.
The short circuit ratings of equipment and cables, including the short circuit making and
breaking capacity of circuit switching devices, shall be based on parallel operations of all
supplies which can be paralleled during normal-operations; it will also include the contribution
that can be expected from the connected load.
The use of current-limiting reactors, Is-limiters and similar devices intended specifically as a
means of limiting the magnitude of short circuit currents shall not be used.
7.0
ELECTRICAL POWER GENERATION AND DISTRIBUTION SYSTEM DESCRIPTION
7.1
Power Generation System Operation
The main generating plant shall consist of 2 x 100% gas turbine driven 6.0kV, 50 Hz, 3-phase
main power generators.
Emergency power shall be provided at 400/230V, 50 Hz, 3-phase, 4wire by an Emergency
Power Generator.
The emergency power generator shall start automatically on detection of mains failure – and if
ESD permitting. It shall be capable of starting, accelerating to operating speed, and carrying
load after actuation of start signal. The emergency power generator shall be capable of
continuous parallel operation with main power turbine generators.
The electrical power distribution system shall initially be energised by emergency power
generator. The system control operator has at this point to select the main duty power
generators (to be started-up) and close low voltage breakers needed to energise the selected
main power generator auxiliaries and utility loads.
From the selected machine control panel location a manual start shall be attempted. Upon a
successful main generator start, generator feeder breaker shall be closed to energise the HV
Switchgear and downstream power distribution system.
During commissioning and in case of emergency power generator also fails, temporary power
supply generator shall feed power to selected LV loads.
Once the 400V switchboards are energized from the main power generator, the emergency
power generator can be taken off-line and run-down.
A trip signal originating from a generator control panel shall trip the generator circuit breaker
and the excitation system and prime mover.
7.2
Power Distribution
The power distribution system philosophy requires electrical systems to be designed to
maximize flexibility, reliability and maintainability. The ultimate goal during distribution system
design is to allow for reliable process operation concurrent with ongoing isolation and
maintenance of selected parts of the electrical system.
The project distribution system voltages shall be as follows:
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a) 6.0 kV, 50Hz, 3-phase, 3-wire, low resistance grounded wye shall be utilised for power
generation and distribution;
b) 400/230V, 50Hz, 3-phase, 4-wire, solidly grounded wye shall be utilised for distribution to
motor control centres;
c) 400V, 50Hz, 3-phase, 3-wire, un-grounded wye shall be utilised for LV distribution (where
necessary).
The design of low voltage (400/230V, 50Hz, 3-phase, 4-wire) power distribution system shall
be provided with both main bus sections and emergency bus sections. An auto-transfer
switch system shall transfer power supply from main generator (normal) supply to emergency
generator supply and vice versa (re-transfer). Both “Transfer” and “re-transfer” shall be
effected by “make-before-break” principle so as to realise a no-break transition - when both
sources are available.
High voltage (6.0kV, 50Hz) switchgear comprising bus section ‘A’ and bus section ‘B’,
normally closed bus-coupler, main generator incomers and outgoing feeders/motor starters.
For 400/230V consumers, the 6.0kV supply is stepped-down to main 400/230V
Switchboard/MCC through 6.0/0.420 kV distribution transformers.
All electric power consumed by the LQ shall be derived from the BK-TNG power distribution
system.
Dual redundant feeders shall be utilised for transmitting 400/230V AC normal & emergency
power, and AC UPS power from BK-TNG to LQ.
8.0
DESIGN AND SELECTION OF ELECTRICAL EQUIPMENT
Design life for all facilities shall be 25 years. Equipment/materials must have at least 2 years
of proven offshore field experience with good client reference. All equipment/material shall be
sourced from the approved Manufacturer list which had been approved by COMPANY.
Main Power Generators shall be installed in a well-ventilated Main Power House and
Emergency Power Generator shall be housed in a movable Emergency Generator Room.
Separate HV Switchgear room, Transformer room, LV MCC room and UPS/ Emergency MCC
room, Battery room shall be provided.
8.1
Main Power Generators
The 6.0kV turbine driven main power generators shall be designed and constructed in
accordance with the Project Specification for Power Generators (1014-BKTNG-ME-SP-0016)
and Project Datasheet Power Generators (1014-BKTNG-ME-DS-0010 & 1014-BKTNG-ELDS-0010).
The main power generator skids shall be housed in a 316L stainless steel clad weather-proof
/ acoustic enclosures, and designed and certified suitable for operating in Zone 2 hazardous
location.
8.1.1
Generator System Control
The generator control system shall cater to “n + 1” configuration of 6.0kV, 3 -phase, 50Hz, 0.8
power factor, low resistance grounded turbine driven main power generators - where n=1.
The main power generators shall each be furnished a package comprising an enclosed skid
mounted turbine driver/generator assembly and a remotely mounted PLC based unit control
panel (GCP) complete with all controls, governors, automatic voltage regulator and ancillary
equipment.
Generator shall be suitable for operation:
a) In stand-alone operation
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b) Parallel with the other main power generators
c) Parallel with the emergency power generator
The turbine generator control panels shall include but not limited to the following:
a) Power generation system
b) Control and metering
c) Generator protection relays
d) Interface with Power Supply Monitoring and Control System (PSMCS)
The GCP for each main power generator shall consist of a turbine control section and an
alternator control section. The complete unit for each machine shall be installed as to form a
single row of control panels (for all machines) in the control room.
All control and operation functions of the main power generators and emergency power
generators shall be located on the individual generator(s) control panel which provides unit
control and protection.
There is no intention of remote operation of any machine, except from the PSMCS [described
in 8.3].
Emergency stopping of the main generator shall be effected either by depressing the
generator control panel mounted “emergency push button” for the respective main generator
GCP or a similar hard wired “emergency stop” push button located adjacent to each main
generator package skid.
Emergency stop trip signal from ESD shall be similarly routed to the GCP.
The main generators shall be provided with automatic control schemes. This shall include the
facilities for auto-starting, automatic synchronising and automatic loading.
Main Generation shall be controlled as follows:

Isochronous and droop speed control.

Isochronous and droop voltage control
Voltage control equipment consisting of automatic voltage control with a manual control
stand-by system. Manual control system shall follow the set point of the automatic control
system to allow for automatic changeover from the automatic to the manual control system
without significant voltage transients in the case of the automatic voltage control system
failure. Reactive-Power sharing among sets shall be provided for the voltage control system.
Each main generator shall be provided with the alarm equipment, indicating instruments and
integrating meters and generator protection relay.
The main generator shall be equipped with a brushless exciter consisting of a three phase
synchronous initiating rectifier assembly and a permanent magnet generator (PMG) pilot
exciter. The excitation system shall comprise at least the following:

External excitation equipment

Duplicate (Main/Standby) Automatic Voltage Regulators (AVR)

Voltage adjuster (rheostat)

AVR excitation failure relay (alarm)
The AVR shall be of the electronic type provided with a fine voltage adjuster. It shall include
frequency sensing circuitry to limit the ceiling voltage and to prevent damage to components
when the generator is driven at reduced speeds, such as when starting or when the engine is
at idling speed.
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The AVR shall be matched to the generator characteristics and should be installed in the
generator control panel.
Generator shall be equipped with a damper winding on the rotor for parallel operation. Both
‘isochronous’, and ‘quadrature droop compensation’ of maximum 5% at full load shall be
provided. A droop current transformer and droop rheostat shall be provided.
Generators shall be equipped with manual and automatic synchronising facilities including a
check synchronising relay and a dead-bus override. In addition automatic synchronising and
continuous load sharing with main power generation shall be provided.
Mimic diagram based on the key single line diagram shall be made available in the PSMCS to
display main circuit breaker status for both the HV Switchgear and the LV Switchboard/MCC.
It shall also include alarm and trip indication for each breaker.
Generator control panel shall have an HMI for displaying live graphics that describe the
workings and condition of the respective generator units.
8.1.2
Generator System Protection, Metering and Monitoring
The primary location for the metering, control, protection and monitoring of each generator
shall be at their respective GCPs.
Secondary metering and monitoring locations shall be the DCS. The DCS shall serve the
function of repeating selected status points, analogue values and all distribution alarms and
trips and displaying at the DCS console in the Central Control Room.
Salient power generation data from GCP to DCS shall be transmitted by redundant RS 485
serial link with MODBUS protocol.
8.2
Emergency Diesel Generator
The 400/230V emergency power generator shall be designed and constructed in accordance
with the Specification for Emergency Diesel Generator Package (1014-BKTNG-ME-SP-0017)
and Datasheet for Emergency Diesel Generator (1014-BKTNG-ME-DS-0011 & 1014-BKTNGEL-DS-0011).
A diesel engine driven Emergency Power Generator shall be provided, rated 400/230V, 50Hz,
3-phase, 4-wire, 0.8 power factor, neutral solidly grounded. The emergency power generator
package shall be furnished as a skid mounted package (consisting of prime mover, cooling
system, dual starting systems, exhaust system, ventilation system and alternator) housed in a
316L stainless steel clad weather-proof / acoustic enclosure - designed and certified suitable
for operating in Zone 2 hazardous location. The balance of equipment shall be housed in a
GCP consisting of the controls, speed governor, automatic voltage regulator shall be installed
remotely in the Emergency Electrical switchgear/MCC room.
Facilities for automatic start, test, synchronize and prolonged operation in parallel with the
main power generator shall be provided. The emergency diesel generator shall capable of
continuous parallel operation with the main power generators for weekly on load testing and
maintenance.
The Emergency Power Generator itself shall have battery start system and hydraulic start
system as primary and secondary starting facilities respectively.
The final rating of the emergency diesel generator shall be selected to cater for the following
criteria, but not limited to these items:
1. Able to support all the process and utility emergency loads
2. Able to power up all life support systems
3. Able to support the essential Living Quarters (LQ) loads
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4. All Black starting loads (for starting-up one main power generator)
8.3
Synchronization:
The UCPs of the GTG#1, GTG#2 and EDG shall be provided with automatic and manual
synchronizing.
Synchronizing schemes shall be provided for the circuit breakers associated:- 6.0kV main gas turbine generator 1 circuit;
- 6.0kV main gas turbine generator 2 circuit;
- 400V EDG incomer Circuit Breaker and 400V Normal Supply incomer circuit Breaker of
essential LV switchboard.
The scheme shall include the use of AUTO/MANUAL/OFF synchronizing selector switches
provided to meet the synchronising requirement.
8.4
Power Supply Monitoring and Control System (PSMCS)
PSMCS system (supplied as part of the LV switchboard/MCC package) shall be capable of
performing at least the following functions and to have master control of the main power
generators:
-
-
-
Generator Output Control

Fixes steady state voltage and frequency to preset adjustable levels

Shares active and reactive load between interconnect sets

Allows sets to be selected for base load control

Automatically compensates set capability according to fuel type and inlet air
temperature
Engine Control

Automatically starts and loads sets due to operator initiation or detection of low
spinning reserve

Automatically offloading and stops sets due to operator initiation or high spinning
reserve
Load Feeder Control

-
Synchronising

-
Automatic synchronizing of multiple sets across the bus sections
Communication

-
Initiates load sharing to avert cascade failure of the generation system in the
event of one generator being overloaded.
Transfer of PSMCS specific data for display on DCS through dedicated
redundant RS 485 serial link with MODBUS protocol.
Human Machine Interface

Industrial PC based interface acting between GCP and operator during both
commissioning (set-point configuration) and normal operation (control
commands, status & alarm annunciation)

Display on-screen, monitored events and mimic diagram of key components
under the GCP sphere of influence
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
Power Generation & Distribution System Sequence of Event Recording, data
logging and archiving
Interface with the generator GCP shall be hardwired for analogue signals and for rapid
initiation/execution. Serial link data communication may be deployed if speed of data
transmission is not necessary.
The PSMCS shall be a stand-alone system with dual redundancy for critical hardware e.g.
controllers and data storage.
Failure of the PSMCS shall not cripple the operation main power (plant) generators.
8.5
6.0kV Switchgear
The 6.0kV Switchgear shall be designed and constructed in accordance with the Specification
for HV Switchgear (1014-BKTNG-EL-SP-0001) and Datasheet for HV Switchgear (1014BKTNG-EL-DS-0001).
The type tested HV Switchgear shall be totally sheet metal enclosed, free standing, floor
mounted panels of single front, bottom cable entry and fully compartmentalised arrangement.
Facility for future extension at both ends shall be provided.
Ingress protection shall be to IP 32 (min.) per IEC 60529.
Incomer /outgoing feeders shall be withdrawable VCB. All switching devices shall be of
withdrawable type. Each incoming and outgoing feeders shall occupy a single bay.
ESD signals and emergency stop button for motor feeder in switchboard/MCC will be required
if necessary.
Each main incoming feeder shall be rated with 25% spare current carrying capacity.
The HV Switchgear shall be fully tested and certified for a fault and duty rating by an
approved independent international testing laboratory.
The Switchgear shall interface with the Power Supply Management and Control System
(PSMCS), which is described in Section 8.8, by serial link.
All start/stop commands, measurement/status/alarm reporting capabilities from the HV
Switchgear can be realisable by the PSMCS.
8.6
Distribution Transformer
Distribution transformers shall be double copper wound “cast-resin” type units and designed
and constructed in accordance with the Specification for Distribution Transformer (1014BKTNG-EL-SP-0004) and Datasheet for Distribution Transformer (1014-BKTNG-EL-DS0004).
Distribution transformers shall be provided with louvered factory-installed safety enclosure
with minimum ingress protection of IP23.
Passive protection against thermal overload shall be by winding embedded RTD’s that are
wired to a local detection relay for interfacing with the primary circuit breaker feeder protection
relay located at HV switchgear.
The distribution transformer base-rating shall be derived from natural cooling (i.e. AN);
however transformer cooling fans shall be provided and activated automatically in case of
high winding temperature detected.
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Transformer configurations are as follows:
Primary system
:
6.0kV, 50 Hz, 3-phase, 3-wire
Secondary system
:
420V, 50 Hz, 3-phase, 4-wire
Neutral wye point
:
Solidly grounded
Winding insulation /
temperature rise
:
Class F / Class B
Method of cooling
:
AN (however cooling fans shall be provided for forced cooling
under abnormal ambient conditions)
Vector group
:
Dyn11
Tapping
:
Manual, off-circuit, 5 steps at ±2.5 % steps
The distribution transformers shall be installed in a pressurized /force-ventilated transformer
room and shall be suitable for continuous operation at full load (under site conditions).
8.7
Neutral Grounding Resistor
Facilities shall be provided to earth 6.0kV generators via a grounding resistor designed to limit
the generating system earth fault current to a maximum of 400A. The NGR shall be capable
of flowing the 400A earth fault current for the period of 10 seconds without sustaining damage.
The neutral of each main power generator shall be connected to their dedicated NGR.
During normal operation both generators’ star-points shall be grounded through the NGR.
The earthing resistor shall be the rustless-unbreakable grid type in protected enclosure with
minimum ingress protection of IP 23.
8.8
400V Switchboard/MCC
The 400V Switchboard and Motor Control Centre shall be designed and constructed in
accordance with the Specification for LV Switchgear and MCC (1014-BKTNG-EL-SP-0002)
and Datasheet for LV Switchboard/MCC (1014-BKTNG-EL-DS-0002).
Low voltage type tested factory-built assemblies shall be completely metal enclosed, front
access, self-supporting, with bottom cable entry and fully compartmentalised multi-cubicle
assembly of heavy industrial type. It should be “fully withdrawable and modular”, and internalseparation shall be based on Form 4b or Form 3b, Type 2 construction (minimum standard.
The floor or deck-plate (below the switchboard) shall not be considered as being part of the
enclosure.
Motor starters and outgoing feeder modules shall be ‘full-width’; space saving quarter and half
compartments will not be acceptable.
The low voltage assemblies shall be designed for continuous operation at full load for at least
40,000 hours without maintenance that would require the main busbars and the distribution
busbars (dropper system) to be de-energized. Unless specifically stated, all LV Switchboard
shall be indoor installed low voltage factory built type-tested assemblies (TTA).
All main and dropper busbars shall be fully insulated.
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The degree of ingress protection per IEC 60529 shall be:
For indoor use
IP41(min.)
For outdoor use
IP56(min.)
All structural work shall be adequately protected against corrosion. Frame and partitions may
be of galvanised steel without the need for a further paint coating. Those parts/covers
requiring painting shall be properly pre-treated before the final coat(s) of oil resistant finishing
paint is (are) applied.
Assemblies shall comprise one or more sections of busbars to which incoming and outgoing
units are connected. Busbar sections shall be linked through sectionalizer units. These
sectionalizer units shall fully withdraw-able and be identical in construction/make to those of
the incoming feeder “Air Circuit Breaker”.
The maximum continuous allowable current rating of both incomer feeders/bus couplers and
main busbars shall be 5000A nominal. Forced cooling of LV switchboard is not acceptable.
LV switchboard incomer units shall be ACB and managed by an intelligent feeder protection
relay (FPR).
All motor starter modules shall comprise MCCB/contactor/motor control unit (MCU). Nonmotor feeders rated up to 400A shall c/w MCCB, non-motor feeder rated above 400A shall
c/w ACB/feeder control unit (FCU).
Each main incoming feeder shall be rated with 25% spare current carrying capacity.
Fully equipped spare compartments shall be provided in each switchboard. The number of
spare compartments shall be 25% of each size of outgoing units subject to the minimum
number being 1 for each size.
Unless specifically stated otherwise, all LV induction motors shall be started-up by DOL
method. LV motors rated 100kW and above shall be assisted started by electronic soft
starters.
All motors shall be protected with intelligent MPR. The MPR shall have LCD panel as HMI
either as integrated into the MPR.
Motor earth fault protection to be provided for all motors.
Motors may be remotely controlled (for start/stop) from the DCS through the IMCS [see 8.8
below], and tripped from ESD (in case of exercising emergency shut-down).
All package equipment motors which have Unit Control Panels (UCP), shall be remotely
controlled by hard-wired start/stop command signals and status signals. Shutdown/trip
originating from ESD shall only be effected through one hardwired signal from the ESD to the
Unit Control Panel.
Push button type local control station (LCS) with running indicating light shall be provided for
all electric motor. An ammeter shall be provided on LCS for motor rated ≥ 30kW. Local
Control Station (LCS) with ammeter shall be provided for submersible motors and those
motors which are not visible to the operator. Depending on the application (whether control by
DCS or by package UCP), LCS configuration for motor starters shall either be Off-O-On type,
or H-O-A type.
Electrical interlock shall be provided in the LV Switchboard/ MCC to control the automatic
switching of the incoming ACBs and bus-tie ACBs during transfer supply.
At anytime, parallel incoming power supplies are not allowed except during power supply
transfer from incomer A to incomer B (and vice-versa) during maintenance, from emergency
to normal supply and during emergency power generator weekly on load testing.
During emergency power generator weekly on load testing, it will be parallel supply between
main power generator and emergency power generator supply.
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In any case, bypass key operated switch shall be provided for platform operator to bypass
parallel interlock when it is necessary.
Outdoor installed factory built assemblies of motor starters and feeders shall be type-tested
assemblies (TTA) in the form of weatherproof switch-racks may be implemented for remote
non-process/non-production/non-critical applications (e.g. at FDP) and installed in nonhazardous area.
The configuration and controls topology associated with switch-racks shall be similar to the
LV switchboards installed indoors.
8.9
Integrated Motor Control Centre (IMCS)
The Integrated Motor Control Centre (IMCS) shall be a system complete with microprocessor
based intelligent motor/feeder protection relays, control and monitoring system for both HV
and LV switchboards, and other electrical systems (e.g. UPS).
The IMCS shall be part of the 400V Switchboard/ MCC package order and both equipment
manufacturers must be approved by the COMPANY.
Each motor circuit and outgoing feeder shall be controlled by the microprocessor based Motor
Control Unit (MCU) and Feeder Control Unit (FCU). The microprocessor based interface
device, Central Control Unit (CCU) shall have a serial link connection for communication with
MCUs and FCUs. This connection shall be of the “daisy chain” type thus ensuring that even if
the communication link is broken at a single point, all devices are still accessible from the
CCU. If necessary, IMCS shall be capable of interfacing with intelligent FPR via a separately
configured serial link network – so as to link the FPR to the IMCS CCU.
DCS communication with the Integrated Motor Control System (IMCS) shall be via redundant
RS 485 serial link with MODBUS protocol.
Remote start/stop of motors from DCS shall be provided as required.
DCS shall also receive status and alarm signals for each motor.
The motor standby/run status and alarm shall be displayed at DCS and at IMCS Operator
Work Station (OWS).
Motor trip command from the ESD shall be hardwired to the 400V Switchboard/ MCC directly.
The trip relays required for the ESD signals shall be available in the 400V Switchboard/ MCC.
When the trip command is active, motor shall not be possible to start either from DCS or from
the LCS in the field.
Electrical main circuit breakers’ open/close status shall be relayed to the DCS through the
IMCS.
Other miscellaneous electrical system I/Os which are not available from IMCS, such as
battery and charger alarms, UPS common alarms, etc. shall be hardwired to the DCS.
8.10
Electric Motors
Electric motors shall be designed and constructed in accordance with the Specification for
Electrical HV Motor (1014-BKTNG-EL-SP-0009) and Specification for Electrical LV Motor
(1014-BKTNG-EL-SP-0008) and the relevant Datasheet for Electrical HV Motor (1014BKTNG-EL-DS-0009) and Datasheet for Electrical LV Motor (1014-BKTNG-EL-DS-0008).
Electric motors shall generally be delivered as part of a mechanical equipment package, i.e.
mounted on the same skid or base plate as the driven equipment. For hazardous area
installation, motors shall be suitably certified.
All electric motors shall be of squirrel cage, totally enclosed fan cooled (TEFC) induction type,
continuously rated for duty type S1, and generally suitable for direct-on-line starting. Motor
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enclosure and terminal box shall have IP56 as minimum ingress of protection, but for
submerged electrical motors IP68 shall apply.
Motor winding shall be made from copper and insulated to insulation class F with maximum
temperature rise allowable for class B. However, winding insulation class for submersible
motor shall be as per Manufacturer’s standard.
Electrical motors, as a minimum, shall be provided with proper sealing of motor shaft and
cable entry.
In general, motors with soft starter or variable speed drivers shall be provided with thermistor
PTC (or RTD) detectors, for winding temperature monitoring, wired to starter panel.
VFD driven motors shall have additional nameplate stating that the motor being suitable for
hazardous location duty while being driven by a matching VFD, and whatever operating
conditions to be observed.
Motor anti-condensation heater shall be provided for all motors ≥ 15 kW. Motor anticondensation heater shall be controlled from the motor starter main contactor auxiliary
contact – to energise when motor is not running.
VFD controlled motors shall have safety switch installed for local isolation of motor feeder
from upstream VFD.
For HV motors, a heater On/Off safety switch shall be employed wherever motor space
heater is powered from a source that is external to the motor starter and shall be installed
adjacent to the motor’s Local Control Station (LCS).
The location of the Local Control Station (LCS) and / or safety switch shall be on the opposite
side of the motor to the main terminal box. LCS enclosures located at open area exposed to
direct sun ray and rain shall be made from 316L stainless or aluminium alloy (LM6). Polyester
Glass Reinforced Fibre (GRP) can also be used as alternative material for LCS enclosures
installed in shaded areas.
8.11
Variable Frequency Drive (VFD)
Variable frequency drives shall be employed where either speed-control of motor driven
equipment is necessary or to regulate the high starting current encountered for exceptionally
large LV motors.
For applications in hazardous locations, the VFD and driven electric motor shall be matched
and the electric motor shall be designed, constructed and certified for hazardous area
operation.
The combination of VFD and motor shall be specified to be supplied from same
Manufacturer/Supplier – in order that single-point responsibility is ensured.
Depending on required motor rating and overall power system configuration, voltage levels for
VFD/electric motors may either be at LV or HV.
Current harmonic distortion caused by the rectifier input current of VFDs shall be controlled
and mitigated in order that system voltage harmonic distortion is kept within 5% and 3% - for
total harmonic distortion (THD) and any single harmonic respectively.
VFDs of motors driving process equipment shall have direct communication with DCS for
start/stop commands, speed raise/lower commands, common fault alarms, and stand-by
status.
Either hard-wire signaling or serial link data communication between DCS and VFD may be
acceptable. However, tripping signal from ESD shall be hardwired to trip the upstream
breaker of the VFD.
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8.12
Uninterruptible Power Supply (UPS)
8.12.1 AC UPS
AC UPS systems shall be provided for powering up vital loads.
The AC UPS system shall be designed and constructed in accordance with the Specification
for AC Uninterruptible Power Supply (1014-BKTNG-EL-SP-0005) and Datasheet for AC
Uninterruptible Power Supply (1014-BKTNG-EL-DS-0005).
UPS system shall be provided to power vital electrical loads such as LV Switchboard/MCC
control supply, helideck lights, aviation obstruction lights, generator control panel, compressor
control panel, telecommunication systems, and instrument systems like ESD/FGS/DCS
workstation and other vital package control panels.
The selection of either 3 phase or 1 phase output AC UPS shall depend on installed kVA
estimated during the course of equipment sizing.
The AC UPS installation shall consist of 2 x 100% UPS units (connected in Parallel
Redundant configuration each with its own charger, battery, static changeover, Inverter) with
a common maintenance by-pass transformer, common maintenance bypass switch and a
common AC UPS distribution panel.
A static by-pass shall be provided to allow the automatic changeover of the output supply
from the inverter to a stabilised supply from a bypass-transformer when both of rectifiers fail.
A maintenance by-pass shall be provided via a changeover switch to allow manual
changeover of the output supply from inverter to isolation of the UPS for maintenance.
The AC UPS shall be suitable for operation with the following requirements:
Input supply
:
400V, 50 Hz, 3-phase, 3-wire
Output voltage (depending
on installed kVA)
:
Either 230V, 50 Hz, 3-phase, 3-wire, or 230V, 50 Hz, 1phase, 2-wire
The AC UPS unit shall be of free standing, sheet metal, front access with floor mounted panel
suitable for mounting by bolts. The enclosure degree of protection shall be IP 31 minimum.
The UPS shall be installed inside the Emergency Switchgear/MCC room. Battery bank shall
be installed on the steel rack mounted inside the battery room.
Battery circuit breaker shall be provided inside the battery room to isolate the battery bank
from the battery charger and load bus. The breaker shall be installed in explosion proof
enclosure. The circuit breaker shall have tripping facility from FGS/SDS and manual/remote
tripping.
The battery circuit breaker shall be manually close only.
8.12.2 Batteries
Battery banks installed in the battery room for AC UPS shall preferably be in single strings of
“gel type” Valve Regulated Lead Acid (VRLA) cells. Battery room temperature should be
maintained at 20oC, in order to maintain optimum performance and ensure full design life.
Batteries shall be sized with a 25% ageing factor and a further 10% contingency shall be
added.
Batteries mounted in indoor battery rooms shall be as per specified on the technical data
sheets. All cell containers shall have shock-absorbing, non-conductive, heat resistant
containers, flame retardant and sealed covers to provide a permanent leak-proof unit.
The batteries of UPS units shall be rated to energise the relevant loads for not less than:
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8.13
45 min.
-
for switchboards, packaged equipment unit control panels, and all other
systems like Metering panels, Sub-sea controls and etc
1 hours
-
for shutdown system, ESD.
1 hour
-
for Distributed Control System, DCS.
3 hours
-
for Fire and Gas System, FGS
3 hours
-
for PABX, VSAT communications equipment
3 hours
-
for PA/GA system and status lights
45 min.
-
for non-SOLAS communication equipment e.g. LAN, CCTV and etc.
24 hours
-
for SOLAS (Safety of Life at Sea) communications equipment
12 hours
-
for Aviation Obstruction Light, Illuminated Windsock,
1 hour
-
for helideck lighting (flood lights, perimeter lights)
96 hours
-
for Navigational Aids marine lanterns, and beacon
Bus duct
Cast resin bus ducts shall be used in place of high “ampacity” feeders requiring multiple runs
of single or multi-core cables e.g. feeders between transformers and LV switchgear.
The bus ducts shall be designed as a system consisting of straight lengths, bends, elbows,
break-outs, and terminal (flexible connectors).
600V grade, 3-phase, 4-wire, 50Hz Bus duct assemblies shall be provided for interconnection
between the LV side of each of the Power Distribution Transformers and the corresponding
LV Switchgear.
The connection bus ducts shall be designed and constructed to IEC 61439-2 with degree of
ingress protection of IP 68 for both indoor and outdoor portion of the bus ducts.
Bus ducts shall comprise of tinned annealed hard drawn copper busbars self extinguishing
with homogenous cast resin insulation, rigidly supported in a totally enclosed and nonventilated metal enclosure. The bus ducts shall be flame retardant and shall consist of 3
phase and neutral busbars complete with internal earth bus. Busbars shall be insulated over
their entire lengths.
The temperature rise of busbars inside the bus ducts shall not exceed the permissible values
stipulated in IEC 61439, while carrying the rated full load current. Neutral bus shall have
continuous current ratings of 100 % of the phase bus.
Busbars shall be sized, braced and supported to withstand the mechanical and thermal
stresses of the rated short circuit current of the Transformers, Switchgear to which the bus
ducts are terminated. Bus ducts shall have short time ratings not less than the upstream
circuit breakers.
Bus duct access openings shall be provided at each end of bus ducts for testing and
commissioning purposes.
The busduct system design shall carry type test certification from a recognized independent
testing laboratory for short-circuit withstand capability
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8.14
Electric Power and Control Cables
Electric cables to be installed shall be designed and constructed in accordance with the
Specification for Electrical Cables (1014-BKTNG-EL-SP-0010).
Cables shall be stranded (Class 2), tinned annealed copper conductor according to IEC
60228.
Where more flexible cable bending is required, and upon the approval from the COMPANY,
Class 5 cables shall be employed where needed.
For LV distribution system, maximum copper conductor sizes for multi-core cables shall be
240 mm2 and 185 mm2 for power feeders and motor feeders respectively.
Maximum copper conductor size for single core cables shall be 630 mm2.
For HV distribution system, maximum copper conductor size for multi-core cables shall be
185 mm2.
Where single run cabling is insufficient, multiple cable of up to two runs and four runs for
multi-core and single-core cabling may be employed.
Minimum cable cross-section for power and lighting/control cables shall be 2.5mm2 and
1.5mm2 respectively.
Cables for normal services shall be flame retardant to IEC 60332-3 Cat A while those for
critical services shall be flame retardant and fire resistant to IEC 60331.
Penetrations through the fire rated walls, between hazardous and non-hazardous area and
also when external cables enter package enclosures, these entries shall be sealed with fire
rated multi-cable transits (MCT).
In general, cables shall be suitable for the design conditions, fully filled with non-hygroscopic
fillers, fully sealed to avoid the ingress of water and gas, and meet the minimum bending
radius without the formation of ripples on their outer cover. Unless otherwise specified, all
cables shall be braid armoured. Bedding and outer sheath material of cables shall be LSZH
type. Cable for vital services shall be fire resistant together with flame retardant in accordance
with IEC 60331 and IEC 60332 respectively.
Single core cables pertaining to 3 phase circuit shall be laid together in trefoil formation and
held together by “certified short circuit withstand” cable cleats and separated from multi-core
cables.
Individual conductors shall be based on new colour coding based on BS 7671 Amendment
No.2 and IEC 60446.
All cable armouring shall be tinned copper wire braid.
Single run of cable from ladder/tray shall be supported by painted steel flat bar.
8.14.1 General Application
EPR/CWB/LSZH , flame retardant and with an oxygen index of not less than 30, temperature
index of not less than 260oC and type tested in accordance with IEC 60332-3 Category A
(reduced propagation) and acidic emission of max. 17% (by weight) in accordance with IEC
60754.
Cable outersheath shall be thermoset compound, SHF2 (as per IEC 60092-359).
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8.14.2 Living Quarters
EPR/EMA/CWB/EMA or EPR/EVA/CWB/EVA for multicore, low smoke zero halogen (LSZH),
flame retardant in accordance with IEC 60332-3 category A.
EPR/EVA low smoke zero halogen (LSZH), flame retardant in accordance with IEC 60332-3
category A for cable running in conduits.
8.14.3 Critical Services
Mica glass tape (MGT) primary insulation, EPR insulated, fire resistant in accordance with
IEC 60331, withstand with temperature of 750oC for three hours, low smoke zero halogen
(LSZH), flame retardant in accordance with IEC 60332-3 category A (reduced propagation).
8.14.4
VFD Cables
VFD motor feeders shall be 3-core cables, constructed and rated for VFD applications; single
core cables shall not be used for VFD application.
8.15
Sizing of Cables
The sizing of cables shall take the following into consideration:

The maximum continuous rms load current

Derating factor due to grouping of cables

Derating due to maximum ambient air temperature

Voltage drop

The length of cables
The short circuit current withstand capability shall be consider for main incomer and HV cable
sizing. The short circuit current withstand capability of cables shall be determined in
accordance with:

The rated short circuit breaking current of the source switchboard

The fault clearance time associated with the operation of the primary protection
In general, the A.C. electrical system should be designed such that the voltage drop at normal
operating load conditions shall not exceed the following limits:
Main Feeders
1 to 2%
Motor Feeders
2 to 3%
Lighting Panel Feeders
2 to 3%
Lighting Branch Circuits
2 to 3%
Total voltage drop from main switchgear to the furthest point shall not be more than 5% based
on continuous maximum current loading and rated voltage.
The voltage drop in DC cable shall be consistent with the minimum system voltage at the
distribution board and the minimum equipment operating voltage but should not exceed 5% in
any case.
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8.16
Cable Installation
8.16.1 General
The whole of the cabling, i.e. cabling for the electrical, instrumentation and
telecommunications systems shall be designed to form one integrated system, so as to
ensure suitable cable routing and adequate segregation (for reasons of safety, circuit integrity
and interference prevention) of the different cable types.
Cable support system may comprise cable racks, cable trays, cable ladders and “open”
rigid/flexible conduits. Individual cables may be fixed directly to the main structures, walls,
ceilings or columns by means of proper fixing and supporting materials. Generally, cable
splicing is not permitted, and if unavoidable - requires COMPANY's approval.
MCT shall be used for cable penetration
8.16.2 Laying Pattern
Within the power cable category, HV multi-core cables may be laid in one layer touching, and
LV multi-core cables in up to a maximum of two layers touching and with the applicable group
rating factor applied.
Cables should be segregated and suitably identified in the applicable cable category, i.e.

HV Power Cable

LV Power and Control Cable for non-instrument control

Instrument cables
Individual cables emerging from floors shall be protected against mechanical damage by
means of galvanised steel pipes.
Single core cables emerging from floors shall be protected and sealed by the use of multicable transits (MCT).
Grouped cables emerging from floors and MCT shall be protected collectively by a properly
designed metal shield or duct in such a way that heat dissipation from the sustained load
carrying cables is not hampered. The propagation of fire from one space to the other shall be
prevented by the proper sealing of openings around cables.
If cables are to be routed through restricted openings, care must be taken to ensure that fire
is not intensified or readily channelled along the cable route.
Cables shall be fixed to ladders or trays using Nylon sheathed stainless steel cable ties.
8.16.3 Cable Marking/ Numbering
Cables shall be tagged with pre-printed cable numbers similar to the Grafoplast SI2000
system at each ends and both side of cable penetration. Cables shall also be numbered
where they branch off from a main route.
8.17
Lighting System
The lighting system shall consist of normal lighting fed by normal lighting distribution boards
while emergency lighting will be powered by emergency lighting distribution boards. HID
floodlights and well-glass lights will be used for general lighting. The maximum usage of the
floodlight shall be made for open areas; glare control shall be exercised. Floodlights and
wellglass lights with either Ex ‘d’ or Ex’de’ certification and IP56 (min.). The lamp wattage will
depend on the area to be lit.
Fluorescent luminaries will be used, where necessary, for local lighting of operating areas
requiring higher illumination level which will be difficult to achieve using floodlights.
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Fluorescent luminaires shall be used for escape route lightings. For escape lighting, the same
type of luminaires shall each be equipped with an internal self contained backup
battery/charger.
The location and mounting of luminaries shall take account of efficient illumination,
accessibility of luminaries and convenience of servicing. Luminaries shall not be mounted
above machinery having exposed moving parts. Adjacent luminaires shall, as far as
practicable, be on separate circuits. Lighting circuits shall also be arranged to avoid
stroboscopic effects.
Lighting circuits shall be single phase and neutral or three phase and neutral, protected with
maximum 20A MCBs, but not be loaded higher than 16A. Lighting distribution boards shall
include minimum 15% spare outgoing circuits.
General lighting luminaries shall comprise of the following types:

For outdoor locations or in enclosed space without air conditioning, housings of lighting
luminaries shall be of either Stainless Steel (SS316L) material or Aluminium Alloy (LM6)
material; suitable for Zone 1 application.

For indoor locations with air conditioning, fluorescent luminaries housings shall be made
of painted / powder coated steel, Glass Reinforced Polyester (GRP) luminaires may be
used in damp areas.

Recessed luminaires fixed to ceiling in Living Quarters shall be certified with minimum
B15 fire rating to be compatible with the ceiling installation.
Light sources for outdoor lighting shall be tubular HID lamps of high pressure sodium (SON)
and/or metal halide (MBI), and T8 tubular tri-phosphor fluorescent lamps.
Light sources for indoor lighting shall be by the use of T8 tubular tri-phosphor fluorescent
lamps, halogen lamps and LED lamps. The use of compact fluorescent (PL) lamps should be
explored and should be used indoors, especially in the LQ.
The platform normal lighting system shall remain switched on 24 hours. The lighting
installation in control rooms shall be designed so that ceiling lighting groups can be switched
off independently to suit operators’ needs.
The minimum illumination levels, measured at the working plane or 0.8m above the floor level
in the horizontal plane shall provide the illumination levels based on the following
requirements:
Location
Lux
(a) Normal Lighting
Offices
Recreation Room
Bedrooms
Hallways, Stairways, Interior
Walkways, Stairways, Exterior
Bath
Galley and Mess Hall
Electrical Control Rooms
Storeroom
Work Shops
Compressor, Pump and Generator Buildings, General
Entrance Door Stoops
500
300
200
100
20
100
300
300
100
700
300
50
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Open Deck and Well Head Areas
Central Control Room & Instrument Control & Equipment Room
Telecom Equipment Room / Radio Room
Battery Room
Outdoor process areas
Outdoor non process areas
Laboratory
50
400
400
200
150
75
400
(b) Emergency Lighting
When powered by internal back-up battery:
Stairways
Offices
Exterior Entrance
Compressor and Generator Rooms
Electric Control Rooms
Open Deck Areas
Lower Catwalks
20
10
10
50
50
10
20
The illumination levels for escape route lighting where lighting is provided by battery powered
luminaires, will be 1.0 lux in accordance with NFPA 101.
8.17.1 Normal Lighting
Luminaires with fluorescent and HID (HPS/MBI) lamps shall be used as the main light source
for outdoor area.
Luminaires with fluorescent lamps shall be used for indoor areas.
HID floodlights shall be provided where illumination for large and open areas is required such
as main deck, wellhead, laydown area and boat landings.
Outdoor areas with limited clearance such as walkways, wellhead area, etc. may use
fluorescent fittings. The lighting shall be provided by pendant, wall, ceiling or stanchion
mounted type.
Indoor lighting shall be controlled by individual wall mounted switches located in each area or
room near the exit.
Normal lighting shall be fed from normal lighting distribution board and shall cover about 70%
of lighting requirements.
8.17.2 Emergency, EXIT and Escape Lightings
Emergency lighting luminaries shall be installed at strategic locations including control rooms,
switchgear room, instrument room, living quarters, escape routes and areas where required
for safety reasons.
Emergency lighting shall be backed-up by supply from emergency power generator.
EXIT lights with built-in back-up battery shall be installed for marking exit doorways and long
escape routes; they shall remain continuously lighted.
Emergency lighting shall cover about 30% of lighting requirements.
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Part of the emergency lighting shall function as escape lighting and be located such as to
illuminate the escape routes, ladders and walkways to allow safe movement of personnel to
the muster points, lifeboats, etc.
Escape lighting shall be fed and equipped in the same fashion as the rest of the emergency
lighting except with internal self contained battery back-up for a 90 minutes autonomy time.
The battery shall be recharged within six (6) hours.
Escape luminaires shall be installed at the following locations:

Every exit doorway

Every sleeping cabin

External escape ways (stairways and walkways)

Internal escape ways (escape routes in modules or deck areas, accommodation area
corridors, and galley)

Embarkation areas (access to helideck and survival craft stations)

Muster areas
Escape luminaires installed in sleeping cabins shall only illuminate on loss of the a.c. supply
to the integral battery charger.
Escape type lighting shall be provided in the living quarters to provide escape lighting in a
smoke situation.
The minimum required level of illumination is 1 lux along the centre line of an escape route.
Escape lighting and battery back-up emergency lighting shall have Ex ‘e’ or Ex ‘d’ certification.
Fixed emergency floodlights shall be provided under boat landings, liferafts, life boats area,
and mustering area via the emergency power supply.
8.17.3 Hand Lamps
Rechargeable hand lamps will be provided for all areas where operating personnel may be
present at all times the followings:

Control rooms

Switchgear rooms

Instrument rooms

Workshops

Maintenance supervisor room

Platform supervisor room
At least one hand lamp (complete with charging station) should be installed on the inside of
each exit door way.
Each hand lamps shall comprise a fixed wall mounted battery charger and shall be Ex ‘e’
certification. The unit shall be kept on float when not in use and fed from emergency lighting
distribution board. The battery shall be rated to energise the hand lamp for not less than 5
hour.
8.18
Navigational Aids
The navigation aids system shall be supplied from a dedicated DC UPS and control system
complete with 96-hour back-up battery bank. This system shall comply with Specification for
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Navigational Aids System (1014-BKTNG-EL-SP-0007), and Datasheet for Navigational Aids
System (1014-BKTNG-EL-DS-0007).
8.18.1 Marine Navigational Lights
All equipment and all it accessories shall be suitable for areas classification (normally Zone 1).
Navigational Aids System shall be provided to comply with the statutory requirements. Main
white navigation lights shall be provided in accordance with the requirements of the
International Association of Lighthouse Authorities (IALA).
Marine lanterns shall be provided at the corners of the platform and on the link bridge.
Flashing white light exhibiting Morse code 'U' signal every 15 seconds shall be provided to
mark the furthest corners of the platform such that at the horizontal extremities of the platform
is visible to the approaching vessel.
The marine navigational aids system shall operate from the Navigational Aid Central Control
Panel (NCCP).
A dedicated 24V DC UPS system for the navigational aids system, comprising at least the
following main components shall form part of the package:

1 x 100% Rectifier (charger)

1 x 100% Battery bank
The NCCP shall be housed in an Ex‘de’ enclosure with a minimum ingress protection of IP56
(min.); battery bank shall be housed in Ex’e’ battery box.
The 24V DC UPS system for navigational aids shall never be tripped even under gas
conditions.
Battery backup time shall be at least 96 hours or 4 days continuous.
8.18.2 Foghorns
Foghorns shall be provided for deployment during periods of poor visibility.
Installed locations of the foghorns shall enable the blasts to be in unison, heard from all
approach directions to the CPP/FDP complex. The foghorns shall not be installed close to the
LQ.
Activation of the foghorns shall be automatic on detection of poor visibility at CPP/FDP
complex.
8.18.3 Aviation Obstruction lights
Red coloured aviation obstruction lights shall be installed on the pedestal crane and flare
boom and any tall structures, near/below the flight path, which are considered as potential
obstructions to aviation. The lighting luminaires shall be omni-directional with a minimum
intensity of 10 candelas and powered from the platform central AC UPS system with battery
backup time of 12 hours.
8.18.4 Helideck Lightings
Helideck lighting shall be provided in accordance with International Civil Aviation Organisation
(ICAO) or CAP 437. Helideck shall be lighted up with green lanterns along the perimeter of
the landing area, together with helideck floodlights.
Helideck lighting shall be designed such that glaring to the pilot and hazard to helicopter
landing is avoided. Power supply to the helideck lighting shall be from the AC UPS power
supply. Battery backup time shall be 12 hours.
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Status lights (wave-off) and illuminated windsock shall be installed at the helideck.
8.19
Socket Outlets
Power and convenience socket outlets installed outdoors shall be suitable for Zone 1 areas,
fitted with padlocking facilities and the distribution circuit breakers associated with these
socket outlets should be trip interlocked with the fire and gas/shutdown system.
In non-hazardous indoor areas, convenience socket outlets of the industrial type shall be
installed where required.
Domestic pattern convenience socket outlets shall only be fitted in the accommodation areas.
Power and convenience socket outlets shall be mounted approximately 0.3 to 1.5 m above
grade level, either on a free-standing support, on structural steelwork or on a building wall.
Outgoing circuit breaker for socket outlets and small power circuits shall be equipped with
earth leakage protection (current operated ELCB or RCCB) with the following sensitivity:
3 phase – 100mA;
1 phase – 30mA
8.19.1 Topsides Application
Sufficient power and convenient socket outlets shall be provided to enable maintenance to be
carried out. Socket outlet circuits shall be protected with earth leakage protection in the
distribution board or MCC and shall have facility for FGS/SDS remote tripping
Power socket
:
32A (& 63A), 400/230V, 50 Hz, 3-pole + neutral + earth
Convenience socket
:
16A, 230V, 50 Hz, 2-pole + earth
Three phase socket outlets shall be located/rated to suit anticipated fixed, portable and
temporary equipment, etc. plus 1 off in the electrical workshop rated to suit all anticipated
testing.
At least 4 nos. of 1-phase sockets and 2 nos. 3-phase sockets shall be installed per deck
layout.
8.19.2 Living Quarters
Minimum of two twin convenient socket outlet shall be provided in each room and four twin
socket outlets for each office.
Additional socket outlets shall be provided for larger rooms and special function rooms such
as electrical room, equipment control room, pantry and laundry to suit special requirements.
No more than four socket outlets shall be connected to each circuit.
Socket outlet shall be 16A, 230V, 2-pole + earth type, and 32A, 400/230V, 400/230V, 3-pole +
neutral + earth type.
All socket outlets shall be protected by ELCB circuit breakers.
8.20
Multi Cable Transits (MCT)
Penetrations through the fire rated walls and between hazardous and non-hazardous areas
shall be sealed with fire rated multi-cable transits (MCT).
Multi cable transits shall generally be installed where cables pass through the following
locations:
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1. rated wall / floor / ceiling
2. Gas tight wall / floor / ceiling
3. Walls between hazard and non-hazardous areas
4. Package Enclosure
Cable shall not penetrate blast and H-rated walls except at the edges. Cable transits shall not
be installed in roof or top entry application. Sufficient multi cable transit frames are to be
installed to allow for approximately thirty (30) % spare capacity for future cables. All open
cable penetrations shall be sealed with fireproof materials. These penetrations shall meet the
requirements of DNV’s Offshore Standard - DNV-OS-D301 “Fire Protection”.
Minimum MCT fire rating shall be 1 hour A60 rated. If the firewall or blast wall is rated for H60
then the MCT installed shall have the same fire rating.
8.21
Cable Glands (stainless steel/ nickel plated brass)
All steel braided armoured cable entries into equipment shall be made by means of suitable
brass double compression cable glands with an armour-clamping feature, with inner and outer
seals providing minimum ingress protection of IP66, ISO metric threads, complete with
locknut and earth tags. Barrier glands shall be used if the cables are not of the effectively
filled type.
Cables shall be terminated, glanded (without shroud) and tested shortly after installation.
Incomplete cable installation shall be properly coiled, identified, supported and capped off to
prevent contamination.
Cable entering equipment which may be removed or replaced for maintenance shall have its
cable looped prior to entry. Cable entry to equipment shall be from the bottom or side and
protected from weathers.
Certified plugs shall be used to blank off all unused entries in certified Ex'e' and Ex'd'
equipment and similar certified adaptors shall be used to match metric glands to non-metric
entries. Entries shall only be made in certified enclosures by the Manufacturer.
Cable glands shall be provided to suit the type of cable and termination box/ enclosure, and
shall be of the appropriate type of protection, e.g. Ex'd', Ex'e'. Effective earth continuity shall
be ensured between the cable armour/braid and the gland plate or the internal earth terminal.
8.22
Electrical Heat Tracing
The electrical heat tracing shall be designed to withstand the highest possible temperature
which can occur under all process condition.
The electrical heat tracing shall be designed based on self regulating/self limiting heater and
shall be suitable for operation in Zone 1 / Zone 2 hazardous location.
The source of electric power to heat tracing circuits shall be from dedicated heat tracing
“isolation transformer” installed inside the heat tracing distribution panel.
Heat tracing circuits shall be individually protected by 30mA ELCB located in the distribution
board. Ammeter shall be provided at each outgoing heat tracing feeders in the distribution
board.
A common fault alarm signal from the heat tracing panel shall be provided to DCS, if any of
the outgoing heat tracing circuits trip out by fault.
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8.23
Junction Boxes
Power and lighting junction boxes for outdoor application, shall be made from electro-polished
316L stainless steel, IP 56 (min.) and certified to EEx’e’.
Indoor junction boxes may be made of high impact resistant, flame retardant glass-reinforced
black polyester with internal ground continuity plate.
All outdoor power junction boxes cable entry shall be from bottom except for lighting junction
boxes where side and/ or bottom entries are acceptable.
Intermediate junction boxes or cable splices are not permitted on power cabling unless
approved in writing by COMPANY. In general, this is only permitted to connect regular power
cable to motor cable e.g. submersible motor.
All package skid interface junction boxes shall be at the skid edge external to any acoustic
enclosure.
An Ex-certified breather/drain device shall be installed in each outdoor enclosure that is
higher than 8 litres in volume.
8.24
Cable Ladder/ Tray
Cable support system shall generally comprise cable racks, cable trays, cable ladders. All
installed rigid cable supports shall be made of Stainless Steel SS316L material.
Galvanised carbon steel and GRP cable support systems shall not be used.
Cable trays and ladders shall be closed with removable top covers allowing adequate
ventilation in situation where:

Mechanical damage to the cables is likely to occur during construction, operations and
maintenance.

Oil or chemical spillage can be expected

Sun shielding against direct solar radiation
Cables trays and ladders shall not be installed in front or over pipes, risers and equipment.
Maximum unsupported span for cable trays and ladders shall be in accordance with
manufacturer's instruction and in no event shall exceed 1.5m and 3 m respectively. Crossing
of open areas and walkway shall be at least 3 m clear.
Cable tray / ladder covers in excess of 300mm shall have supplementary fastening using two
(2) stainless steel bands per length.
A minimum of 15% spare rack, trays or ladders capacity shall be provided.
Maximum side rail height shall be 150mm for ladders and 40mm for trays.
Maximum rung spacing for ladders shall be 300mm.
Vertical separation is required between parallel levels of cable ladder or tray and shall be a
minimum of 300mm. Sharp bends or edges for cable racks / ladders / trays are not permitted.
All cable racks / ladders / trays shall be earth bonded between sections and to welded steel
structures and in no event the intervals shall exceed 25m.
Cable penetrating through decks shall be protected from damage by kick plates. The top of
the kick plates shall be covered or made smooth.
The bending radius of cables shall not be less than that specified by the cable manufacturer.
Cable shall be properly identified per service grade and segregated into groups in according
to the drawings.
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Installed cables shall be fastened by means of Nylon sheathed stainless steel cable tie wraps
in every 3 m for horizontal trays and 1 m for vertical ladders. Supports for cable ladders or
trays shall be painted galvanised carbon steel.
Separate cable ladder / tray shall be provided for HV, LV and DC cables. High voltage cable
ladder shall be mounted as far as possible from instrumentation cable ladder system.
8.25
Conduits and Accessories
Wiring in conduit shall only be used on short runs of 2 metres or less (1 joint), and on
package skids where it is more practical than using armoured cables on trays. Outdoor
conduit/conduit fittings including condulet boxes shall be of rigid epoxy coated galvanised
feraloy. All conduit termination shall have a minimum of five threads fully engaged. Conduit
shall be heavy duty type. Pipe and pipe fittings are not permitted in any conduit installation.
9.0
CONTROL, PROTECTION AND MONITORING
All distribution control, protection and monitoring functions shall be located on the respective
distribution panels and starters. Remote operation of power users (e.g. start/stop commands,
run/stop status and trip alarm for motor starters) shall be through the distributed control
system (DCS).
Variable frequency drives (VFD) shall have their “running” and “stopped” status and “tripped”
alarm indicated on a built-in annunciator (LCD) panel.
Start/stop and ramp-up/ramp-down commands to VSD shall be hardwired from the DCS.
If required, VFD shall also have the capability to relay status & alarm, load current, speed and
other critical information to the DCS.
The electrical system shall be equipped with automatic protection which shall provide
safeguards in the event of electrical equipment failures or system mal-operation.
The selection and specification of switching and protective devices, control circuits and
associated auxiliary equipment shall be in accordance with international standards.
Notwithstanding these requirements, automatic protective systems shall be designed to
achieve selective isolation of faulted equipment with minimum delay. In any event this shall be
within a time corresponding to the short circuit current withstand capability of equipment,
system stability limits and the maximum fault clearance times.
All incomers, transformer, and main ACB/VCU/VCB outgoing feeders are controlled and
protected by intelligent Feeder Protection Relays (FPR).
All protection devices related to generator/driver protection will be provided by generator
packager which form part of each generator UCP.
9.1
Generator Feeders
The generators incoming feeders shall have the following protective and metering devices as
a minimum. The protection and metering device shall be multifunction electronic type.

Differential relay (87)

Reverse power relay (32)

Synchronising check relay (25)

Voltage restrained overcurrent relay

Phase balance current relay (46)
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
Overvoltage relay / Undervoltage relay (59/27)

Over/under frequency (81 O/U)

Lockout relay (86)

Overcurrent relay (50/51)

Over temperature protection (49)

Earth fault protection (50N/51N)

Negative phase sequence relay (47)

Trip coil supervision relay (TCM)
Metering devices includes ammeter with selector switch, voltmeter with selector switch, kWh
meter, wattmeter, frequency meter and power factor meter.
Surge arrester/suppressor, diode failure, loss of excitation, and over excitation shall be
provided for generator protection.
9.2
Switchgear/ MCC Incomer Feeders
The switchgear/ MCC incomer shall have the following protective and metering devices as a
minimum. The protection and metering device shall be multifunction electronic type
microprocessor based:

Thermal overload protection (49)

Overcurrent relay (50/51)

Earth fault (50N/51N)

Undervoltage relay (27)

Lockout relay (86)

Synchronising check relay (25)

Trip coil supervision relay (TCM)

Ammeter and voltmeter with selector switch
The switchgear bus-tie shall have synchronizing check relay (25).
9.3
Motor Starters
Motor starters shall comply with the Specification for HV Switchgear or Specification for LV
Switchgear and MCC, as applicable. All motor starter units shall each be equipped with a
intelligent motor protection relay (MPR) which is capable of providing a range of motorprotection functions, monitoring and metering functions, control functions through input/output
contacts, non-volatile memory (capable of storing data of up to 10 trip events), a LCD panel
as HMI- either as integrated into the MPR or one LCD panel shared with a group of MPRs,
and a serial interface for remote access/monitoring via an HMI.
All HV motors shall have RTD winding temperature detection provided.
LV motors which are controlled by variable speed drives (VFD) shall be appropriately be
provided with PTC thermistor or RTD winding temperature detection.
9.3.1
LV Motor
MCCB for protection against short circuit shall be provided in addition to either motor
protection relay or thermal overload relay.
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9.4
Transformer Feeder
Vacuum circuit breaker (VCB) unit with multifunction electronic type of protection relay shall
be provided.
Distribution transformers shall be connected in accordance with IEC standards, and shall be
controlled and protected on the primary side by the following:
VCB in conjunction with phase short circuit and earth fault protective relays shall be provided.
Phase short circuit protection shall be by means of two-stage overcurrent relays. Stage 1
shall be IDMT and set to detect secondary side faults. Stage 2 shall be instantaneous in
operation and set to detect primary side faults only. Primary side earth fault protection shall
be by a residual current relay, set to achieve minimum fault clearance time.
Unrestricted earth fault protection shall be provided on the (earthed) star connected windings
of distribution transformers. This shall be achieved by means of a relay that shall be
energised by a current transformer (CT) placed in the neutral-earth connection of the power
transformer secondary winding. The primary current rating of the CT supplying this relay shall
correspond to the nominal current of the transformer secondary or to the current as limited by
resistance earthing. The characteristic of this relay shall be extremely inverse. The setting of
the earth fault protection relay shall be the minimum practicable.
9.5
Feeders
a) Non-motor feeder MCCB rated at 400A and below may be equipped with built-in
electronic type thermal-magnetic type release.
b) Non-motor feeder MCCB rated above 400A and ACB shall be equipped with Feeder
Protection Relay (FPR) and shunt-trip release.
9.6
Small Power and Lighting
Distribution board main incomer shall be provided with thermal-magnetic MCCB for protection
against overload and short circuit.
All small power and lighting outgoing circuits shall be protected by miniature circuit breaker
(MCB) against overload and short circuit.
Each outgoing circuits for socket outlets/ receptacles shall be provided with earth leakge
circuit breakers.
10.0
EARTHING
10.1
System Earthing
System earthing arrangement for individual systems shall be as follow:
System Voltage
Earthing
6.0kV
Low resistance earthed at HV main power generator neutral
star point
400V
Solidly earthed at distribution transformer secondary star
point and LV emergency power generator neutral star point.
Instrument I.S.
Instrument I.S. earthing system
Instrument Non IS
Instrument clean earthing system
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The LV power generation and distribution neutral for BK-TNG, being “solidly ground” shall be
designated as ‘TN-S’.
Generator neutral resistor and transformer star point are connected directly to main platform
steel structure beam via dedicated connections. Electrical earthing grid, instrument IS earth
and instrument non IS earth are connected directly to main platform steel structure, minimum
at two point per earthing system. All other earthing points shall be connected to main platform
steel structure beam.
10.2
Equipment Earthing
All exposed metal of electrical items, equipment and installation other than current carrying
parts will be double bonded and earthed, that is earthed via a separate earthing conductor
connected from the equipment frame externally to the earthing grid.
All non-electrical metallic equipment and installation not welded to structural steel framework
including skid mounted packages, vessel, steel structures etc. will be provided with (two
diagonally opposite where possible) earthing bosses bolted to the equipment skid. Earthing
conductors will then be connected to the equipment earthing from main structure beam.
Earthing conductors are required to bond the main components of the generation and
distribution systems (namely HV and LV generators, transformers, switchboards, motors and
UPS units) to the platform steelwork/ main structure beam.
The computer/printer shall have earthing system separate from other power equipments.
Proper earthing to the transformer must be provided when welding of equipment to foundation,
base plates and piping. Earthing cables shall never be connected to any part of rotating
equipment including base plates, pedestal, drive, etc.
All cable racks / ladders / trays shall be earth bonded between sections and to welded steel
structures and in no event the intervals shall exceed 25m.
On cabinets or panels with hinged doors, earthing integrity shall be assured by the use of
flexible earth bonding straps between the fixed and moving parts of the cabinet/panel.
The cross-sectional area of branch conductors connecting equipment and structures to the
main earth ring shall be as follows:
10.3
To metallic enclosure of HV electrical equipment
:
70 mm²
To metallic enclosures of LV electrical equipment, having a supply
cable cross-sectional area > 35 mm²
:
70 mm²
To metallic enclosures of LV electrical equipment, having a supply
cable cross-sectional area < 35 mm²
:
70 mm²
To control panels. Etc.
:
25 mm²
To non-electrical equipment exposed to lightning, e.g. tanks,
columns and tall structures
:
70 mm²
To other non-electrical equipments
:
25 mm²
Lightning Protection
Offshore platform topside shall be of fully structural steel construction welded to the jacket
and the jacket bonded to the ground. Hence conventional lightning protection system for the
fixed offshore platforms not required.
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However, the communication tower located on the top deck shall have separate air
termination rod and down conductors that will be bonded to the platform structural steel.
Other tall structure such as flare tower, pedestal crane … on the platform shall be protected
against lightning by effecively earthing them to the nearest platform primary steelwork thus
providing a direct low impedance path for the lightning discharge to ground.
Lightning Surge Arresters shall be required for sensitive field instruments such as CCTV
cameras and antennas inside PCS marshalling cabinet for field bus loops. Lightning surge
arrestors shall be provided if recommended by the vendors for SIS/FGS cabinets, field
instruments, etc.
Furthermore, where the metal frame or steel structure is not welded to platform deck or
steelworks, and therefore is not continuous to earth, adequate bonding shall be provided.
Lightning protection on processing platform shall be in accordance with NFPA 780.
11.0
EQUIPMENT CLEARANCE
Recommended equipment clearance is as follows:
Item
Clearance
HV Switchgear (front)
1500 mm
LV Switchboard / MCC (front)
1200 mm
Distribution panel, large junction box (front)
1200 mm
Control panel, UPS
1200 mm
Switchgear & LV Switchboard / MCC (side)
800 mm
Transformer (all sides)
800 mm
Battery banks
900 mm
Personnel access
800 mm
Between cable ladder/tray (between bottom of ladder/tray)
- Horizontal parallel for outdoor installation
400 - 450 mm
- Horizontal parallel for indoor installation
350 - 400 mm
- Vertical parallel
300 mm
Batteries
- Shelves depth (not more than)
760 mm
- Batteries arranged in two or more tiers, each shelf space
back and front (minimum space)
- Above each cell (minimum space)
12.0
60
mm
300 mm
ELECTRICAL ROOM REQUIREMENT (WITH RAISED FLOOR)
Electrical Safety Warning signs shall be prominently displayed on the appropriate individual
sections of electrical equipment within the buildings. This shall include, but not limited to
voltage level warning signages.
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The main Switchgear/MCC room shall be furnished safety equipment cabinet and electric
shock treatment / first aid posters.
The cabinet shall be arranged so that each tool or device is held in its own compartment and
unobstructed from the door. The cabinet shall be heavy duty painted sheet steel with locking
handle, locks, and door(s).
A framed A1 size, presentation quality of the key one-line diagram shall be mounted in
Switchgear/MCC room.
Switchgear/MCC rooms shall be furnished with electrical safety insulating mats along the
entire length of the switchboard which can be rolled-up and temporarily put away when
necessary.
All battery room floors shall be impervious to battery acid. A water tap, eye-wash basin, sink
and drain shall be provided and installed by the main door, inside the battery room.
Service and drainage lines that carry both liquids and compressed air shall not be routed
inside the Switchgear/MCC rooms.
13.0
ELECTRIC HEATERS FOR PROCESS/UTILITY APPLICATIONS
The heater control panel and associated heater shall be designed to provide continuous
operation at rated output to suit process gas temperature conditions as per stipulated process
requirements.
Electric heater power shall be regulated by thyristors fired according to the zero crossover
mode (with a controlled output power range down to 1 cycle) in conjunction with stepcontroller; unless approved by Company, phase angle control shall not be utilised as a
solution for power regulation.
Electric heaters with total load greater than 45kW shall be split into smaller discrete heater
loads. These discrete heater loads should be controlled by step-controller acting on power
contactors, with one remaining as “thyristor controlled”.
Thyristor stack protection shall include over-current protection by means of ultra rapid fuses
and voltage transient suppressors.
The heater shall be located outdoors and be designed to withstand the environmental
conditions as specified in this document.
The heater elements shall be designed to withstand the highest possible temperature which
can occur under all process conditions.
Tubular heater elements shall be constructed from 80/20 NiCr (Nickel Chrome) resistance
wire surrounded by compacted magnesium oxide powder, designed to minimise peak in rush
current. The element shall include an overall sheath tube made from material providing
corrosion/ erosion resistance suitable for the operation.
10% spare (of the total number of elements required to fulfil the operational duties of the unit)
installed heater elements, but not connected, shall be provided. All spare elements shall be
fitted with wires of sufficient length to connect the element to any bus-bar in the event of their
use. The number of heating elements provided in the heater bundle shall be indicated.
Heater elements shall be protected against over-temperature by means of at least two
thermocouples. The devices shall be clamped or welded to the sheaths of elements (different
phases) and located in an area of highest anticipated sheath temperature.
Electrical Heater shall be provided with thermocouple control to cut-off the heater in case of
high skin temperature.
Temperature sensing wiring shall be brought out to separate terminal box of IP 66 rating.
Terminal boxes material shall be stainless steel SS 316L.
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Thermocouple material shall be chromel-alumel with swaged sheath mineral oxides. The
thermocouple sheath shall be of the same material as the heating element sheath with a
minimum wire size of 0.75mm2. Thermocouple wires extending from the sheath shall be
hermetically sealed in the head.
The design of the Heater Control Panel shall be provided with the facilities for remote and
monitoring operation with PSMCS and DCS.