Revision A
Page 2
CONTENTS
1.0
Introduction
2.0
Custodian
3.0
Purpose
4.0
Application
5.0
Scope of Supply
5.1
5.2
5.3
5.4
Power, control and earthing cables
Cable glands
Equipment not included in the scope of supply
Definition of non-technical terms
6.0
Service and Environmental Conditions
6.1
6.1.1
6.1.2
6.2
6.3
6.4
Ambient temperature for design purposes
Air temperature
Ground temperature
Thermal resistivity of the ground or soil
Rating of cables for site conditions
Short circuit current withstand capability
7.0
International Reference Standards
8.0
General Requirements
8.1
8.2
8.3
8.4
8.5
The Supplier’s product range
Origin of materials
Project management
Abbreviations of some technical terms used herein
Supplier’s drawings and documents
9.0
Design and Performance Requirements
9.1
9.2
9.3
9.4
9.5
9.6
9.7
9.7.1
9.7.2
9.7.3
9.7.4
9.8
9.8.1
9.8.2
9.8.3
9.9
9.10
Voltage and frequency variations
The electrical power system
Conductor maximum continuous operating temperature
Conductor maximum short-circuit operating temperature
Short-circuit K values for copper conductors
De-rating factors for cables laid in air
De-rating factors for cables laid in ground
Direct burial
Use of ducts
Pre-formed concrete trenches
The use of lead sheathing
Flame propagation, smoke production and toxic gas emission
Flame propagation
Smoke production and toxic gas emission
Oxygen index
Fire resistance
Resistance to hot oils
Revision A
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10.0
Construction Requirements
10.1
10.2
10.3
10.4
10.5
10.6
10.7
10.8
10.9
10.10
10.10.1
10.10.1.1
10.10.1.2
10.10.2
10.10.2.1
10.10.2.2
10.11
10.11.1
10.11.2
10.12
10.12.1
10.12.1.1
10.12.1.2
10.12.2
10.12.2.1
10.12.2.2
10.12.3
10.12.4
10.13
10.13.1
10.13.2
10.13.3
10.14
10.14.1
Notation used in this document
Conductors
Conductor screening
Conductor insulation
Insulation screening
Insulation screening tape
Bedding between multi-cores
Inner sheathing
Armour
General requirements
Land-based installations
Normal use in the air or in the ground
Abnormal use in the air or in the ground
Platform-based installations
Normal use in the air
LV cables in accommodation areas
Outer sheathing
Power distribution cables
Earthing cables
Other components
Fire survival in non-accommodation areas
HV cables
LV cables
Fire survival in accommodation areas
HV cables
LV cables
Earthing cables
Special applications
Colours of components
Conductors
Outer sheathing colour
Outer sheathing marking
Cable glands
Cable dimensional tolerances
11.0
Inspection
12.0
Testing
12.1
12.2
General
Type tests, sample tests and routine tests
13.0
Packing
13.1
13.2
General
Drum marking
14.0
Approval to Deviate
15.0
Revision History Log
16.0
Bibliography
Revision A
Page 4
1.0
Introduction
This is an engineering standard that gives details of power, control and earth cables and
associated glands for high voltage and low voltage systems.
Note that any changes to this document from its last revision are highlighted by a
bold vertical bar to the left of each area of change. Should there be a need to consult
this document’s change history log, refer in the first instance to its custodian (EE).
References made throughout this guideline are numbered inside square brackets [ ] and
may be found in the Bibliography of section (16).
2.0
Custodian
The Custodian of this standard guideline is EE, who is responsible for the accuracy and
quality of its contents and for its future revisions, where these are required to reflect
industry trends or changes to QGPC business practices.
3.0
Purpose
The purpose of this standard is to provide guidance to QGPC, their Consultants and
Contractors on the cables and accessories utilised by QGPC for voltages up to 33000
Volts. This specification is based on QGPC Engineering Design Philosophy ES.2.03.0001
and QGPC Electrical Installation Practices ES.2.06.0001.
4.0
Application
This standard shall be applied to the design, manufacture and testing of 33kV, 11kV,
6.6kV, 3.3kV, and low voltage power, control and earthing cables to be installed for
various projects of Qatar General Petroleum Corporation (QGPC).
5.0
Scope of Supply
5.1
Power, control and earthing cables
This specification details the requirements for industrial type, power distribution cables,
control cables of the single and multi-core type and single core earthing cables.
The cables will normally be installed indoors, outdoors, in air and in the ground at QGPC
oil and gas processing plants, refineries, chemical plants, LNG plants, off-shore platforms,
industrial sites, and the like. This specification shall be used to purchase equipment for
both existing and new plants.
As a rule the requirements of this specification shall be adhered to. However, national and
local regulations may exist in which some of their requirements are more stringent.
The Supplier shall inform the Principal in writing of any deviation from the technical
requirements of this specification, preferably at the tendering stage, but certainly before the
manufacturing commences. Otherwise the Principal will consider that the Supplier
complies with these technical requirements and will be manufacturing the cable
accordingly.
Revision A
Page 5
This specification covers the design, manufacture and testing of 33 kV, 11 kV, 6.6 kV, 3.3
kV and low voltage power, control and earthing cables for various projects of Qatar
General Petroleum Corporation (QGPC) in Qatar, Arabian Gulf
The requirements for drawings and documentation are given in section 8.5.
5.2
Cable Glands
Industrial type cable glands are recommended for terminating cables of single and multicore type for all QGPC operations. Zone 2 classified areas may require the use of barrier
type glands. The Principal shall specify these on the data sheets. Reference should also be
made to Engineering Philosophy ES.2.03.0001 Appendix H table H3.A and Installation
Specification ES.2.06.0001 Section 16.4.
5.3
Equipment not included in the Scope of Supply
The following equipment shall be excluded from the scope of supply of cables and glands
of the SUPPLIER unless specified in other documents of the requisition.
• Submarine cables.
• Cable jointing equipment and splices.
• Heat-shrink termination kits and equipment.
• Terminating lugs and tools and test equipment.
• Racking and trays.
• Underground cables at a voltage higher than 33 kV.
5.4
Definition of Non-Technical Terms
For the purposes of this document the following definitions of terms and interpretations
shall apply regardless of any other meaning the words may have in other respects.
Shall.
The word shall is to be understood as mandatory.
Should.
The word should is to be understood as being strongly recommended.
Principal.
Is the party, which initiates the project and ultimately pays for its
design and construction. The Principal will generally specify the
technical requirements. The Principal may also include an agent or
consultant to act for the Principal.
Contractor(s).
Is the party, which carries out all aspects or part of the design,
engineering, procurement, construction and commissioning of the plant.
The Principal may sometimes undertake all or part of the duties of the
Contractor.
Manufacturer
or Supplier.
Is the party which manufactures or supplies
equipment and services to perform the duties specified.
End-user.
A third party that has already purchased the same equipment as that
being offered by the manufacturer, or supplier.
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6.0
Inspection.
This shall be taken to mean a visual inspection of the equipment and
installation.
Testing.
This shall be taken to mean the routine tests normally carried out at the
factory of the Supplier.
Commissioning.
This shall be taken to mean energisation and the final tests and checks
at the Principal’s site subsequent to the energisation necessary to
ensure that each circuit satisfactorily performs its function.
Land-based
installations
All plants installed on the mainland of Qatar. All plants installed on
Halul Island. Abbreviated to LBIs.
Platform-based
installations
All plants installed on elevated platforms or moored installations
vessels located in the sea or waters around Qatar. Abbreviated to PBIs.
Service and Environmental Conditions
The atmosphere and ground throughout all QGPC plants shall be considered to be
corrosive, as normally associated with oil and gas processing plants, refineries, chemical
plants, LNG plants, off-shore platforms, industrial sites, and the like. In addition, for
offshore and coastal locations, the atmosphere shall be considered as salt laden and the
ground as having a corrosive water table near its surface.
High humidity is experienced in all areas and condensation will occur on all equipment
during some period of its lifetime.
6.1
Ambient Temperature for Design Purposes
6.1.1
Air Temperature
The ambient air temperature shall be considered as a maximum of 50 °C. The Supplier
shall take this into account in the design and selection of materials for his cables, and when
calculating and quoting de-rating factors for normal rated currents and fault currents of the
cables.
The Supplier shall quote his nominal temperature for which his de-rating factor for
ambient temperature is 1.0 in his tender documentation.
6.1.2
Ground Temperature
The ambient ground temperature shall be considered as a maximum of 40°C.
6.2
Thermal Resistivity of the Ground or Soil
The thermal resistivity of the ground or soil shall be taken as 2.5 K m/W for general
guidance. Soil tests should be taken at all sites to identify areas where the thermal
resistivity is likely to be higher than 2.5 K m/W e.g. well-drained sand where heavily loaded
cables are to be buried and operated continuously in the summer.
6.3
Rating of the Cables for Site Conditions
Revision A
Page 7
The cable manufacturer shall not be responsible for sizing the cables for normal current
conditions for a particular project.
6.4
Short Circuit Current Withstand Capability
The Supplier shall provide detailed information in his tender documents for the Isquared-t short circuit current withstand capability which is applicable over the time
range of 0.2 to 10.0 seconds. This information shall be given in the form of equations or
graphs for: -
7.0
a)
The conductors.
b)
The armouring wires or braid.
International Reference Standards
The following standards and specifications shall be used unless the Principal approves
another national standard: (Add to all references e.g. IEC 34 becomes IEC )60034
Standard Compliance
IEC 43
Recommendations for alternating current watt-hour meters.
IEC 92-3
Electrical installations in ships.
Part 3: Cables (construction, testing and installation) wires or cables.
IEC 183
Guide to the selection of High Voltage Cables
IEC 189
Copper conductors.
IEC 331
Fire resisting characteristics of electric cables.
IEC 332
Tests on electric cables under fire conditions.
IEC 502-1
Extruded solid dielectric insulated power cables for rated voltages from
1 kV up to 30 kV.
IEC 540
Test methods for insulations and sheaths for electric cables and cords
(elastomeric and thermoplastic compounds).
IEC 754
Tests on gases evolved during combustion of electric cables.
IEC 885
Electrical test methods for electric cables.
BS 2621
Mechanical cable glands.
BS 2782
Methods of testing plastics.
BS 5467
Armoured cables with thermosetting insulation for electricity supply.
BS 5468
BS 6004
Cross-linked polyethylene insulation systems of electric cables.
PVC insulated cables (non-armoured) for electric power and lighting.
Revision A
Page 8
BS 6346
PVC cables for electricity supply as relevant to the contract cables with
XLPE insulation.
BS 6360
Copper conductors in insulated cables and cords.
BS 6425
Test on gases evolved during the combustion of materials from cables.
BS 6746
Specification for PVC insulation and sheath of electric cables
BS 7211
Non armoured cables for power and lighting with low emission of
smoke/gases
8.0
General Requirements
8.1
The Supplier’s Product Range
It is a general requirement that the supplier offers only cable that is within his standard
range of cables. Any cable that is ‘bought-in’ from a third party shall also be from a
standard range of products from the third party, but subject to the approval of the
Principal. The cable shall not be a new product-line that has not been sold in reasonable
quantities to similar end-users as QGPC. The Supplier shall include in his quotation a list
of end-users in the Middle East region that have purchased the same cable being offered.
8.2
Origin of Materials
The Supplier shall offer all the cables in the purchase order from his own factory in one
country; preferably the country where the purchases order will be managed by the
Supplier. Type Test certificates shall be in the name of the Supplier for the cable, and not
in the name of a third party manufacturer or vendor. The Supplier shall confirm this
paragraph in his quotation.
8.3
Project Management
The Supplier shall nominate a single person to manage the project and this person shall be
the single ‘focal point’ for all discussions, meetings, communications, correspondence, and
the like, between the Supplier and the Principal.
8.4
Abbreviations of Some Technical Terms Used Herein
The definitions for some technical words and abbreviations used in this specification and
the QGPC M.E.S.C. system are: DATA SHEETS
This includes all relevant data sheets, diagrams and drawings issued
with the enquiry or purchase order package.
AWA
Aluminium wire armour
CSP
Chloro-sulphonated polyethylene
COR CU
Corrugated copper
CU
Un-tinned copper
CUWB
Copper wire braid
Revision A
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EMA
Ethylene methyl acrylate
EPDM
Ethylene propylene diene monomer
EPR
Ethylene propylene rubber
EVA
Ethylene vinyl acetate
FLEX
Flexible
GSWA
Galvanised steel wire armour
GSWB
Galvanised steel wire braid
HCL
Hydrochloric acid or gas
HOFR
Heat and oil resisting, flame retardant
IS
Intrinsically safe
LDF
Low density foam
LSLH
Low smoke low halogen
MI
Mineral insulated
MT
Mica glass tape
NBR
Nitrile butadiene rubber
PBWB
Phosphor bronze wire braid
Pb
Lead sheathing
PbCU or TCU
Tinned copper
POL
Polyethylene
PTP
Polyethylene terephthalate
PTFE
Polytetra fluoro ethylene
PVC
Polyvinyl chloride
PVDF
Polyvinyldiene fluoride
SCR
Screened
SOL CU
Solid copper
STR CU
Stranded copper
SWA
Steel wire armour
XLPA
Cross linked polyalkylene
XLPE
Cross linked polyethylene
M.E.S.C
Material and Equipment Stores Catalogue (Shell)
IEC
International Electrotechnical Commission.
BSI
British Standards Institution.
S.I.
System International.
RMS
Root mean square value of current or voltage.
Pk
Peak value of instantaneous current or voltage.
A.C. or a.c.
Alternating current or voltage.
D.C. or d.c.
Direct current or voltage.
Revision A
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8.5
Hz
Frequency of alternating current or voltage in cycles per second.
FAT
Factory acceptance testing.
HV
High voltage, above 600 volts.
LV
Low voltage, 51 volts to 599 volts.
°C
Degrees Celsius
SCADA
System control and data acquisition.
DCS
Distributed control system
Supplier’s Drawings and Documents
All drawings and documents shall be expressed in the English language and units of
measure shall be generally in accordance with the S.I. system.
The Supplier shall submit with his tender documents cross-sectional area drawings to
illustrate the proposed construction of all the types of cables being offered. These
drawings shall also indicate the dimensions and diameters of the main components e.g.: *
*
*
*
*
*
*
*
Outside diameter of the outer sheathing.
Inside diameter of the outer sheathing.
Outside diameter of the armouring.
Inside diameter of the armouring.
Outside diameter of the inner sheathing.
Inside diameter of the inner sheathing.
Outside diameter of the conductor insulation including the semi-conductor screening if
provided.
Outside diameter of each conductor.
The dimensions, and their tolerances, may be shown in tabular form instead of in the
drawings.
9.0
Design and Performance Requirements
9.1
Voltage and Frequency Variations
The cables shall operate correctly, continuously and without being overloaded when the
Principal’s nominal system voltages deviate by plus or minus 10 % for long periods of
time. Likewise when Principal’s nominal system frequency deviates by plus or minus 5%.
The worst cases of simultaneous variation of voltage and frequency shall be withstood by
the cables.
9.2
The Electrical Power System
The Principal shall state the rated power system voltage and frequency on the data sheets.
9.3
Conductor Maximum Continuous Operating Temperature
The conductor maximum continuous operating temperature shall be no greater than that
given by the Supplier of the cables when the current has been reduced by the appropriate
de-rating factors for the project, see 9.6, 9.7. The Supplier shall clearly state the value of
the conductor maximum continuous operating temperature in his tender
Revision A
Page 11
documentation. This temperature should not exceed the value given below for typical
designs of power cables: Insulation material
Maximum continuous
conductor temperature
°C
Paper
PVC
EPR
XLPE
9.4
65
70
90
90
Conductor Maximum Short-Circuit Operating Temperature
The conductor maximum short-circuit operating temperature shall be no greater than that
given by the Supplier of the cables. The Supplier shall clearly state the value of the
conductor maximum continuous operating temperature in his tender documentation.
This temperature should not exceed the value given below for typical designs of power
cables: Insulation material
Paper (compression connections)
Paper (lead solder connections)
PVC < 300 mm2
PVC > 300 mm2
PVC > 6600 V
EPR
XLPE
9.5
Maximum short-circuit
conductor temperature
°C
250
160
160
140
140
250
250
Short Circuit K Values for Copper Conductors
The short circuit K values for use in I-squared-t calculations, for copper conductors
surrounded by different insulation materials, armouring and sheathing, shall be taken as
guidance to be: Insulation material
Paper (compression connections)
Paper (lead solder connections)
PVC < 300 mm2
PVC > 300 mm2
PVC > 6600 V
EPR
XLPE
Short-circuit K value
A-secs0.5/mm2
250
160
150
130
130
250
250
The time duration of the full fault current shall normally be no less than one second, unless
the cable is protected by fast acting fuses in which case the fusing time shall be taken into
account.
9.6
De-rating Factors for Cables laid in Air
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The cables may be laid on racks, trays or ladders in the vertical or horizontal plane and
with various bunching arrangements. The Supplier shall provide de-rating factors for his
cables for these laying situations, preferably in the form of numerical tables.
9.7
De-rating Factors for Cables laid in Ground
9.7.1
Direct Burial
The cables may be laid directly in the ground at various depths and with various bunching
arrangements. The Supplier shall provide de-rating factors for his cables for these laying
situations, preferably in the form of numerical tables.
9.7.2
Use of Ducts
The cables may be laid inside ducts in the ground at various depths and with various
bunching arrangements. This is normally needed for road crossings. The Supplier shall
provide de-rating factors for his cables for these laying situations, preferably in the form of
numerical tables.
9.7.3
Pre-Formed Concrete Trenches
The cables may be laid in pre-formed concrete trenches in the ground at various depths and
with various bunching arrangements. These trenches will be filled with still air and may be
provided with racking and supports, and concrete lids will be used to close the trench. The
Supplier shall provide de-rating factors for his cables for these laying situations, preferably
in the form of numerical tables.
9.7.4
The Use of Lead Sheathing
For special situations e.g. tank farms, chemical plants, the Principal shall specify a lead
outer sheathing for the cable to protect the cable from chemical attack. The effect of the
lead sheathing should be taken into account in the de-rating factors for buried cables.
9.8
Flame Propagation, Smoke Production and Toxic Gas Emission
9.8.1
Flame Propagation
All cables shall be constructed with materials that are of the Reduced Propagation of Fire
type. The method of test and test configuration used to demonstrate the capability should
be as defined by IEC 332 “Tests on electric cables under fire conditions”.
9.8.2
Smoke Production and Toxic Gas Emission
The cable materials shall be chosen such that the hazard of smoke and toxic gas emission
(e.g. Hydrochloric acid gas, halogens) during a fire shall be minimised. The data to be used
shall be taken from IEC 332-2.
9.8.3
Oxygen Index
Revision A
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The oxygen index of all non-metallic materials except the insulation shall be not less than
30 as described in BS 2782 or IEC 754.
9.9
Fire Resistance
Specified cable circuits and routes will utilise cables that shall have a continued electrical
performance under fire conditions, e.g. emergency shutdown systems and their power
supplies. The method of test to be used to demonstrate this capability should be as defined
by IEC 331-1. This will be achieved by means of glass mica tape applied over the
conductors in the form of a helix.
Mineral Insulated Copper Cables (MICC) are prohibited for use for vital services.
9.10
Resistance to Hot Oils
Cables that are required to operate where there is oil present shall be certified for oil
immersion test recommended by the Supplier
10.0
Construction Requirements
10.1
Notation Used in This Document
The generally accepted construction of the cable components is defined in this document as
follows in a LHS to RHS format: *
Conductor / insulation / armouring / outer sheathing
An example of which is: -
CU / XLPE / SWB / CSP
There will be other components for particular applications e.g. system voltages above 3300
volts where semi-conducting screening may be needed for electric stress relieving.
10.2
Conductors
The conductors shall be made of high purity electrolytic copper in accordance with BS
6360. The Principal shall specify that the conductors shall be tin-coated where this is
necessary for special situations. Aluminium shall not be used.
The Principal shall specify that the conductors shall be finely stranded where this is
necessary for special situations.
The conductors shall be circular in section, stranded, annealed copper conductors. Sector
shaped conductors shall not be used.
The conductors of multicore cables shall be laid up with solidly extruded non-fibrous, nonhygroscopic fillers to form a compact circular cable.
10.3
Conductor Screening
The conductors for cables in which the phase-to-ground operating voltage is greater than
3600 volts RMS for PVC or XLPE insulation or 6000 volts RMS for EPR insulation shall
be provided with a semi-conductor screen, which shall be bonded to the inner surface of the
insulation.
Revision A
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The Supplier shall confirm the need for this screening and describe how it is bonded to the
insulation.
10.4
Conductor Insulation
The insulation material shall be extruded over the conductor and be PVC, XLPE or EPR
as stated in the data sheets for the project. EPR shall only be used for operating line-to-line
voltages up to 6600 volts RMS.
Insulation grades for various service voltages shall be as follows: -
System Voltage
(U)
33kV system
11kV system
6.6kV system
3.3kV system
440V system
415V/240V system
380V/220V system
10.5
Rated Voltage/Nominal System Volts
(U0/U)
18kV/30kV
6kV/10kV
3.6kV/6kV
1.8kV/3kV
600V/1000V
600V/1000V
600V/1000V
Highest Voltage
(Um)
36kV
12kV
7.2kV
3.6kV
Insulation Screening
The insulation of conductors for cables in which the phase-to-ground operating voltage is
greater than 3600 volts RMS for PVC or XLPE insulation or 6000 volts RMS for EPR
insulation shall be provided with a semi-conductor screen, which shall be bonded to the
outer surface of the insulation.
The Supplier shall confirm the need for this screening, and describe how it is bonded to the
insulation and how it should be removed during the termination of the cable e.g. stripping.
10.6
Insulation Screening Tape
A copper tape wound in an over-lapped helical manner shall cover the insulation screening.
Aluminium shall not be used.
The Principal shall specify that the copper tape shall be tin coated where this is necessary
for special situations.
10.7
Bedding Between Multi-Cores
Bedding shall be included in the design of the cable to ensure that the cable is robust and
firm, and that passages are not present that could allow gases to be transmitted along the
cable. The bedding shall also ensure that the overall diameter of the finished cable is
constant (subject to the tolerances given in the appropriate IEC standard) throughout the
periphery of the cable.
Good “roundness” is an essential requirement.
10.8
Inner Sheathing
Revision A
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An inner sheath shall be provided over the bedding and insulation. For HV cables it shall
be resistant to ozone, electric discharge and surface tracking.
The inner sheath and fillers shall provide a good longitudinal seal against humidity, gas
and vapours.
10.9
Armour
Armouring shall be provided except for special applications.
The Principal shall clearly state on the data sheets whether armouring is not required.
The Principal shall clearly state on the data sheets type of armouring that is required, e.g.
wires in single or double layers, braid, galvanised steel, tinned copper, aluminium, bronze,
stainless steel. See 10.9.1 and 2.
Aluminium, tinned copper or bronze wires or braid shall be used for single cables, as
stated on the data sheets.
The armouring shall be highly conductive for fault currents and the addition of some
copper wires or strands in the armouring may be necessary to reduce the armouring
impedance for long lengths of cables in sensitive situations. The Principal should call for
this requirement if it is needed in the project documentation.
a) Armour shall provide mechanical protection (except those specified in the data sheet).
The armour shall be of single galvanised steel wire.
b) Galvanised steel wire braid shall be used for flexible cables and cables up to and
including 10 mm2.
c) The thickness of steel wire shall comply with IEC 502.
d) Particular consideration shall be given to the problem of armour becoming embedded
in the inner sheath making separation for termination difficult.
e) A stick-proofed tape shall be provided between the inner sheath and the braid.
10.10
General Requirements
Cables shall have Oxygen Index greater than 30 and acidic emission less than 17%.
Maximum cross–sectional area for multicore cable shall be limited to 240 mm2.
Cables for offshore installations shall be low smoke low halogen types (LSLH).
Cables to be used on HV circuits shall be cross-linked polyethylene (XLPE) insulated,
steel wire armoured, UV stabilised, PVC oversheath, construction having flame retardant
design in accordance with IEC 332 – 3 Cat. A.
LV cables for use on vital circuits shall be of fire resistant design in accordance with IEC
331. Cables meeting this requirement will be of cross-linked polyethylene (XLPE)
insulated, steel wire armoured or braided, UV stabilised, PVC oversheath construction.
10.10.1
Land-Based Installations
Revision A
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10.10.1.1
Normal use in the air or in the ground
The cable construction shall be: For multi-cores cables
CU / XLPE / GSWA / PVC
or
CU / XLPE / GSWA / XLPE
For single-core cables
CU / XLPE / PBWB / PVC
or
CU / XLPE / PBWB / XLPE
For single-core cables in air (not in ground)
CU / XLPE / AWA / PVC
or
CU / XLPE / AWA / XLPE
10.10.1.2
Abnormal use in the air or in the ground
In abnormal situations (e.g. where oil spillage is expected) the cable construction shall
incorporate a lead sheath: For multi-cores cables
CU / XLPE / PVC / Pb/ PVC or CU / XLPE / XLPE / Pb / XLPE
For single-core cables
CU / XLPE / PVC / Pb / PVC or CU / XLPE / XLPE / Pb / XLPE
Due considerations shall be given while using Lead Sheathed Cables. These cables shall be
used only for those locations where spillage of oil/hydrocarbons/chemicals is expected.
10.10.2
Platform-Based Installations
10.10.2.1
Normal use in the air
LV cables shall be cross-linked polyethylene (XLPE) insulated, galvanised steel wire
armoured (or braided for < 10 mm2.), UV stabilized, PVC oversheath construction having
flame retardant design in accordance with IEC 332-3 Cat A. Ethylene Propylene Rubber
(EPR) with Chloro-sulphonated Polyethylene (CSP) oversheath is also acceptable.
The cable construction shall be: For multi-cores cables where flexibility or oil resistance is required
CU / XLPE / CSP / GSWB / CSP or CU / EPR / CSP / GSWB / CSP
For multi-cores cables in general use
CU / XLPE / PVC / GSWA / PVC or CU / EPR / PVC / GSWA / PVC
For single-core cables where flexibility or oil resistance is required
CU / XLPE / CSP / PBWB / CSP or CU / EPR / CSP / PBWB / CSP
For single-core cables in general use
CU / XLPE / PVC / AWA / PVC or CU / EPR / PVC / AWA / PVC
10.10.2.2
LV Cables in Accommodation Areas
Revision A
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The EPR insulation shall be covered with an inner sheath of EMA or an acceptable
alternative material.
The armouring shall be covered with an outer sheath of EMA or an acceptable alternative
material.
The cable construction shall be: For multi-cores cables
CU / EPR / EMA / GSWB / EMA
For single-core cables
CU / EPR / EMA / PBWB / EMA
10.11
Outer Sheathing
10.11.1
Power Distribution Cables
An outer sheath shall be extruded over the armouring, and lead sheathing if used. The
oversheath shall be PVC with the necessary additives to obtain the following
characteristics: a) Flame retardant (IEC 332-3 Category A)
b) Minimum production of noxious gases and fumes in the event of fire (less than 17%
release of acidic emissions).
c) Proof against aliphatic hydrocarbons
10.11.2
Earthing Cables
Earthing cables shall be insulated as described in 10.12.3 and the insulation material shall
be coloured green and yellow.
10.12
Other Components
The Supplier shall describe in his tender documentation any other components that
form part of the cable design, and their purpose, for example mica tape for fire
resistance.
10.12.1
Fire Survival in Non-Accommodation Areas
10.12.1.1
HV Cables
HV cables should be considered to have sufficient material in their insulation to withstand
fire conditions for the short period of time during which the HV system will shut down and
the emergency systems start-up and supply the essential and vital services.
10.12.1.2
LV Cables
The conductors shall be wrapped with mica tape.
Revision A
Page 18
The insulation shall be covered with an inner sheath of EPDM or an acceptable alternative
material.
The cable construction shall be: For multi-cores cables where fire resistance is required
CU / MT / XLPE / EPDM / GSWB / CSP
or
CU / MT / EPR / EPDM / GSWB / CSP
For single-core cables where fire resistance is required
CU / MT / XLPE / EPDM / PBWB / CSP
or
CU / MT / EPR / EPDM / PBWB / CSP
10.12.2
Fire Survival in Accommodation Areas
10.12.2.1
HV Cables
As for 10.12.1.1
10.12.1.2
LV Cables
The conductors shall be wrapped with mica tape.
The insulation shall be covered with an inner sheath of EMA or an acceptable alternative
material.
The armouring shall be covered with an outer sheath of EMA or an acceptable alternative
material.
The cable construction shall be: For multi-cores cables where fire resistance is required
CU / MT / EPR / EMA / GSWB / EMA
For single-core cables where fire resistance is required
CU / MT / EPR / EMA / PBWB / EMA
10.12.3
Earthing Cables
For cables used for earthing and bonding structures, frames, vessels etc., Their
construction shall be: For general use
CU / PVC
For increased flexibility and resistance to oil is required
CU / EPR / CSP
10.12.4
Special Applications
The Principal should be consulted for special applications, e.g. drilling rigs, down hole
pumps, drag chains, where the working conditions require flexible conductors, oil and mud
Revision A
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resistance, chemical contamination, extra protection against mechanical damage, prolonged
exposure to high temperatures, extra large conductor sizes, submarine cables, cables with
voltages in excess of 100 kV where special cross-bonding of armouring is necessary, etc.
10.13
Colours of Components
10.13.1
Conductors
Number of
phase and
neutral cores
Colour
Numbering
1
Black (or natural)
Not applicable
2
Red, Black
1 and 2
3
Red, Yellow, Blue
1, 2 and 3
4
Red, Yellow, Blue, Black
1, 2, 3 and 4
White with black numbers
1, 2, 3, 4, 5, etc.
more than 4
10.13.2
Outer Sheathing Colour
Service voltage
Volts
33000
Red
11000
Red
6600
Red
3300
Red
600/1000
Power control
cables
10.13.3
Colour
Black
Grey preferred, black acceptable
Outer Sheathing Marking
The manufacture’s name and voltage grade shall be permanently marked or embossed on
the surface of the outer sheathing at intervals of approximately 3 metres along the total
length of the cable. For the earthing cables in 10.12.3 this requirement is unnecessary.
10.14
Cable Glands
Cable glands shall be manufactured and tested to the requirements of BS6121 as EExd,
EExe and Industrial glands shall be nickel plated brass.
Revision A
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Entry threads shall be metric x 1.5mm pitch as standard.
The length of entry thread into EExd II flameproof equipment, which must be threaded,
shall be as detailed in BS EN 50018.
Cadmium plated brass glands are not acceptable throughout QGPC.
10.14.1
Cable Dimensional Tolerances
Cable gland selection shall be done in accordance with cable dimensions supplied by the
cable manufacturer. The corresponding gland sizes are selected from the Gland
manufacturer selection charts. Glands are manufactured to cover a range of cable sizes.
The gland selected should be based on the following procedure: a) Determine the requirements, i.e. EExd, EExe, or Industrial
b) Choose appropriate gland type, i.e. indoor, outdoor, armoured or unarmoured.
c) Check armour size and type.
d) Select gland size using inner sheath diameter of cable.
e) Check outer seal will accept cable outside diameter
f) Check entry thread size.
11.0
Inspection
The Principal or his nominated representative shall inspect cables.
The Supplier shall allow the Inspector all reasonable access to his factory and
documentation at any times during manufacture of the cables. The Inspector shall give no
less than 10 days notice for pre-planned inspection visits. The scope of Inspection shall be
agreed in advance between the Principal and the Supplier.
Approval of the Inspector shall not relieve the Supplier of his responsibilities under the
terms of the purchase and this specification and its accompanying documents.
12.0
Testing
12.1
General
The manufacturer shall have a QA/QC system based on ISO 9000 – 9004 controlling the
quality of design and assembly work during all stages of the production process.
A test program shall be established to demonstrate that each cable types will perform
satisfactorily in service.
Testing shall be performed in accordance with written test procedures prepared by the
Supplier and reviewed by the Principal. These procedures shall include provisions for
assuring that the pre-requisites for a given test have been met and that the test is performed
under suitable environmental conditions by appropriately trained personnel using recently
calibrated instrumentation.
12.2
Type Tests, Sample Tests, Routine Tests
The material supplied shall be subject to full works tests in accordance with the relevant
sections of the Standards as applicable to the material supplied
Revision A
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The following tests shall be effected: 12.2.1
Type Tests
Tests which are required to be carried out by the manufacturer to prove compliance with
the quoted specifications and standards.
Witnessing of these tests is not normally required, but certification of proof is to be
provided for the tests, which are as follows: -
12.2.1.1
Oil Immersion Test
Utilising “Cleanspot” and the existing Sterling Test Rig, in addition to a normal
immersion test.
12.2.1.2
Ageing Test
12.2.1.3
Water absorption
12.2.1.4
Tinning Tests on Conductors
12.2.1.5
Galvanising Tests on Armouring
12.2.1.6
Material Tests – Insulation and Sheath
12.2.1.7
Ozone Resistance
12.2.1.8
Resistance to Abrasion
12.2.1.9
Stripping Test
12.2.1.10
Bend Test
12.2.1.11
Full witnessed tests to IEC 502 for the High Voltage 33kV /6.6kV/3.3kV screened cables
12.2.2
Sample Tests
12.2.2.1
12.2.2.2
12.2.2.3
Reduced Propagation to IEC 332 Part 3, Category ‘A’.
Fire withstand test to IEC 331.
Smoke Emission to Appendix 1 of Sterling Report No. 117, which is based on the IEC
332 Part 2.
12.2.2.4
Oxygen Index.
12.2.2.5
Temperature Index.
12.2.3
Routine Tests
Tests to be carried out at regular intervals on each cable. Tests and records will be
witnessed during inspection visits.
Revision A
Page 22
12.2.3.1
Visual Examination
12.2.3.2
Marking
12.2.3.3
Dimensions
12.2.3.4
Conductor Resistance
12.2.3.5
HV Test
12.2.3.6
Partial Discharge
12.2.3.7
Insulation Resistance
12.2.3.8
‘IS’ Cable Tests (including check of capacitance, inductance, and L/R ratio)
12.2.3.9
Bending Test
13.0
Packing
13.1
General
The Supplier shall deliver the cables on wooden drums. Each wooden drum shall be in very
good condition before the cable is wound onto it.
The drum shall fully protect the cable, both radially and peripherally. Only one cable shall
be wound on a drum. The smallest drum shall be used to contain the cable. The drum shall
be returnable to the Supplier after the Principal has finished using it. The Supplier shall
make all the necessary arrangements for the removal of drums from the QGPC site.
The drum shall be protected to give adequate protection during shipment to the QGPC site,
in accordance with the particular requirements of QGPC the details of which will be found
in the purchase order documentation.
13.2
Drum Markings
The Supplier shall mark the drums with at least one indelible label. The label shall be
secured inside a waterproof but transparent plastic pocket. The pocket shall be nailed or
screwed to the face of the drum at a place where it can be easily seen. The language to be
used on the label shall be English. At least the following information shall be printed on the
label: *
*
*
*
*
*
*
*
*
*
*
Manufacturer’s name, address, telephone number, fax number, and telex number.
Manufacturer’s purchase order number and details.
Manufacturer’s cable type details.
QGPC’s purchase order number and details.
QGPC’s M.E.S.C reference number.
Date of manufacture.
Voltage grade.
Cable cross-section construction abbreviations, see 10.1.
Total length of the cable.
Total weight of the cable.
Unique drum number.
Revision A
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14.0
Approval to Deviate
Strict compliance with this standard guideline is required. Any deviation must obtain prior
written approval from its custodian.
15.0
Revision History Log
A record or log shall be kept of the revision history of each engineering document, and be
incorporated in the document’s accompanying electronic “readme” file [5]. In this way,
there should be no need for a history log to be included in a document - only details of its
latest approved revision need be shown (note that the readme file will contain information
about the particular operating system + application software versions which were used to
create the document’s electronic file; it can also include “help pages” in the form of
background notes and explanations, where such details are considered of benefit to its
reader).
The following is recommended for the contents of a document’s revision history log:Revision Number
Prepared By/Date
Checked By/Date
Approved By/Date
Reason For Change
Release/Date
16.0
0,1,2,3, etc.
Name or reference indicator and date (ddmmmyy)
Name or reference indicator and date (ddmmmyy)
Name or reference indicator and date (ddmmmyy)
Short description, with “change request reference” if available
Release/transmittal reference and date (ddmmmyy)
Bibliography
[1] ISO216: 1989, 1st Edition
[2]
[3]
[4]
[5]
ES.0.10.0001, Rev 0
ES.0.10.0002, Rev 0
ES.0.07.0010, Rev 0
ES.0.06.0021, Rev 0
Writing Paper and Certain Classes of Printed Matter Trimmed Sizes - A and B Series
Standard Database - Key Words & Phrases
Standard Database - Acronyms
Engineering Document Classifications
Electronic “ReadMe” Files
At the time of publication of this standard the revision of each of the above references,
as they cross-relate to the revision of this document, were valid. As all references are
subject to change from time to time, the reader is required to first check with the
custodian of this document to find out the latest “cross-revision” status with respect to
the above bibliographic list.