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BS 7917 Offshore Fire-Resistant Cables600/1000 VBS 7917 / IEC 60331Mica + GP4 EPR + SW4

BS 7917 U FR Unarmoured Fire-Resistant Offshore Power Cable0.6/1 kV (600/1000 V) unarmoured fire-resistant offshore power & control cable (Mica/EPR/S

Q: When is unarmoured BS 7917 U FR chosen over wire-braid armoured BS 7917 A FR?

BS 7917 U FR is specified inside enclosed offshore accommodation modules, switchgear rooms and protected internal cable trays where external mechanical impact risk is controlled and topside weight reduction is a priority.

Q: Why are tinned copper conductors mandatory in BS 7917 offshore cables?

Offshore platforms and FPSOs operate in salt-laden humid atmospheres containing hydrogen sulphide (H2S). Tin plating prevents copper sulphide corrosion on individual strands and ensures low-resistance crimp terminations over a 25-year offshore design life.

Q: What is the difference between SW4 and SW2 outer sheath compounds in BS 7917?

Both SW4 and SW2 are cross-linked halogen-free elastomeric compounds to BS 7655-2.6. SW4 provides standard oil resistance and low smoke emission, whereas SW2 offers enhanced tear strength, reduced flame propagation and superior swelling resistance against ester-based drilling muds.

Q: What is the difference between BS 7917 and BS 6883 offshore cables?

BS 6883 specifies flame-retardant (IEC 60332-3-22 Category A) elastomeric offshore cables without a mica fire barrier. BS 7917 adds a phlogopite mica-glass flame barrier over each conductor so the cable maintains circuit integrity during a 750 °C fire under IEC 60331-21.

BS 7917 U FR (Unarmoured Fire-Resistant) is a 600/1000 V offshore and marine circuit-integrity cable featuring Class 2 tinned copper conductors, phlogopite mica-glass fire barrier tape, GP4 EPR insulation and an oil- and mud-resistant SW4 (or reduced-propagati

IEC 60331-21 (750 °C)

SW4 Oil / Drilling Fluid

BS 7917 / UKOOA

Cores × mm²

Order designation: BS 7917 U FR 3×1.5 (UKOOA YD302)
Outer Ø ≈: 10.8 mm
Copper weight: 44 kg/km
Total weight ≈: 155 kg/km
Min. bend R: 65 mm

All sizes (14)

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Engineering reply in 2 business hoursCut-to-length export drumsEN 10204 3.1 certificate per drum

Rated voltage: 600/1000 V
Fire integrity: IEC 60331-21
Conductor: Tinned Cu Cl. 2
Insulation: Mica + GP4 EPR
Outer sheath: SW4 / SW2 LSZH
Min. bend radius: 6 × cable OD

Typical values for this cable type, based on BS 7917 / IEC 60331-21 — confirmed in the datasheet and quotation for your order.

Application fit

Is BS 7917 U FR right for your machine?

Designed for enclosed modules, accommodation quarters, control rooms and protected cable trays on fixed offshore oil & gas platforms, FPSOs and drilling vessels where reduced weight and IEC 60331 fire survival are required.

Offshore platform & shipboard deck trays

Suitable

SW4 cross-linked halogen-free elastomer sheath resists marine salt mist, fuel oils and hydraulic fluids.

Switchgear & control cabinet wiring

Suitable

Unarmoured profile routes cleanly into offshore switchgear, MCC cubicles and ESD emergency panels.

Fixed installation

Suitable

Approved for fixed tray and ladder routing across offshore production modules per UKOOA guidelines.

Motorised monospiral reel

Not suitable

Class 2 stranded tinned copper conductors and mica tape are strictly for fixed offshore wiring.

S07HXHX flexible LSZH

Typical machinesOffshore oil & gas platformsFPSO & FLNG vesselsSemi-submersible drilling rigsMarine engine & control roomsPetrochemical coastal terminals

Construction

Layer by layer

Class 2 tinned copper conductor + phlogopite mica-glass tape + GP4 EPR insulation + halogen-free tape/bedding + SW4/SW2 LSZH oil-resistant cross-linked elastomer outer sheath.

Schematic, not to scale — generated from the layer data

#	Layer	Material & reference
1	Tinned annealed copper	Circular stranded tinned copper conductor, Class 2 per BS EN 60228BS EN 60228
2	Mica-glass fire barrier	Helically lapped phlogopite mica-glass tape for 750 °C circuit integrityIEC 60331-21
3	GP4 EPR thermoset insulation	Ethylene propylene rubber (EPR) compound type GP4 per BS 7655-1.2BS 7655-1.2
4	Halogen-free binder tape	Low-smoke zero-halogen lapped binder tape over laid-up coresBS 7917
5	SW4 / SW2 offshore sheath	Cross-linked halogen-free oil-resistant elastomeric compound type SW4 (or SW2) per BS 7655-2.6BS 7655-2.6

BS 7917 U FR (SW4 Sheath)

Standard oil-resistant, low-smoke zero-halogen elastomeric outer sheath per BS 7655-2.6 Type SW4.

BS 7917 U FR (SW2 Enhanced Sheath)

Enhanced oil, drilling-fluid and tear-resistant elastomeric outer sheath per BS 7655-2.6 Type SW2.

Technical data

Ratings & operating limits

Typical values: Typical values for this cable type, based on BS 7917 / IEC 60331-21. Values for your order are confirmed in the datasheet and quotation.

Electrical

Rated voltage U0/U: 600/1000 V (power & control)
Routine AC test voltage: 3.5 kV rms for 5 minutes
Conductor resistance: BS EN 60228 Class 2 tinned copper

Thermal

Continuous conductor rating: +90 °C
Max. short-circuit temperature: +250 °C (5 s)
Fixed operating range: -40 °C to +90 °C
Min. installation temp.: -20 °C

Mechanical

Min. internal bend radius: 6 × overall diameter (OD ≤25 mm) · 8 × OD (>25 mm)
Tear & abrasion resistance: High-tear cross-linked SW4/SW2 elastomer

Resistance

Fire survival test: IEC 60331-21 (750 °C flame for 180 min + 15 min cool-down)
Bunched flame propagation: IEC 60332-3-22 Category A
Oil & fluid immersion: IRM 902 / IRM 903 mineral oil resistance per BS 7655-2.6

Reference standards

Offshore cable specification: BS 7917 & UKOOA Cable Code
Halogen & smoke emission: IEC 60754-1 (<0.5 % HCl) & IEC 61034-2 (≥60 % light transmittance)

Identification

Core identification: Numbered cores or colour-coded per BS 7917
Outer sheath colour: Orange (fire-resistant power) or Black

Sizes

14 standard configurations (BS 7917 U FR)

Nominal dimensions, masses and electrical ratings for BS 7917 U FR according to BS 7917 / IEC 60331-21.

Dimensions & masses
Designation	Cores × mm²	Cross-section	Outer Ø ≈ mm	Copper kg/km	Total weight ≈ kg/km	Min. bend R fixed mm
BS 7917 U FR standard series
BS 7917 U FR 2×1.5 (UKOOA YD202)	2×1.5	1.5 mm²	10.2	30	135	61
BS 7917 U FR 2×2.5 (UKOOA YD203)	2×2.5	2.5 mm²	11.2	49	170	67
BS 7917 U FR 3×1.5 (UKOOA YD302)	3×1.5	1.5 mm²	10.8	44	155	65
BS 7917 U FR 3×2.5 (UKOOA YD303)	3×2.5	2.5 mm²	11.9	74	200	71
BS 7917 U FR 3×4 (UKOOA YD304)	3×4	4.0 mm²	13.4	118	265	80
BS 7917 U FR 3×6 (UKOOA YD305)	3×6	6.0 mm²	14.8	176	345	89
BS 7917 U FR 3×10 (UKOOA YD306)	3×10	10 mm²	17.5	294	510	105
BS 7917 U FR 3×16 (UKOOA YD307)	3×16	16 mm²	19.8	470	715	119
BS 7917 U FR 4×1.5 (UKOOA YD402)	4×1.5	1.5 mm²	11.7	59	185	70
BS 7917 U FR 4×2.5 (UKOOA YD403)	4×2.5	2.5 mm²	12.9	98	240	77
BS 7917 U FR 4×4 (UKOOA YD404)	4×4	4.0 mm²	14.6	157	325	88
BS 7917 U FR 4×10 (UKOOA YD406)	4×10	10 mm²	19.2	392	635	115
BS 7917 U FR 7×1.5 (UKOOA YD702)	7×1.5	1.5 mm²	14.0	103	275	84
BS 7917 U FR 12×1.5 (UKOOA YDA02)	12×1.5	1.5 mm²	18.2	176	445	109

Typical values for this cable type; dimensions and weights for your order are confirmed in the quotation.
Nominal outer diameters and weights are subject to manufacturing tolerances per BS 7917 / IEC 60331-21.

Electrical data
Cores × mm²	Max. DC R @ 20 °C Ω/km	Current in air A	Current in duct/tray A
2×1.5	12.200	23	20
2×2.5	7.560	31	27
3×1.5	12.200	19	16
3×2.5	7.560	26	22
3×4	4.700	35	30
3×6	3.110	45	39
3×10	1.840	63	54
3×16	1.160	84	72
4×1.5	12.200	19	16
4×2.5	7.560	26	22
4×4	4.700	35	30
4×10	1.840	63	54
7×1.5	12.200	14	12
12×1.5	12.200	11	9

Current ratings apply at +30 °C ambient in free air and +25 °C in enclosed tray/conduit.

Quality & approvals

Testing & inspection

Routine tests on every production length, sample and type tests per batch — documented on an EN 10204 3.1 inspection certificate.

ConductorClass 5 stranding
Spark test100 % in-line
Lay-upCores, earth, fillers
SheathingInner, braid / screen, outer
Electrical testsAC voltage, resistance
DimensionsOD, wall thickness
Inspection documents & dispatchDrum & dispatch

Testing & inspection	Test value / reference	Frequency
Routine tests
3.5 kV AC dielectric withstand test	5 minutes at 3.5 kV rms without failure	100 % of drums
Sample tests
IEC 60331-21 circuit integrity in fire	180 minutes at ≥750 °C under rated voltage	BS 7917 type qualification
IEC 60332-3-22 Cat. A bunched vertical flame test	Char height ≤2.5 m with 7 l/m non-metallic volume	BS 7917 type qualification

Inspection certificate

Issued with every drum, listing the routine test results for that length.

Product approvals

BS 7917UKOOA Offshore Cable CodeIEC 60331-21 (750 °C, 3 h)IEC 60332-3-22 Cat. ABS 7655-1.2 GP4 & BS 7655-2.6 SW4

Company certificates

ISO 9001ISO 14001ISO 45001VDE marks approvalUL / cULCE · LVD / EMC

Marking & supply

Ordering & delivery

Sheath marking

TEBAOFLEX BS 7917 600/1000V FIRE RESISTANT 4x2.5mm2 GP4/SW4 IEC 60331-21 IEC 60332-3-22 [year] [meter mark]

Delivery form: Fumigated export wooden drums or shrink-wrapped coils
Standard drum lengths: 500 m · 1000 m standard drums (cut lengths on request)
MOQ: 100 m (stock sizes) · 300–500 m (production)
Lead time: 2–4 weeks ex-works
Incoterms: EXW, FOB, CIF, DAP

Technical documents

Downloads

PDFBS 7917 U FR Unarmoured Fire-Resistant Offshore Power Cable – technical datasheet14 sizes · construction, technical data, approvals XLSXBS 7917 U FR spec data (Excel)All 14 sizes with dimensions and data, for your BOM or quotation

Revision: 2026-10-20
Updated: 2026-10-20

FAQ

Questions engineers ask first

Not covered here? Send your drawing — an engineer replies within 2 business hours.

When is unarmoured BS 7917 U FR chosen over wire-braid armoured BS 7917 A FR?

BS 7917 U FR is specified inside enclosed offshore accommodation modules, switchgear rooms and protected internal cable trays where external mechanical impact risk is controlled and topside weight reduction is a priority.

Why are tinned copper conductors mandatory in BS 7917 offshore cables?

Offshore platforms and FPSOs operate in salt-laden humid atmospheres containing hydrogen sulphide (H2S). Tin plating prevents copper sulphide corrosion on individual strands and ensures low-resistance crimp terminations over a 25-year offshore design life.

What is the difference between SW4 and SW2 outer sheath compounds in BS 7917?

Both SW4 and SW2 are cross-linked halogen-free elastomeric compounds to BS 7655-2.6. SW4 provides standard oil resistance and low smoke emission, whereas SW2 offers enhanced tear strength, reduced flame propagation and superior swelling resistance against ester-based drilling muds.

What is the difference between BS 7917 and BS 6883 offshore cables?

BS 6883 specifies flame-retardant (IEC 60332-3-22 Category A) elastomeric offshore cables without a mica fire barrier. BS 7917 adds a phlogopite mica-glass flame barrier over each conductor so the cable maintains circuit integrity during a 750 °C fire under IEC 60331-21.

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BS 7917 U FR Unarmoured Fire-Resistant Offshore Power Cable

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Datasheet Request a quote

BS 7917 U FR Unarmoured Fire-Resistant Offshore Power Cable0.6/1 kV (600/1000 V) unarmoured fire-resistant offshore power & control cable (Mica/EPR/S

Offshore platform & shipboard deck trays

Switchgear & control cabinet wiring

Fixed installation

Motorised monospiral reel

BS 7917 U FR (SW4 Sheath)

BS 7917 U FR (SW2 Enhanced Sheath)

Electrical

Thermal

Mechanical

Resistance

Reference standards

Identification

Inspection certificate

Product approvals

Company certificates

01Selected sizes

02Reel & motion

03Message for our engineers

BS 7917 A FR

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S07HXHX

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