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Mining trailing & reeling cablesBS 6708 Type 7303,800/6,600 V · 35–150 mm²Screened Non-Armoured MV Trailing

BS 6708 Type 730 MV Trailing Cable (3,800/6,600 V)3,800/6,600 V screened non-armoured medium-voltage mining trailing cable (35–150+16 mm²)

BS 6708 Type 730 3,800/6,600 V (3.8/6.6 kV) flexible non-armoured mining trailing cable with three individually copper/nylon braided-screened 5.0 mm EPR phase cores, central bare earth on 120–150 mm², and heavy-duty PCP sheath.

EMC screen
Flame-retardant
Oil-resistant
Water-resistant
Order designation
3 × 70
Phase size
70 mm²
Current (25 °C)
205 A
Max. OD
71.4 mm
Mass ≈
7,100 kg/km
Check against my drumAll sizes (6)
Request a quoteDatasheetWhatsApp
Engineering reply in 2 business hoursCut-to-length export drumsEN 10204 3.1 certificate per drum
Rated voltage
3,800/6,600 V
15 kV AC routine test
Core arrangement
3P (scr) ± 16E
Mutual-contact screens
Phase size range
35–150 mm²
6 standard sizes
Ampacity (25 °C)
135–320 A
Continuous ambient rating
Operating temp.
−25 to +85 °C
5.0 mm EPR + PCP
Min. bend radius
10 × OD (605+)
Unarmoured flexible

Typical values for this cable type, based on BS 6708 · IEC 60228 Class 5 — confirmed in the datasheet and quotation for your order.

Application fit

Is BS 6708 Type 730 (3.8/6.6 kV) right for your machine?

Designed as a 3,800/6,600 V screened non-armoured trailing cable for large movable underground and open-cast mining machines where rough usage is expected and tighter bending flexibility (10 × OD) than wire-armoured Type 630/631 is required.

Trailing & towing

Suitable

Primary 3.8/6.6 kV flexible trailing cable for large movable mining and quarry machinery.

Cylindrical / multi-layer drum

Suitable

Unarmoured construction achieves a 10 × OD minimum bending radius (605–860 mm) and 30–45% lower mass than Type 630.

Fixed installation

With conditions

6.0–8.0 mm heavy-duty PCP sheath resists rough floor drag; for severe rockfall or crush zones use pliable-armoured Type 630/631.

Immersion & wet locations

Suitable

5.0 mm EPR dielectric and heavy-duty chloroprene jacket withstand wet mine faces, oil and abrasion.

Free-hanging vertical run

Not suitable

Flexible unarmoured trailing construction — do not suspend in deep vertical mine shafts without support.

Use BS 6708 Type 20/21 Armoured
Typical machinesLarge 6.6 kV movable mining machinesQuarry & open-cast electric face shovelsHigh-capacity 6.6 kV longwall shearersMobile primary crusher & dragline feedersHeavy 6.6 kV mine dewatering skidsRough-service MV trailing interconnections

Construction

Layer by layer

Three flexible IEC 60228 Class 5 tinned copper phase conductors (35–150 mm²) insulated with 5.0 mm EPR, wrapped with coloured identification textile tape and individually screened with a composite tinned-copper/nylon braid are laid up in mutual contact (around a bare central 1×16 mm² tinned copper earth conductor on 120 and 150 mm² sizes), enclosed by an elastomeric rubber bedding and a 6.0–8.0 mm heavy-duty chloroprene outer sheath.

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Schematic, not to scale — generated from the layer data
#LayerMaterial & reference
1Flexible phase conductors (3)Electrolytic stranded tinned copper wire, IEC 60228 Class 5 (35 to 150 mm², 276/0.40 to 756/0.50 mm)IEC 60228 Class 5
25.0 mm EPR medium-voltage insulationEthylene propylene rubber (EPR) dielectric, 5.0 mm nominal radial wall across all sizes (15 kV AC routine test)BS 6708 (15 kV test)
3Coloured textile identification tapeColour-coded textile separator tape over EPR insulation under each core screenBS 6708
4Composite copper / nylon braided phase screenTinned copper wire and nylon braided screen over each phase core, laid up in mutual contact (0.26–0.81 Ω/km combined with earth)BS 6708
5Central bare earth conductor (120 & 150 mm²)1×16 mm² (126/0.40 mm, 5.50 mm Ø) bare Class 5 tinned copper earth conductor in contact with the 3 core screens on 3×120+16 and 3×150+16BS 6708
6Rubber inner beddingExtruded elastomeric rubber bedding filling interstices and cushioning the screened core assemblyBS 6708
7Heavy-duty chloroprene outer sheathHeavy-duty flame-retardant polychloroprene (chloroprene / PCP, 6.0 to 8.0 mm radial wall)BS 6708

BS 6708 Type 730 · 3×35 to 3×95 mm²

3 individually copper/nylon braided-screened 5.0 mm EPR phase cores laid in mutual contact (0.42–0.81 Ω/km screen earth path)

BS 6708 Type 730 · 3×120+16 & 3×150+16 mm²

3 individually screened 5.0 mm EPR phase cores + central 1×16 mm² (126/0.40 mm) bare copper earth core (0.26–0.32 Ω/km)

Technical data

Ratings & operating limits

Typical values: Typical values for this cable type, based on BS 6708 · IEC 60228 Class 5. Values for your order are confirmed in the datasheet and quotation.

Electrical

Rated voltage U0/U
3,800/6,600 V (3.8/6.6 kV) AC · 15 kV routine AC test voltage
Current rating (25 °C)
135 A (35 mm²) to 320 A (150 mm²) continuous at 25 °C ambient
Phase & screen/earth DC resistance
Phase conductors: 0.565–0.132 Ω/km at 20 °C · 3 screens + earth in parallel: 0.81–0.26 Ω/km at 20 °C

Thermal

Ambient temperature range
−25 °C to +85 °C
Max. conductor temperature
+90 °C continuous EPR operating temperature (250 °C short-circuit)

Mechanical

Min. bending radius
10 × Maximum Overall Diameter (605 mm on 3×35 mm² to 860 mm on 3×150+16 mm²)
Bedding & outer sheath
Rubber bedding compound + 6.0 to 8.0 mm heavy-duty chloroprene (PCP) outer sheath (57.5–86.0 mm OD)

Resistance

Trailing abrasion & tear resistance
Unarmoured flexible construction with 6.0–8.0 mm heavy-duty chloroprene jacket resists rough quarry & mine floor drag
Flame, oil & water
Heavy-duty flame-retardant and oil-resistant chloroprene (PCP) outer sheath for wet underground & surface mining

Reference standards

Construction standard
BS 6708 (3,800/6,600 V screened non-armoured mining trailing cable — Type 730)
Conductor & insulation
IEC 60228 Class 5 flexible tinned copper · 5.0 mm EPR insulation · composite Cu/nylon braided core screens
Routine voltage test
15 kV AC routine dielectric test on all 3,800/6,600 V phase cores

Identification

Core identification
Coloured textile separator tape over EPR insulation under each tinned-copper/nylon braided phase screen
Central earth conductor
3×35 to 3×95 mm²: 3 screened cores · 3×120+16 & 3×150+16 mm²: adds central bare 16 mm² (126/0.40 mm) tinned copper earth

Sizes

6 standard configurations from 3×35 mm² to 3×150+16 mm² (BS 6708 Type 730 · 3,800/6,600 V)

Complete dimensional, mechanical and electrical schedule per BS 6708.

Dimensions & electrical
Designation
mm²		Phase
mm²		Phase strand
n/mm		Phase Ø
mm		EPR wall
mm		Central earth
mm² (strand · Ø)		Outer wall
mm		Min. OD
mm		Max. OD
mm		Min. bend
mm		Current 25 °C
A		Phase DC 20 °C
Ω/km		3 scr + earth
Ω/km		Cu mass
kg/km		Mass ≈
kg/km		Enquiry
3 × 3535276/0.408.405.0— (3 screens)6.057.560.56051350.5650.811,3004,800
3 × 5050396/0.4010.105.0— (3 screens)6.362.065.06501700.3930.781,8005,900
3 × 7070360/0.5011.905.0— (3 screens)6.867.571.47142050.2770.552,5007,100
3 × 9595475/0.5013.905.0— (3 screens)7.373.176.97692500.2100.423,2508,500
3 × 120 + 16120608/0.5015.505.01×16 (126/0.40 · 5.50 Ø)7.676.980.98092950.1640.324,2009,950
3 × 150 + 16150756/0.5017.205.01×16 (126/0.40 · 5.50 Ø)8.082.186.08603200.1320.265,00011,400
  • Typical values for this cable type; dimensions and weights for your order are confirmed in the quotation.
  • On 3×35 to 3×95 mm², the three tinned-copper/nylon braided phase screens laid in mutual contact form the protective earth path (0.42–0.81 Ω/km). On 3×120+16 and 3×150+16 mm², a central bare 1×16 mm² (126/0.40 mm) tinned copper earth conductor is laid in contact with all three screens.
  • Minimum bending radius is 10 × Maximum Overall Diameter across all sizes.

Reel check

Will it fit your machine?

A first screen using datasheet values. Engineering confirms drum geometry, acceleration and tension with your quotation.

Check results

Enter your drum core diameterMinimum for this size is about 1,428 mm
Minimum bending radius
714 mm
Min. drum core diameter
≈ 1,428 mm
Cable weight on drum
710.0 kg
Outer diameter
71.4 mm
Indicative only: based on the datasheet outer diameter and 10 × OD bending radius. Current derating for wound layers per DIN VDE 0298-4 is assessed separately.

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.

  1. ConductorClass 5 stranding
  2. Spark test100 % in-line
  3. Lay-upCores, earth, fillers
  4. SheathingInner, braid / screen, outer
  5. Electrical testsAC voltage, resistance
  6. DimensionsOD, wall thickness
  7. Inspection documents & dispatchDrum & dispatch
Testing & inspectionTest value / referenceFrequency
Routine tests
15 kV AC high-voltage dielectric test15 kV AC routine voltage withstand test on 3,800/6,600 V 5.0 mm EPR phase cores per BS 6708Every shipping drum
Phase conductor & parallel screens/earth DC resistanceMax. 0.565–0.132 Ω/km on phase conductors and 0.81–0.26 Ω/km on 3 screens + earth in parallel at 20 °CEvery shipping drum
Sample tests
Heavy-duty PCP sheath flame, oil & tear test6.0–8.0 mm chloroprene outer sheath tested for rough movable mining service per BS 6708Production batch

Inspection certificate

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

Product approvals

BS 6708 Type 730CE · LVDRoHS · REACH

Company certificates

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

Marking & supply

Ordering & delivery

Sheath marking

TEBAOFLEX · BS 6708 · TYPE 730 · 3800/6600V
Delivery form
Export seaworthy fumigated wooden drums matched to 10 × OD bend radius
Lengths
Standard drum lengths or custom cut trailing lengths
Certificate
EN 10204 3.1 factory routine test certificate with every drum
Quote response
Engineering specification and quote within 2 business hours

Technical documents

Downloads

PDFBS 6708 Type 730 MV Trailing Cable (3,800/6,600 V) – technical datasheet6 sizes · construction, technical data, approvalsXLSXBS 6708 Type 730 (3.8/6.6 kV) spec data (Excel)All 6 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.

How does BS 6708 Type 730 differ from Type 630 and Type 631?
All three are 3,800/6,600 V (3.8/6.6 kV) BS 6708 mining cables with individually copper/nylon braided-screened 5.0 mm EPR phase cores tested at 15 kV AC. Type 730 is an unarmoured flexible trailing cable (10 × OD bend radius, 4,800–11,400 kg/km) for large movable machines, whereas Type 630 and Type 631 include a pliable galvanised steel wire armour layer (12 × OD bend radius, 8,400–21,200 kg/km).
Why do only the 120 mm² and 150 mm² sizes include a separate 16 mm² earth conductor?
On 3×35 to 3×95 mm², the three tinned-copper/nylon braided phase screens laid in mutual contact provide sufficient earth-fault conductance (0.42–0.81 Ω/km). On 3×120+16 and 3×150+16 mm², adding a central bare 1×16 mm² (126/0.40 mm) tinned copper conductor in contact with the screens lowers the combined earth path resistance to 0.32 and 0.26 Ω/km to match the higher phase fault levels.
What is the minimum bending radius for BS 6708 Type 730?
The minimum bending radius is 10 × Maximum Overall Diameter across all sizes, from 605 mm on 3×35 mm² (60.5 mm max OD) to 860 mm on 3×150+16 mm² (86.0 mm max OD).
What routine voltage test is performed on BS 6708 Type 730?
Every production length of BS 6708 Type 730 is subjected to a 15,000 V (15 kV) AC dielectric test on the 5.0 mm EPR-insulated phase cores.

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BS 6708 Type 730 MV Trailing Cable

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