BS 6708 Type 307 1.9/3.3kV Heavy-Duty Screened Mining Cable for Excavating & Crushing Machines
APPLICATION
Used for supplying excavating, crushing machines and equipment.
Cable Structure
CONDUCTOR : Electrolytic, stranded, tinned copper wire IEC 60228 Class 5
INSULATION : EPR (Ground core is not insulated).
SEPERATOR : Colored Textile tape for core identification.
SCREEN : Tinned copper / Nylon braided screen over phase cores. Pilot core is not screened.
LAYUP : All cores are laid up in contact with the bare copper earth conductor.
BEDDING : Rubber based bedding compound.
OUTER SHEATH : Heavy duty chloroprene outer sheath.
Cable Properties
RELATED STANDARDS : BS 6708
RATED VOLTAGE : 1,9/3,3 kV
TEST VOLTAGE : 7,5 kV
Technical Specifications
Cross Section | 3×25+25+16 | 3×35+25+16 | 3×50+35+25 | 3×70+50+35 | 3×95+50+50 | 3×120+70+70 | 3×150+70+95 | |
|---|---|---|---|---|---|---|---|---|
Phase Conductor | ||||||||
Number and cross section | mm2 | 3×25 | 3×35 | 3×50 | 3×70 | 3×95 | 3×120 | 3×150 |
Insulation diameter | Nom. mm | 13.10 | 14.70 | 15.70 | 17.70 | 19.10 | 21.40 | 23.00 |
Screen diameter | Nom. mm | 15.50 | 17.10 | 17.70 | 19.70 | 21.10 | 23.40 | 25.00 |
Earth Conductor | ||||||||
Number and cross section | mm2 | 1×25 | 1×25 | 1×35 | 1×50 | 1×50 | 1×70 | 1×95 |
Stranding | mm | 196/0,40 | 196/0,40 | 276/0,40 | 396/0,40 | 396/0,40 | 360/0,50 | 475/0,50 |
Conductor diameter | Nom. mm | 7.00 | 7.00 | 8.50 | 10.00 | 10.00 | 11.70 | 13.50 |
Pilot Conductor | ||||||||
Number and cross section | mm2 | 1×16 | 1×16 | 1×25 | 1×35 | 1×50 | 1×70 | 1×95 |
Stranding | mm | 126/0,40 | 126/0,40 | 196/0,40 | 276/0,40 | 396/0,40 | 360/0,50 | 475/0,50 |
Conductor diameter | Nom. mm | 5.50 | 5.50 | 7.00 | 8.50 | 10.00 | 11.70 | 1.35 |
Insulation diameter | Nom. mm | 11.60 | 11.60 | 13.10 | 14.70 | 15.70 | 17.70 | 19.10 |
Cable details | ||||||||
Min. overall diameter | mm | 47.4 | 51.6 | 56.8 | 62.8 | 68.9 | 73.4 | 75.9 |
Max. overall diameter | mm | 49.9 | 54.6 | 59.8 | 65.8 | 72.7 | 77.2 | 79.7 |
Min. bending radius | mm | 400 | 440 | 480 | 525 | 580 | 615 | 640 |
Max. pulling tension | kgf | 640 | 830 | 1.2 | 1.68 | 2 | 2 | 2 |
Appx. cable weight | kg/km | 4 | 4.8 | 6.15 | 7.6 | 9.25 | 11.2 | 13 |
Copper weight | kg/km | 1.654 | 1.948 | 2.666 | 3.482 | 4.346 | 5.45 | 6 |
Electrical details | ||||||||
Continuous current | A | 110 | 135 | 170 | 205 | 250 | 295 | 320 |
Intermittent current | A | 130 | 155 | 210 | 255 | 315 | 360 | 385 |
Max. DC resistance at 20°C | ||||||||
Phase Conductor | Ω /km | 0.795 | 0.565 | 0.393 | 0.277 | 0.21 | 0.164 | 0.132 |
Pilot Conductor | Ω /km | 1.24 | 1.24 | 0.795 | 0.565 | 0.393 | 0.277 | 0.21 |
3 screens and earth in parallel connection | Ω /km | 0.5 | 0.5 | 0.35 | 0.35 | 0.28 | 0.28 | 0.14 |
Nom. reactance at 50Hz | Ω /km | 0.125 | 0.117 | 0.113 | 0.108 | 0.105 | 0.101 | 0.098 |
Nom. reactance at 60Hz | Ω /km | 0.15 | 0.141 | 0.136 | 0.129 | 0.126 | 0.121 | 0.118 |
Min. insulation | M Ω /km | 1250 | 1100 | 950 | 820 | 720 | 660 | 600 |
3 phase voltage drop on full load current | mV/A/m | 1.69 | 1.21 | 0.85 | 0.61 | 0.48 | 0.39 | 0.32 |
When mining operations demand reliable medium-voltage power, extreme mechanical durability, and enhanced electrical safety, choosing the right trailing cable becomes critical. One cable type frequently specified for excavators, crushers, and heavy mobile equipment is the BS 6708 Type 307 1.9/3.3kV heavy-duty screened mining cable.
What Is BS 6708 Type 307 Mining Cable Designed For?
BS 6708 Type 307 is a medium-voltage (1.9/3.3kV) screened mining trailing cable designed to supply excavating, crushing, and processing machinery operating under severe mechanical and environmental stress.
It is primarily used where:
Equipment is mobile or semi-mobile
Cables are subject to dragging, bending, vibration, and impact
Enhanced earth fault protection and operator safety are required
Typical applications include:
Excavators and bucket wheel reclaimers
Mobile crushers and screeners
Mineral processing plants
Conveyor head drives and feeders
How Does BS 6708 Type 307 Compare with Other Mining Cables?
Feature | Type 307 | Type 43 | Type 730 |
|---|---|---|---|
Voltage Level | 1.9/3.3 kV | 125/72 V | 3.8/6.6 kV |
Screened Cores | Yes | No | Yes |
Typical Equipment | Excavators, crushers | Hand-held tools | Large mining machines |
Mechanical Strength | Very High | Medium | Very High |
Safety Level | High | Basic | Very High |
Type 307 fills the gap between low-voltage tool cables and higher-voltage heavy machine cables, making it extremely versatile.
Frequently Asked Questions (FAQ)
Is BS 6708 Type 307 suitable for continuous trailing applications?
Yes. It is specifically designed for continuous flexing, dragging, and reeling in mining environments.
Why is the pilot core included?
The pilot conductor enables:
Earth continuity monitoring
Interlocking systems
Rapid shutdown in fault conditions
This is essential for modern mining safety systems.
Can BS 6708 Type 307 replace armoured mining cables?
In many mobile applications, yes. Its screened and heavy-duty design provides protection without the stiffness of armour.
Why Should You Choose BS 6708 Type 307 for Excavating and Crushing Equipment?
BS 6708 Type 307 offers a balanced combination of:
Electrical safety
Mechanical durability
Flexibility
Proven performance in African mining conditions
It is an engineering-driven solution rather than a generic power cable.
How Can You Select the Right BS 6708 Type 307 Cable?
Choosing the correct cable size and configuration requires:
Load calculation
Installation method review
Environmental assessment
👉 Consult with an experienced mining cable supplier or technical engineer to ensure compliance, safety, and long-term reliability for your specific application.
