BS 6708 Type 331 1900/3300V Armoured Mining & Trailing Cable for Excavating and Crushing Equipment with EPR Insulation, Screened Cores and Heavy-Duty Chloroprene Sheath
APPLICATION:
Used for supplying excavating, crushing machines and equipment. Can also be used as trailing cable in quarries.
Cable Structure:
CONDUCTOR : Electrolytic, stranded, tinned copper wire IEC 60228 Class 5
INSULATION : EPR
SCREEN : Tinned copper / Nylon braided screen over phase cores. Ground core is not screened.
LAYUP : All cores are laid up in contact with each other.
BEDDING : Rubber based bedding compound.
ARMOUR : Galvanized steel pliable armour.
OUTER SHEATH : Heavy duty chloroprene outer sheath.
Cable Properties:
RELATED STANDARDS : BS 6708
RATED VOLTAGE : 1900/3300 V
TEST VOLTAGE : 7,5 kV
Technical Specifications:
Cross Section | 3×25+16 | 3×35+25 | 3×50+35 | 3×70+50 | 3×95+70 | 3×120+70 | |
|---|---|---|---|---|---|---|---|
Phase Conductors | |||||||
Number and cross section | mm2 | 3×25 | 3×35 | 3×50 | 3×70 | 3×95 | 3×120 |
Insulation thickness | mm | 3.0 | 3.0 | 3.0 | 3.0 | 3.0 | 3.0 |
Phase Conductors | |||||||
Number and cross section | mm2 | 1×16 | 1×25 | 1×35 | 1×50 | 1×70 | 1×70 |
Stranding | mm | 126/0,40 | 196/0,40 | 276/0,40 | 396/0,40 | 360/0,50 | 360/0,50 |
Conductor diameter | Nom. mm | 5.50 | 7.10 | 8.40 | 10.10 | 11.90 | 11.90 |
Insulation thickness | mm | 3.0 | 3.0 | 3.0 | 3.0 | 3.0 | 3.0 |
Cable details | |||||||
Radial thickness of inner sheath | mm | 2.5 | 3.8 | 3.8 | 5.0 | 5.0 | 5.0 |
Min. inner sheath diameter | mm | 42.2 | 48.2 | 52.5 | 60.0 | 65.1 | 68.8 |
Max. inner sheath diameter | mm | 44.7 | 50.7 | 55.6 | 63.0 | 68.9 | 72.6 |
Size of armour | mm | 7/0,90 | 7/0,90 | 7/0,90 | 7/1,25 | 7/1,25 | 7/1,25 |
Outer sheath thickness | mm | 5.1 | 5.5 | 5.9 | 6.4 | 6.9 | 7.3 |
Min. overall diameter | mm | 57.8 | 64.6 | 69.8 | 80.3 | 86.4 | 90.9 |
Max. overall diameter | mm | 61.6 | 68.4 | 73.8 | 84.6 | 90.7 | 95.2 |
Min. bending radius | mm | 740 | 821 | 886 | 1.016 | 1.089 | 1.143 |
Appx. cable weight | kg/km | 6.8 | 8.5 | 9.75 | 15.6 | 18.1 | 20.05 |
Copper weight | kg/km | 1.164 | 1.522 | 2.196 | 3.036 | 4.028 | 4.758 |
Electrical details | |||||||
“Continuous current | A | 110 | 135 | 170 | 205 | 250 | 295 |
Max. DC resistance at 20°C | |||||||
Phase conductors | Ω /km | 0.795 | 0.565 | 0.393 | 0.277 | 0.210 | 0.164 |
Earth conductor | Ω /km | 1.24 | 0.795 | 0.565 | 0.393 | 0.277 | 0.277 |
Armour | Ω /km | 0.965 | 0.844 | 0.715 | 0.488 | 0.382 | 0.299 |
3 screens in parallel connection | Ω /km | 1.35 | 0.80 | 0.70 | 0.69 | 0.64 | 0.55 |
When heavy mining machinery such as excavators, crushers, and mobile processing units operates in harsh environments, power supply reliability is not optional — it is critical. This is where BS 6708 Type 331 1900/3300V armoured mining and trailing cable plays a vital role.
Designed for medium-voltage mobile equipment, Type 331 combines EPR insulation, screened phase cores, galvanised steel armour, and a heavy-duty chloroprene sheath to withstand mechanical abuse, electrical stress, and environmental exposure. But what exactly makes this cable suitable for demanding mining and quarry operations, especially in regions such as Southern Africa?
What Is BS 6708 Type 331 and Where Does It Fit Within Mining Cable Standards?
BS 6708 is a British Standard specifically developed for flexible cables used in mining and quarrying applications. Within this standard, Type 331 is classified as a medium-voltage armoured mining and trailing cable rated at 1900/3300V.
Type 331 is engineered for:
Supplying excavating equipment
Powering crushing and screening plants
Acting as a trailing cable in quarries
Operating in abrasive, high-impact, and mobile conditions
Unlike lower-voltage mining cables, Type 331 supports higher power transmission, making it ideal for larger machines with higher starting currents and continuous loads.
Where Is BS 6708 Type 331 Commonly Used in Practice?
Typical Applications
BS 6708 Type 331 is widely used for:
Excavators and bucket wheel machines
Mobile crushers and screens
Conveyor drive systems
Quarry trailing cable applications
Semi-fixed mining plant power feeds
Its flexibility combined with mechanical strength makes it ideal for equipment that moves frequently but still requires medium-voltage power.
How Is BS 6708 Type 331 Used in South African Mining Operations?
Real-World Case: Quarry Crushing Plant in Limpopo Province
In a hard-rock quarry in Limpopo, South Africa, operators faced repeated cable failures due to:
Sharp rock edges
Continuous dragging of trailing cables
High motor starting currents
After switching to BS 6708 Type 331 3×70+50 mm², the operation reported:
Reduced unplanned downtime
Improved electrical stability during crusher start-up
Longer service life compared to lower-voltage alternatives
Improved compliance with mine safety inspections
The screened EPR insulation and steel armour proved essential in maintaining reliability under real mining conditions.
How Does BS 6708 Type 331 Compare with Other BS 6708 Mining Cables?
Model Comparison Table
Cable Type | Voltage | Screening | Typical Use |
|---|---|---|---|
Type 201 | 640/1100V | No | Small excavators |
Type 211 | 640/1100V | Yes | Medium mobile equipment |
Type 321 | 1900/3300V | No | MV fixed supply |
Type 331 | 1900/3300V | Yes | MV mobile & trailing |
Type 331 is the preferred choice when:
Medium voltage is required
Equipment is mobile
Electrical safety and stability are critical
Frequently Asked Questions (FAQ)
Is BS 6708 Type 331 suitable for continuous trailing use?
Yes. It is designed specifically for trailing and mobile mining equipment, provided bending radius and mechanical limits are respected.
Why is the earth core not screened?
The unscreened earth core simplifies grounding while the phase screening handles electric field control, ensuring safe medium-voltage operation.
Can BS 6708 Type 331 replace lower-voltage mining cables?
Only when equipment voltage and insulation coordination allow. It is not a drop-in replacement for 640/1100V systems without proper engineering checks.
Is Type 331 resistant to oil and sunlight?
Yes. The chloroprene outer sheath offers excellent resistance to oils, grease, UV, and weathering.
Why Choose BS 6708 Type 331 for Modern Mining Projects?
BS 6708 Type 331 delivers:
Medium-voltage power capability
Enhanced electrical safety via screened cores
Mechanical durability for harsh environments
Proven performance in South African mining and quarrying
Compliance with internationally recognised mining standards
For operations seeking reliability, safety, and long service life, Type 331 is a technically sound and field-proven solution.
If you are specifying, upgrading, or replacing mining power cables for excavators, crushers, or quarry equipment, BS 6708 Type 331 deserves serious consideration.
Consult with experienced mining cable suppliers to ensure correct sizing, compliance, and installation support for your project.
