BS 6708 Type 7M 640/1100V Heavy-Duty Mining Power Cable with EPR Insulation & Chloroprene Sheath

What Does the BS 6708 Type 7M Standard Mean for Mining Cables?

BS 6708 is a British Standard specifically developed for flexible trailing and power cables used in mining and quarrying operations. Within this standard, Type 7M refers to a heavy-duty screened mining power cable designed for:

• High mechanical stress

• Continuous flexing and dragging

• Wet, abrasive, and chemically aggressive environments

Unlike general industrial flexible cables, BS 6708 Type 7M mining cables are engineered for mobile heavy equipment, such as excavators and crushers, where failure directly causes downtime and safety risks.

How Is the BS 6708 Type 7M Mining Cable Constructed?

The performance of a mining cable starts with its internal design. BS 6708 Type 7M uses a layered construction, each element serving a specific mechanical or electrical function.

What Type of Conductor Is Used in BS 6708 Type 7M?

• Electrolytic tinned copper

• Stranded Class 5 conductor (IEC 60228)

This design ensures:

• Excellent flexibility for trailing applications

• Reduced oxidation due to tinning

• Stable conductivity under vibration and movement

Both phase and pilot conductors use the same high-quality copper stranding for consistent electrical behavior.

Why Is EPR Insulation Used in Type 7M Mining Cables?

The insulation material is EPR (Ethylene Propylene Rubber), a preferred choice for mining environments because it offers:

• High dielectric strength

• Superior heat resistance

• Excellent resistance to moisture and chemicals

What Is the Function of the Screen and Bedding Layers?

• Screen:

  • Tinned copper / nylon braided screen over phase and pilot cores

  • Enhances earth fault protection

  • Reduces electromagnetic interference

• Bedding:

  • Rubber-based compound

  • Absorbs mechanical stress

  • Maintains cable geometry under load

Why Is a Chloroprene Outer Sheath Used?

The outer sheath is made from heavy-duty chloroprene rubber (CR), known for:

• High abrasion resistance

• Oil and grease resistance

• UV and ozone stability

• Flame retardant properties

This makes the cable ideal for open-pit and underground mining environments where cables are dragged across rough surfaces.

How Does BS 6708 Type 7M Compare with Other Mining Cables?

Type 7M is chosen when mechanical abuse and electrical safety are critical.

Where Is BS 6708 Type 7M Commonly Used in Mining?

Typical Applications Include:

• Excavators

• Crushing plants

• Mobile screening equipment

• Heavy quarry machinery

• Surface and underground mining power supply

What Should Be Considered When Installing BS 6708 Type 7M Mining Cables?

Recommended Installation Practices

• Respect minimum bending radius (309–627 mm depending on size)

• Avoid sharp edges and unsupported spans

• Use proper cable handling rollers

• Ensure correct earth continuity checks before energizing

Why Choose BS 6708 Type 7M for Heavy-Duty Mining Equipment?

BS 6708 Type 7M combines:

• Proven British mining standards

• High mechanical durability

• Stable electrical performance

• Field-proven reliability in South African mines

It is a cost-effective, long-term solution for demanding mining power applications.

If you are selecting mining power cables for excavators, crushers, or heavy mobile equipment, choosing the correct BS 6708 Type 7M configuration is critical.

👉 Contact a professional mining cable supplier to:

• Confirm conductor sizing

• Verify compliance for your mine

• Optimize cable lifespan and safety