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non-armoured mining cable

20 Min Read
Type 7S is a single-core, flexible mining machine cable designed for direct connection to motor terminals and equipment in high-vibration underground environments. When a specification calls for "Type 7S 3.3kV 3x70mm²," it refers to three separate, individual single-core cables (each one being 1x70mm² in cross-section), which are installed in trefoil formation (arranged in a triangular pattern) to create a complete three-phase power system for a conveyor drive motor. Each single core has its own 360-degree copper screening layer, Class 5 extra-flexible stranded conductors, and a signature glass fiber braid reinforcement layer that provides superior vibration and thermal resistance. This combination makes Type 7S the preferred cable choice for main conveyor systems in underground coal mines, where the motor is subject to continuous high-frequency vibration, the terminal space is confined, and flexibility is essential for reliable long-term operation.
Technical Department
on06/03/2026

Conveyor Belt Power: Specifying Type 7S 3.3kV 3x70mm² for Underground Coal Conveyors

Type 7S is a single-core, flexible mining machine cable designed for direct connection to motor terminals and equipment in high-vibration underground environments. When a specification calls for “Type 7S 3.3kV 3x70mm²,” it refers to three separate, individual single-core cables (each one being 1x70mm² in cross-section), which are installed in trefoil formation (arranged in a triangular pattern) to create a complete three-phase power system for a conveyor drive motor. Each single core has its own 360-degree copper screening layer, Class 5 extra-flexible stranded conductors, and a signature glass fiber braid reinforcement layer that provides superior vibration and thermal resistance. This combination makes Type 7S the preferred cable choice for main conveyor systems in underground coal mines, where the motor is subject to continuous high-frequency vibration, the terminal space is confined, and flexibility is essential for reliable long-term operation.
5 Min Read
Type 7 Mining Cable to BS 6708
Technical Department
on15/11/2025

What is Type 7 Mining Cable to BS 6708?

Type 7 mining cables represent a critical category of flexible trailing cables designed specifically for the demanding conditions encountered in underground coal mining operations. These cables conform to the rigorous requirements established by British Standard BS 6708, which has become an internationally recognized benchmark for mining cable safety and performance. The standard was developed through decades of mining industry experience and addresses the unique electrical and mechanical challenges present in potentially explosive underground environments. According to BSI Knowledge, BS 6708 specifications establish comprehensive requirements for flexible cables used at mines and quarries, ensuring that these critical power transmission components meet stringent safety and performance criteria. The Type 7 designation specifically identifies non-armoured cables with individually metallic screened cores rated at 640/1100V, engineered for both fixed installation and flexible operation in coal face cutting equipment.