mining cables may be sheathed in robust rubber to provide abrasion resistance, especially for trailing applications, the BS6622 and BS7835 standard cables are instead sheathed in PVC or LSZH materials, with mechanical protection provided from a layer of steel wire armouring. As a British standard voltage, 8.7/15kV isn’t as commonly specified as 11kV or 33kV, but will depend on the application demands.
6.35/11kV voltage is commonly associated with armoured cable – the aluminium wire armour (AWA) for single core cables and steel wire armour (SWA) for multicore cables providing robust mechanical protection that makes 11kV cables suitable for direct burial in the ground. These armoured MV mains power cables are more commonly supplied with copper conductors but they are also available with aluminium conductors upon request to the same standard.