Whilst BS7671 has no indication on specific wiring types, many of the popular scheme operators do, so the Wiring types referred to in electraform are listed below.


  • A - PVC/PVC cables
  • B - PVC cables in metallic conduit
  • C - PVC cables in non-metallic conduit
  • D - PVC cables in metallic trunking
  • E - PVC cables in non-metallic trunking
  • F - PVC/SWA cables
  • G - XPLE/SWA cables
  • H - MICC (Minerall insulated cables)
  • O - Other types of cables such as SY - YY types