Vulcanised Indian Rubber (VIR)

  • Vulcanised India Rubber insulated cable.
  • Along with imperial T&E, one of the most common historic wiring cables still in use
  • Comes in 2 forms:
    • Twisted pair, cotton/rubber insulated, with no outer sheath
    • singles drawn into conduit
  • Most VIR wiring doesn’t include an earth wire, which is sometimes run as a separate uninsulated single.
  • Rated to 60C
  • Rubber insulation perishes, cracks & falls off
  • Properties with VIR cable are usually in urgent need of rewiring, and may represent a significant safety risk. However some of the Jute / Hessian reinforced rubber cables that are often seen on consumer unit incomers are still often relatively safe.

A good percentage of the remaining old VIR wiring is now in a dangerous condition, especially at termination points. It is common to see insulation that has fallen off, often leaving live & neutral conductors bare, unsupported and in very close proximity. In the worst cases 2 bare conductors can be found twisted round each other with nothing rigid to support them.

The outer insulation has failed on the black sheath of the cable, and in one place the insulation on the inner live wire has also cracked off. This cable is in a very poor state, and is unsafe.

The rule of thumb with old rubber wiring is

  • replace it as soon as possible
  • don’t move it at all, even small movement sometimes causes shorts.

This situation is quite different to early American rubber wiring, which is usually still in sound condition, due to the use of a different rubber formulation. 

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