Lead-sheathed and rubber-insulated cables

Both lead-sheathed and rubber-insulated cables are now very old and well past the normal life expectancy.

During the last few years we have had several fire reports in which the cause of the fire was stated as being due to the failure of lead-sheathed cable. Samples of this cable which have been removed from installations have been examined and in some instances have revealed serious deterioration of the insulating material, to the point where complete failure was imminent. Other samples however, showed little degradation of insulating material. Testing of the cable may not always indicate pending failure and in some instances may actually cause failure of the cable if the degradation of the insulation has reached an advanced state.

Rubber-insulated cables have also been the cause of some concern due to breakdown of the rubber. In some instances the insulation had deteriorated to the extent that all the rubber-insulated cable had to be replaced before power could safely be restored to the premises.

Our policy therefore is to recommend that these types of cable be replaced when any alterations or repairs are being carried out on the electrical installation, in the interests of minimising the risk of shock or fire.

We therefore strongly recommend that customers take every opportunity to upgrade those sections of their electrical installation where lead-sheathed cable or rubber-sheathed cable are installed.