Breakdown features in electric cables with polymeric insulation

Compositions based on polyvinylchloride (PVC), which is sensitive to thermal aging, are used for the majority of electric cables as polymeric insulation. It is shown for the first time by the example of the most widespread polymeric insulation, which is made of polyvinylchloride preliminarily subjected to partial thermolysis, imitating its faster aging, that electrical conductivity of PVC can acquire an anomalous (not following the Ohm law) character due to aging. Transitions of PVC from a state with usual (low) conductivity into a state with anomalously high conductivity that have a spontaneous uncontrollable character are observed in this case. It is especially noteworthy that the character of these variations is large-scale, which makes it possible to easily transform PVC from the state of typical dielectric into the class of conductors. It is noted that the method of removal of a fire hazard (by maximally possible removal of short-circuits caused by thermal aging of polymeric insulation) should have a preventive character, being the most efficient, simplest, and most convenient.