Limitations on the damage mechanism in dry band arcing on all dielectric self supporting cables

A laboratory test has been developed that reproduces the dry band arcing failure mechanism seen under service conditions. The limitations of the test method have been investigated, and a range of test parameters defined within which dry band arcing is the failure mechanism. Comparison with a field trial has shown the similarities between the two, but by using an unrestricted current in the laboratory test, the dry down period is substantially reduced and arcing occurs after every wet/dry cycle. Additionally, the short duration, high current arcs produced add an additional damage mechanism that ensures the laboratory test is considerably more severe than a real installation