Cable testing and cable fault locating with minimum risk to good cable

Abstract

It is noted that the introduction of cables with solid dielectric insulation and of modern splicing technology has imposed new standards and restrictions on cable testing and cable fault locating. The arbitrary use of high voltages and energies during DC, AC, and impulse testing of in-service power cables with solid dielectric insulation frequently programs the cables with defects which become faults after the cables are returned to service. The inadequacy of DC testing in determining the cables' AC breakdown strength, the danger of programming the cables with faults when DC and impulse testing at unnecessarily high voltages, and the advantages of very low frequency (VLF) testing and arc reflection methods (ARM) in locating cable defects and faults are presented. It is concluded that by establishing cable fault locating and cable testing guidelines for cable with solid dielectric insulation, which incorporate current research and available technology, utilities can realize substantial savings in cable replacement, cable rehabilitation, and work force budgets. >