Grounding system test apparatus

摘要

The apparatus is used in conjunction with a power center or distribution box of a multi-phase trailing cable resistance grounded power system in coal mines and the like. It provides from phase voltage an adjustable low voltage current source for adjusting the ground fault relay. The voltage is obtained from a phase-controlled triac and is rich in harmonics which makes it useful in locating cable faults in conjunction with any commercially available cable fault detector which operates at power or higher frequency.