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Sensitive Ground-fault Protection for Mines. Phase II--direct- current Utilization.
Kohler-JL; Trutt-FC; Morley-LA
NTIS: PB 87-203410 :81 pages
This report for Phase II of Bureau of Mines contract jo134025 describes the research and development of sensitive ground-fault relays for direct current utilization systems in mining. Sensitive relaying employs very low pickup levels so that, when used in conjunction with very high resistance grounding, the exposure of a human to ventricular fibrillation is significantly reduced. To delineate the desired relay characteristics, the report begins by reviewing previous research in this area, and a theory for the saturable transformer used to sense the fault current is presented. The design of the ground-fault relay is described in sufficient detail so that it may be duplicated, and the test procedures and results are given.
CP; Final Contract Report;
NTIS Accession No.
NTIS: PB 87-203410
Pennsylvania State Univ.
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division