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Sensitive Ground-fault Protection for Mines. Phase I. Alternating- current Utilization.
Morley-LA; Trutt-FC; Novak-T
NTIS: PB/85-185767 :90 pages
This report covers research and development of ground-fault relays for use on low-voltage alternating-current utilization circuits in mining. Sensitive relaying employs very low pickup levels such 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 reviews and updates previous research in this area. The critical relay component for sensitive ground-fault relays has been found to be the current transformer. Electronics for two prototype relays-- an analog relay and a digital relay--have been produced through the research, and information is presented so that either may be duplicated.
CP; Final Contract Report;
NTIS Accession No.
Penn State Univ.
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division