Evaluation and Feasibility Study of Isolated Electrical Distribution Systems in Underground Coal Mines.
NTIS: PB/213-741/3 Available for Reference At Bureau Libraries :218 pages
The objectives of the contract were to evaluate the feasibility of isolated electrical distribution systems in underground coal mines and to design, specify, and evaluate such a distribution system. This final report presents a state-of-the-art literature survey on ungrounded and grounded power systems, a report on literature pertaining to human threshold limits of electric shock, an analysis of the performance requirements of isolated systems, and a section on the design and performance specifications for an isolated system. It was established that there is no ideal underground system due to the effect of inherent distributed capacitance to ground which is present in all components of the system. The conclusion is that a completely ungrounded power system of 480 V or more is no safer than any other system from a human shock standpoint; also, the ungrounded system has no advantage with respect to gas ignition hazards. The contractor indicates that the high resistance grounded power system has personnel safety advantages for underground mining application.
CP; Final Contract Report;
NTIS Accession No.
NTIS: PB/213-741/3; Available for Reference At Bureau Libraries
General Electric Corporation