A Guide for the Protection of Wire Line Communications Facilities Serving Electric Power Stations

Some of the wire communications circuits entering electric power stations are used for control and relaying purposes and often are called upon to perform certain operations during periods of power system faults. This constitutes a major problem in the design of the communications system, since power faults usually result in the introduction of extraneous currents and voltages into the commuuications circuit just at the time when the latter is most urgently required to perform its function.