Cable system neutral grounding impedance

Determination of the permissible neutral resistance or reactance for the grounding of cable systems for 3 phase power supply is considered in this paper. The theory of overvoltages which may arise as a result of intermittent arcs to ground through a cumulative action is discussed, and a description of the method for calculating these voltages is given. A simplified criterion for determining the value of neutral resistance or neutral reactance for limiting the over-voltages is proposed which permits the use of higher values than any preceding method.