| 摘要 |
PURPOSE: To provide an overcurrent relay which eliminates an overload by a method wherein, when an apparatus to be protected is set to the overload, a system by a human system is operated before the load is cut off. CONSTITUTION: An overcurrent relay is constituted of a temperature-rise computing means 22 which computes a temperature rise on the basis of a current value and a settling value, of an output judgment means 23 which compares the magnitude relationship between a temperature-rise computed result and the settling value so as to judge a cutoff instruction output, of an allowable-time computing means 2 which comoutes the allowable time up to a cutoff instruction on the basis of the temperature-rise computed result and on the basis of an overload allowable limit temperature at every apparatus to be protected and of a transmission means by which the computed allowable time is transmitted to an overall control place in a power-supply instruction place. |
