Transistorized, Residual-Current Trip Device for Low-Voltage Circuit Breakers

This paper presents an ultrasensitive trip device applicable to lowvoltage circuit breakers for protection of utilization circuits from high-resistance line-to-ground short circuits. Circuit breakers actuated by milliamperes are believed to be the ultimate protection against ground faults. It is anticipated that the increased protection against electric fires and explosions will be acceptable by industry, in the planning of new homes, and especially welcome to the family having suffered a serious electric shock accident.