LONG DELAY ACCELERATION MODULE FOR AN OVERLOAD RELAY SYSTEM

摘要

A long acceleration module is provided for use with a current sensor which provides an output voltage which varies with load current. There is also provided an inverse time overload logic module which controls the tripping of a circuit breaker to protect the lines in which the load current flows in relationship to the output voltage of the current sensor. The long acceleration module allows motor startup when a motor is connected to the lines to be protected. The long acceleration module purposely simulates a relatively low voltage for the input to the inverse time overload logic module during the motor startup time when high but generally non-dangerous currents are drawn by the accelerating motor.