Power interrupter device for an electrical distribution system

A power interrupter device for an electrical distribution system comprising a normally opened power contactor in a power line in the device and having a relay, start means connected to said power line and said relay for selectively energizing the coil of the relay to close the power contactor, means for sensing the current flow in the power line after the power contactor is closed to provide a signal proportional to the current flow through the device, means for generating a preset control signal, means for comparing the sense signal to said control signal, means bypassing said start means for maintaining said power contactor in the closed position when the sense signal is at a predetermined reference level with respect to said control signal, a first amplifier connected to said sensing means to amplify the sense signal and having an output, a second high current sense amplifier and a third low current sense amplifier both connected to the output of said first amplifier, a first high current sense comparator connected to said second amplifier and a second low current sense comparator connected to said third amplifier, said control signal generating means supplying a high reference voltage to said first comparator and supplying a low reference voltage to said second comparator, and means connected to the outputs of said first and second comparators for completing a conduction path to said power contactor when the high sense signal level is less than said high reference voltage and when the low sense signal level is greater than the lower reference voltage.