Abstract: A circuit interrupter including an improved arc detection system which trips the interrupter in response to currents having frequencies and/or characteristics associated with arcing within the associated alternating current electrical system. The arc monitoring circuit determines if the signal produced by a current transducer is the result of arcing. The arc detection system includes two swept filters and associated amplifiers which produce a signal which has an amplitude representative of the frequencies present in the alternating current of the electric system. The portion of the filtered signal which has amplitudes above a predetermined level is integrated to produce a trip signal for the circuit interrupter when the value of the integration exceeds a predetermined limit.

Abstract: An overload relay with a multi-function control button is disclosed herein. The overload relay includes a contactor having a solenoid which holds the contacts of the contactor closed when energized. Power to the solenoid is provided by the power conductors connected to the contacts of the contactor. The power provided to the solenoid is controlled by a switch which is operated with the multi-function button. The multi-function button includes a slidable member and an indicator member movably contained within the slidable member. The indicator member is mechanically connected with the contacts of the switch which control the application of power to the solenoid. When these contacts are disengaged, the indicator member has a portion which extends beyond the tubular member to produce a visual indication that the supply of power to the contactor solenoid has terminated and the contacts of the contactor are open.