Abstract: Photoelectric reflective object sensors are mounted in an exteriorly mounted auxiliary switch case to detect a member on a movable contact assembly of the contactor to produce logic level output signals indicative of the operational state of the contactor electromagnet. One or a pair of photoelectric sensors are used in a side mounted auxiliary switch to detect the contactor movable contact assembly in the energized or de-energized position, or en route between the two positions. A single photoelectric sensor is used in a top adder auxiliary switch to detect if the movable contact assembly is or is not in the extended (de-energized) position. The auxiliary switches provided logic level output signals directly usable with microprocessor based controllers.

Abstract: An arc detection method and apparatus is provided for an electric circuit having an electrified conductor (46) connecting a voltage source (26) to a load (30). The arc detector includes a field sensor (62) sensing an electromagnetic field established about the conductor by the occurrence of an electrical arc in the electric circuit, and generating a field responsive signal in response thereto. Arc discrimination circuitry responds to the field sensor and generates an arc indicative signal in response to a random chaotic pattern of the field responsive signal.

Abstract: An arc detection method and apparatus is provided for an electric circuit having an electrified conductor (46) connecting a voltage source (26) to a load (30). A field sensor senses an electromagnetic field established about the conductor by the occurrence of an electrical arc in the circuit, and generates a field responsive signal. Arc discrimination circuitry includes frequency responsive circuitry responding to the field sensor and generating an arc indicative signal in response to a given frequency characteristic of the field responsive signal. The frequency responsive circuitry monitors a plurality of different frequencies of the field responsive signal, and generates the arc indicative signal in response to a given combination of field responsive signal frequencies. A comb filter passes the field responsive signal through a plurality of passbands, and the arc indicative signal is generated in response to a given frequency signature of the field responsive signal.

Abstract: An arc detection method and apparatus is provided for an electric circuit having an electrified conductor (46) connecting a voltage source (26) to a load (30), the conductor having a line side extending from the arc detector to the voltage source, and a load side extending from the arc detector to the load. The arc detector includes a field sensor (62) sensing the electromagnetic field established about the conductor by the occurrence of an electrical arc in the circuit, and generating a field responsive signal in response thereto. Direction sensing circuitry detects whether the arc is from the load side or the line side, and generates a direction indicative signal.