Abstract: A field configurable contactor is disclosed. The contactor preferably includes a plurality of spaces adapted to receive any number, up to its limit, of contact modules. Each contact module preferably includes a pair of contacts and a spring biased cam follower which opens and closes the contact pair when a cam profile of the contactor moves according to energization or de-energization of the contactor. The contact module can be either “normally open” or “normally closed” depending on its initial placement onto the contactor relative to the cam profile. A latch assembly in the contactor may hold the contactor mechanically during de-energization.

Abstract: A combination circuit breaker/motor starter includes a circuit breaker trip unit having a microprocessor and at least one removably connectable contactor or other functional module. The functional module is encoded with an identifier, such that the microprocessor can determine the type of functional module and appropriate configuration parameters, such as trip times, for the particular application of the functional module. Power is supplied continuously to the trip unit during motor overload or short circuit conditions.

Abstract: A motor control compartment provides an air flow chamber at the rear thereof and mounts the solid state switches on heat sinks that are positioned in the air flow. An apertured support plate separates the interior of the compartment from the air flow chamber and allows additional space for supplemental control equipment.

Abstract: A motor controller unit includes an operating program that controllably responds to manual motor start and stop commands for protection of the semiconductor switches connected with each phase of a multi-phase electric motor. Upon receipt of a start command, a determination is made as to whether the measured time lapse between a previous stop command is less than a predetermnined time delay period.