Abstract: An improved contactor control system comprising several modules, such as a contactor module, an overload/controller module, a communication module, a bell alarm module, and a power terminal module which are electrically interconnected through a plug-in unit, and mechanically interconnected through one or more snap-in units, and which modules can be interchangeable and arranged relative to the overload/controller module according to a particular industrial application.

Abstract: A circuit controller for selectively connecting a power source to a load includes a switching mechanism, which selectively connects the power source to the load and switches a current which flows through the switching mechanism, and a substantially radiant energy dissipating positive temperature coefficient current limiter for limiting the current which flows through the switching mechanism. The switching mechanism includes a current sensor, which senses the current flowing through the switching mechanism and provides a sensed current value, and a switching controller for disconnecting the power source from the load whenever the sensed current value is above a predetermined current value. The switching mechanism may include a contactor having separable contacts which are responsive to the switching controller. The current limiter may have a first resistance which results from a first series current, and a higher second resistance which results from a second series current.

Abstract: An electrical switching device such as a motor starter is adapted to be controlled through control signals in control wiring and includes separable contacts; an operating mechanism for opening and closing the separable contacts; first terminals for interfacing the control signals to the operating mechanism; a modular surge suppressor circuit for suppressing a surge associated with the control signals, with the modular surge suppressor circuit including second terminals for engaging the first terminals and interfacing the control signals thereto; and a modular terminal block for interfacing the control signals in the control wiring to the modular surge suppressor circuit.

Abstract: An electromagnetic switch includes separable contacts, an electromagnet having a coil which is energized to close and hold closed the separable contacts, a power supply for applying current to the coil, and a closed-loop control circuit for sensing and regulating, throughout a contact closure cycle, the current applied to the coil to a selected current reference. The current reference may include a closing current reference for closing the contacts and a holding current reference for holding the contacts closed.

Abstract: An arc grid plate for an arc box of a contactor includes a conductive plate having two sides, a rear edge, and a front arc edge. The sides are slidable within a pair of grooves of the side walls of the arc box. The rear edge of the conductive plate has two arms which are rearwardly disposed therefrom. Each of the arms has a pointed end for gripping an associated one of the side walls. The pointed ends are generally disengaged from the associated side walls during insertion of the conductive plate into the arc box. The arms are engaged by the rear wall of the arc box and flex forwardly toward the rear edge of the conductive plate in order that the pointed ends of the arms engage the associated side walls and retain the conductive plate within the grooves of the arc box.