Abstract: The invention discloses a vacuum contactor assembly for controlling current flow in a single or multi-phase electrical circuit wherein each phase of the electrical circuit is controlled by a single vacuum interrupter. The stem pressure or pressure exerted on the electrical contacts of each vacuum interrupter during and after closing may be individually adjusted to an optimum operating pressure. The individual interrupter stem pressure adjustment is accomplished by placing a spring and an adjustment nut on the stem screw between the operating arm and the interrupter stem. By adjusting the free length of the spring with the adjusting nut, the interrupter stem pressure may be controlled.

Abstract: The interlocked contactor includes an interlock mechanism which selectively prevents closure of contactor contacts before a preselected number of operations of the contactor. An armature actuator is connected to the armature to cause a slider bar portion of the interlock mechanism to translate between an interlock open and interlock closed position corresponding to the contact open and contact closed positions. The interlock mechanism is generally mounted to a detachable mounting base which is mounted to a contactor frame. The slider bar is positionally maintained before failure of the assembly by a pair of roller carrying studs, one of which is designed to shear before the predetermined number of contactor operations. An arresting base is pivotally mounted for movement about one of the studs providing adjustable alignment with the slider bar. An adjustment shaft determines the degree of clearance between an interlock tab on the arresting base and an arresting notch on the slider bar.