Abstract: The contact fingers of electrical switching apparatus have radial convex surfaces centered on the pivot pins which seat on concave surfaces in the molded contact carrier to transmit bending loads on the pin into the carrier. A seal member which snaps onto the end of the pivot pin has fins which extend between the contact fingers to block flow of arcing gases through the carrier. For lower current ratings, some of the contact fingers are replaced by annular spacers which also transmit bending moments into the carrier and restrict gas flow. A stop ledge on the carrier against which the contact springs bias the contact fingers has a recess which allows the center fingers to project farther toward the stationary contacts so that the arc toes on these fingers are the last to separate on opening and the arc is concentrated on them.

Abstract: A molded case circuit breaker is provided with ground fault protection by a modular unit which drops into a pole compartment in the molded casing in place of a pole assembly. The modular unit includes a housing forming an open faced cavity across which is mounted a printed circuit board with the ground fault circuit components and trip solenoid projecting into the cavity. The housing also supports the ground fault sensing toroid in a position for the appropriate conductors to pass through the coil. A bell switch and auxiliary switch are positioned by the housing for actuation by levers mounted on the cradle pin and crossbar, respectively. An integral leaf spring molded into the housing accommodates for manufacturing tolerances and fixes the positions of the various components.