Patent ID: 7830231

Claim:
An electrical switching apparatus comprising: separable contacts; an operating mechanism structured to open and close said separable contacts; and a trip unit cooperating with said operating mechanism to trip open said separable contacts, said trip unit comprising: a sensor structured to sense current flowing through said separable contacts, a processor structured to output a trip signal responsive to said sensed current, and a trip actuator comprising: a housing including a recess, a coil within the recess of the housing, the coil having an opening therethrough, a magnet within the recess of the housing, a thermoplastic bushing including a conduit therethrough, the thermoplastic bushing being coupled to the housing, and an armature disposable within the opening of the coil and slidably disposed within the conduit of the thermoplastic bushing, the magnet attracting the armature toward said housing; and a spring biasing the armature away from said housing, in order to cause said operating mechanism to trip open said separable contacts, wherein said housing further includes a cover having an opening therein, wherein the armature includes a first end structured to pass through the opening of the cover and a second end opposite the first end, the second end including an opening therein, said spring engaging the armature within the opening of the second end thereof, and wherein the armature slidably engages the thermoplastic bushing at said conduit.