Protector apparatus for dynamoelectric machines

摘要

A motor protector having a thermally and electrically conductive housing with a closed end and an opened end and defining a switch cavity therein is hermetically sealed with a header assembly. The header assembly has an outer margin circumscribing a central electrically insulative glass portion through which extends an electrically conductive terminal pin. A thermostatic assembly is mounted on the distal free end portion of the pin within the cavity and includes a heater element which extends from the pin toward the closed end of the housing. A snap-acting thermostatic element is cantilever mounted to the heater intermediate the ends of the heater and has a movable contact disposed on the distal free end thereof. A stationary contact is disposed within the cavity and is physically and electrically connected to the housing adjacent the closed end thereof on a relatively flat shelf formed in the wall of the housing. The movable contact is adapted to move into and out of engagement with the stationary contact upon the occurrence of preselected temperature conditions of the thermostatic element. The housing is configured to provide rotational orientation to facilitate assembly thereof and in addition so that it can be inserted into a pocket formed in the windings of a dynamoelectric machine of various ratings or placed on the outer peripheral portion of the windings in close thermal contact therewith.