Plug-in ground fault monitor for a circuit breaker.

摘要

The present invention provides a plug-in ground fault monitor module (16A) for a circuit breaker trip unit (14) configured to operate with a plurality of different plug-in plug-in modules. The ground fault monitor module (16A) includes a memory (36) which stores data representative of the its particular function. This memory (36) is readable by the trip unit (14) and enables the trip unit to automatically adapt to communicate monitored ground fault data to the ground fault module (16A). The ground fault module (16A) also includes means for setting threshold levels (30) for a ground fault alarm signal (714). The ground fault alarm signal (714) is generated independently of ground fault alarms in the trip unit (14) based on its internal thresholds. This signal (714) can be used to control an external relay (604) which operates a shunt trip mechanism (606) or an external alarm (602). The trip unit (14) includes a processor (20) and programming which permits a bi-directional flow of data between the units (14, 16A), such as display data and control data. <IMAGE>