Ground fault accessory for a molded case circuit breaker
AssigneeSiemens Aktiengesellschaft
InventorsWilliam E. May, William R. Taylor, Peter N. C. Pang
Life of this patent
Estimating the term…
Abstract
A ground fault accessory for a molded case circuit breaker is provided by converting a shunt trip accessory to automatically trip the breaker when a ground fault occurs. A printed circuit mounted in the housing with the shunt trip eliminates the need for a separate ground fault relay. The ground fault relay and the shunt trip are made available in the same accessory requiring no additional mounting of equipment or external wiring while conserving space which is scarce in load centers and other locations where both ground fault and shunt trip are desired.
Claims12
A ground fault accessory for a circuit breaker for protecting a load circuit, comprising:
- a base having a front portion with an opening;
- a cover having a front portion and being mateable with the base and defining a chamber when mated;
- a terminal strip mounted on the front portions of the base and the cover;
- means for attaching the base and the cover as a unit to the circuit breaker;
- a shunt trip assembly mounted on the base within the chamber and operable to mechanically trip the circuit breaker when actuated;
- and
- a circuit board connected to the base and having a circuit connected to the shunt trip assembly and the terminal strip, said circuit selectively actuating the shunt trip assembly in response to receiving a preselected signal at the terminal strip indicative of a ground fault in the load circuit.
A method for converting a shunt trip accessory for a molded case circuit breaker to a ground fault accessory, comprising the steps of:
- dividing the shunt trip accessory into a base and a cover, said base having a front portion with an opening, said cover having a front portion and being mateable with the base and defining a chamber when mated, said base having a shunt trip assembly mounted thereon within the chamber operable to mechanically trip the circuit breaker when actuated;
- mounting a circuit board on the base, said circuit board having a circuit;
- connecting the shunt trip assembly to the circuit connecting the circuit to a terminal strip mounted on the front portions of the base and cover;
- and
- connecting the base and cover.
Dependencies are inferred from the claim text.