Abstract: An electronic trip unit for a circuit breaker includes a programmed microprocessor and a module plug in removable signal communication with the microprocessor. The module plug includes a program identifier. The microprocessor recognizes the program identifier and accesses a program of a plurality of programs external to the module plug based on the program identifier. The microprocessor responds to the program to perform a function identified by the module plug. The function identifiable by the module plug includes a communications function, a load monitoring function, a non-tripping ground fault alarm function, a flag function, or any combination thereof.

Abstract: An electronic trip unit for a circuit breaker includes a programmed microprocessor and a module plug in removable signal communication with the microprocessor. The module plug includes a program identifier. The microprocessor recognizes the program identifier and accesses a program of a plurality of programs external to the module plug based on the program identifier. The microprocessor responds to the program to perform a function identified by the module plug. The function identifiable by the module plug includes a communications function, a load monitoring function, a non-tripping ground fault alarm function, a flag function, or any combination thereof.

Abstract: An electronic trip unit for a circuit breaker includes: a microprocessor, the microprocessor programmed to determine an overcurrent condition of the circuit breaker; a nonvolatile memory in electronic communication with the microprocessor; a module plug releasably engaged with the microprocessor, the module plug includes an identification register; wherein the microprocessor reads the identification register, the identification register including an identification number; wherein the microprocessor accesses one of a plurality of programs in the nonvolatile memory based the identification number; and wherein the one of a plurality of programs instructs the microprocessor to perform steps necessary to operate one or more functions of the module plug.

Abstract: An electronic trip unit for a circuit breaker includes: a microprocessor, the microprocessor programmed to determine an overcurrent condition of the circuit breaker; a nonvolatile memory in electronic communication with the microprocessor; a module plug releasably engaged with the microprocessor, the module plug includes an identification register; wherein the microprocessor reads the identification register, the identification register including an identification number; wherein the microprocessor accesses one of a plurality of programs in the nonvolatile memory based the identification number; and wherein the one of a plurality of programs instructs the microprocessor to perform steps necessary to operate one or more functions of the module plug.

Abstract: A molded plastic rating plug enclosure houses the molded case circuit breaker rating plug printed circuit board. The rating plug enclosure is inserted within the circuit breaker cover and is adapted for removal from the circuit breaker cover by means of a special extractor tool. Access means for connecting a test jack with the circuit breaker trip unit printed circuit board and visual access means for an indicating diode are formed within the cover of the rating plug enclosure.

Abstract: A sensing current transformer having a single turn primary winding for ground fault circuit interrupters and breakers utilizes a conductive post extending through the transformer metallic enclosure in combination with the conductive path across the metallic closure as the current sensing path. A four turn primary winding is provided by four metallic staples, each having one leg extending through the transformer aperture, for establishing four independent current sensing paths.