Abstract: Improvements to a rating plug for an electronic trip unit of a circuit breaker are disclosed. The rating plug includes a non-volatile memory which has access to current and frame rating information. A microcomputer in the electronic trip unit may receive new current rating information over the World Wide Web from a vendor system to update the current rating information of the rating plug. A program within the circuit breaker may detect errors in the new current rating information and may reject such and revert to a safe mode of operation. A billing system may be connected to the vendor system for calculating charges based on the transmission of the new current rating information. Preferably, the non-volatile memory of the rating plug is programmed at the factory site and a label adhered to the outer case of the rating plug for indicating the current rating.

Abstract: A method and apparatus for rejection of an inappropriate rating plug in an electronic trip unit for a circuit breaker including: a microprocessor programmed to determine an overcurrent condition of the circuit breaker; a nonvolatile memory in operable communication with the microprocessor; the rating plug releasably engaged with the microprocessor, the rating plug includes an identification register; wherein the microprocessor reads the identification register, the identification register includes an identification number; wherein the microprocessor accesses one of a plurality of programs in the nonvolatile memory based on the identification number; and wherein the one of a plurality of programs instructs said microprocessor to perform a validation of said rating plug for operation with said microprocessor.

Abstract: A method and apparatus for rejection of an inappropriate rating plug in an electronic trip unit for a circuit breaker including: a microprocessor programmed to determine an overcurrent condition of the circuit breaker; a nonvolatile memory in operable communication with the microprocessor; the rating plug releasably engaged with the microprocessor, the rating plug includes an identification register; wherein the microprocessor reads the identification register, the identification register includes an identification number; wherein the microprocessor accesses one of a plurality of programs in the nonvolatile memory based on the identification number; and wherein the one of a plurality of programs instructs said microprocessor to perform a validation of said rating plug for operation with said microprocessor.