Abstract: A method of determining contact wear in a trip unit of a circuit breaker and a circuit breaker employing such a method are presented. The trip unit includes a microcontroller and associated memories. An algorithm (program) stored in a memory of the trip unit calculates cumulative energy dissipated in the breaker contacts using the current signal detected at the time of separation. Measurement of cumulative energy dissipated in the breaker contacts is proportional to contact wear. Maintenance setpoints are determined based on industry standard endurance tests and alarm threshold and trip thresholds further based on industry standards are provided within the algorithm for notifying local or remote personnel of a necessary maintenance procedure.

Abstract: A method of event analysis in an intelligent electronic device is presented. The intelligent electronic device includes a microprocessor and associated memories. An algorithm (program) stored in a memory of the intelligent electronic device analyzes events of an electrical distribution system at the intelligent electronic device.

Abstract: A method of detecting systemic fault conditions in an intelligent electronic device is presented. The intelligent electronic device includes a microcontroller and associated memories. An algorithm (program) stored in a memory of the intelligent electronic device detects systemic fault conditions, i.e., root causes, as indicated by repeated, similar fault events.

Abstract: A method of statistical analysis in an intelligent electronic device for data reduction and analysis is presented. The intelligent electronic device includes a microcontrol and associated memories. An algorithm (program) stored in memory of the intelligent electronic device processes real time data on measured and/or calculated electrical parameters using recognized statistical and/or numerical techniques. The algorithm will issue events and/or alarms when observed data is recognized to deviate in statistically significant amounts from statistical values. Allowing only valuable user information, as opposed to “raw” unprocessed and potentially insignificant data, to be sent across a limited capacity network for potential user intervention. Thereby saving network capacity and ensuring that a user is automatically notified of significant events requiring further analysis and/or intervention.

Abstract: A method of determining contact wear in a trip unit of a circuit breaker is presented. The trip unit includes a microcontroller and associated memories. An algorithm (program) stored in a memory of the trip unit measures temperatures relative to circuit breaker contacts and cumulative energy dissipated in the breaker contacts, and utilizes them in a variety of analysis techniques within the trip unit to determine contact wear. These techniques include, by way of example, differential temperature analysis, measurement of cumulative energy dissipated in the breaker contacts, and calculated contact wear using sampled electrical currents and voltage and Ohm's law.

Abstract: A method of determining contact wear in a trip unit of a circuit breaker and a circuit breaker employing such a method are presented. The trip unit includes a microcontroller and associated memories. An algorithm (program) stored in a memory of the trip unit calculates cumulative energy dissipated in the breaker contacts using the current signal detected at the time of separation. Measurement of cumulative energy dissipated in the breaker contacts is proportional to contact wear. Maintenance setpoints are determined based on industry standard endurance tests and alarm threshold and trip thresholds further based on industry standards are provided within the algorithm for notifying local or remote personnel of a necessary maintenance procedure.

Abstract: A method of detecting manual trips and reclose operations in an intelligent electronic device, e.g., electronic trip unit or protective relay, is presented. The intelligent electronic device includes a microcontroller and associated memories. An algorithm (program) stored in a memory of the intelligent electronic device detects manual trips when the following conditions are satisfied: (1) no trip event message has been issued by the trip unit within the reaction time required to trip the circuit breaker; (2) current becomes zero on all phases of the line; and (3) voltage downstream from the circuit breaker becomes zero on all phases. Reclose operations are detected when load side voltages on all phases return from 0V to nominal levels of the line side of the breaker.

Abstract: A method of determining contact wear in a trip unit of a circuit breaker is presented. The trip unit includes a microcontroller and associated memories. An algorithm (program) stored in a memory of the trip unit measures temperatures relative to circuit breaker contacts and cumulative energy dissipated in the breaker contacts, and utilizes them in a variety of analysis techniques within the trip unit to determine contact wear. These techniques include, by way of example, differential temperature analysis, measurement of cumulative energy dissipated in the breaker contacts, and calculated contact wear using sampled electrical currents and voltage and Ohm's law.

Abstract: A method of determining contact wear in a trip unit of a circuit breaker is presented. The trip unit includes a microcontroller and associated memories. An algorithm (program) stored in a memory of the trip unit measures temperatures relative to circuit breaker contacts and cumulative energy dissipated in the breaker contacts, and utilizes them in a variety of analysis techniques within the trip unit to determine contact wear. These techniques include, by way of example, differential temperature analysis, measurement of cumulative energy dissipated in the breaker contacts, and calculated contact wear using sampled electrical currents and voltage and Ohm's law.

Abstract: A method of predicting an eminent circuit breaker trip condition using an intelligent electronic device such as a trip unit, a protective relay, a power meter or other IED is presented. The intelligent electronic device includes a microcontroller and associated memories. An algorithm (program) stored in a memory of the intelligent electronic device generates a near-trip event for each trip event calculation if preset thresholds for the measured parameters are breached.