Siemens Energy & Automation, Inc.

Mikhail Golod

Mario Bilac

Paul J Terricciano

Charles Randall Dollar, Ii

Chun Fan

Euclid Batista

William Petrosky

A system, method, and device for protecting an induction motor are disclosed. The exemplary system may have a module for determining the current drawn by the motor and a module for determining the state of the motor. The system may calculate a used thermal capacity based on a first formula when the motor is in an active state. The system also calculates the used thermal capacity based on a second formula when the motor is in an inactive state. When the used thermal capacity attains a threshold, the relay is tripped thus removing current to the motor and preventing motor from overheating. A method to derive thermal time constants from desired trip time limits (such as those defined by IEC standards or the thermal limit curves provided by motor manufacturers) is also presented. For example, the thermal time constants can then be used in tacking motor used thermal capacity throughout various motor states.

System, device, and method for over-current relays protecting motors

A circuit breaker system (FIG. ) using electronic trip units is disclosed. The electronic trip units are coupled to a communications bus whereby the electronic trip units can be reconfigured, controlled, and/or monitored by a central computer Further, the electronic trip units are coupled to a separate control power supply line and to a zone selective interlock system.

Circuit breaker communication and control system

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Alpharetta, GA, United States of America

Mikhail Golod