Title:
A METHOD OF DETERMINING CONTACT WEAR IN A TRIP UNIT
Document Type and Number:
WIPO Patent Application WO2000039823
Kind Code:
A9
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.
Inventors:
ANDERSEN BO L
Application Number:
PCT/US1999/031083
Publication Date:
August 22, 2002
Filing Date:
December 28, 1999
Export Citation:
Assignee:
GEN ELECTRIC (US)
International Classes:
H01H1/00; G01N25/18; H01H9/54; H01H47/00; (IPC1-7): H01H1/00
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