Field Testing of Low-Voltage Power Circuit Breakers

The testing of low-voltage power circuit breakers equipped with series-trip units has long been a neglected activity. Failures of these devices to trip on faults have caused the realization that actual high-current testing is needed. Little attention has been given by users of low-voltage power circuit breakers to these devices other than occasional dressing of contacts and manual tripping and reclosing. Many of those who have concerned themselves with testing have felt that field testing involved procedures and equipment too cumbersome to be practical.