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Portable Calibrator for DC Circuit Breakers.
NTIS: PB 297-732 :43 pages
A portable calibrator to check the trip setting of DC circuit breakers within an accuracy of +/-5 pct was developed for the Bureau of Mines. The calibrator operates from a 300-volt DC trolley wire to provide controlled current pulses of 120 msec duration and continuously adjustable from 1,400 to 3,600 a. These current pulses enable a breaker DC trip current to be determined and subject the contacts to full current rating. The equipment is simple to use and weighs 86 lb. Connections are made with protected, clamp-on leads that are separately connected and weigh about 22 lb. An accurate calibration procedure takes less than 5 min to complete.
CP; Final Contract Report;
NTIS Accession No.
NTIS: PB 297-732
Westinghouse Electric Corp.
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division