Title :
Measuring molded case circuit breaker resistance
Author :
Shea, John J. ; Bindas, John A.
Author_Institution :
Westinghouse Sci. & Technol. Center, Pittsburgh, PA, USA
Abstract :
Molded case circuit breaker resistance is measured under various conditions to demonstrate the need for more standardized procedures when performing millivolt drop measurements. Breakers, rated at 600 V/sub ac//250 A/sub ac/ and 120/240 V/sub ac//50 A/sub ac/, with silver-tungsten (Ag-W) contacts are used to show that contact resistance can cause variability in circuit breaker resistance and to demonstrate the influence of current, time, contact temperature, and applied voltage on contact resistance. Based on these results, guidelines are developed for making reliable resistance measurements on molded-case circuit breakers (MCCB) when using the millivolt drop technique.<>
Keywords :
circuit breakers; contact resistance; electric resistance measurement; electrical contacts; 120 V; 240 V; 250 A; 50 A; 600 V; Ag-W contacts; MCCB; contact resistance; contact temperature; current effect; millivolt drop measurements; molded case circuit breaker resistance; resistance measurements; time effect; Circuit breakers; Circuit testing; Computer aided software engineering; Contact resistance; Current measurement; Electrical resistance measurement; Guidelines; Performance evaluation; Temperature; Voltage measurement;
Conference_Titel :
Electrical Contacts, 1992., Proceedings of the Thirty-Eighth IEEE Holm Conference on
Conference_Location :
Philadelphia, PA, USA
Print_ISBN :
0-7803-0576-0
DOI :
10.1109/HOLM.1992.246920
