IEEE C37.27-1987

This guide applies to low-voltage power circuit breakers of the 600 V insulation class with separately mounted current-limiting fuses for use on ac circuits with available short-circuit current of 200,000 A (rms symmetrical) or less. Low-voltage integrally fused power circuit breakers and combinations of fuses and molded-case circuit breakers are not covered by this guide. This guide sets forth recommendations believed essential for the selection of current-limiting fuses (see ANSIC97.1-1972 (R 1978) [3]) for use in combination with low-voltage power circuit breakers, rated in accordance with ANSI/IEEEC37.13-1981 [4].



Revision Standard - Superseded. Low-voltage power circuit breakers of the 600 V insulation class with separately mounted current-limiting fuses, for use on ac circuits with available short-circuit current of 200 000 A (rms symmetrical) or less, are covered. Guidance is provided respecting coordination of circuit breaker and fuse, location of fuses, open fuse trip devices, addition of fuses to existing installations, protection of connected equipment, and tested combinations of circuit breakers and fuses.