IEEE C37.04-2018

This standard applies to ac high-voltage circuit breakers with rated nominal voltage above 1000 V. It establishes a rating structure, preferred ratings, construction and functional component requirements. This standard encompasses the following: - Three pole circuit breakers used in three-phase systems - Single pole circuit breakers used in single-phase systems - Attachments for these circuit breakers, such as bushings, current transformers, interlocks, shunt trips, etc., and auxiliary equipment sold with the circuit breakers such as closing relays and structural steel supports. This standard does not cover circuit breakers used at frequencies other than 50 Hz or 60 Hz or generator circuit breakers that are covered in IEC/IEEE Std 62271-37-013