The apparatus used for switching, controlling and protecting the electrical circuits and equipment is known as switchgear. The term ‘switchgear’ is a generic term that includes a wide range of switching devices like circuit breakers, switches, switch fuse units, off-load isolators, HRC fuses, contactors, miniature circuit breakers, ELCBs, GFCIs etc.
Most of the relays used in the power system operate by virtue of the current and/or voltage supplied by current and voltage transformers connected in various combinations to the system
Air blast circuit breaker employs a high-pressure air blast as an arc quenching medium. The construction and working of different types of air blast circuit breakers are explained in this