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.
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
The substation earthing system comprises of a grid (earth mat) formed by a horizontal buried conductors. Read about design of substation earthing system here. The grounding system in substation is very