A switchgear has protecting and switching devices like fuses, switches, circuit, isolators, protective relays, breakers, lightening arrestors, control panels, current transformers, auto reclosures, potential transformers, and a variety of associated equipment. All that and much more is what the switchgear servicing & maintenance handles.
There is some equipment which is designed to operate under abnormal and normal condition. There are some equipment which is meant for switching and not being able to sense the fault. During the normal operation, the switchgear is able to permit switch off and on generators, distributors, transmission lines and other electrical equipment.
Alternatively, when there is a short circuit or failure which occurs on any part of the power system, there is a high current which flows via the equipment, which threatens damage to the equipment, interrupting service to customers.
But the switchgear tends to detect the fault, disconnecting the section which is unhealthy from the system. At the same time, switching and current device interruption tend to play a big role in the modern network of the electrical, right from the stations which are generating, the transmission substations at various voltages, substations for distribution, and load centers. The device for switching here is referred to as a circuit breaker.