The power system which deals up to 1KV is called as LV or low voltage switchgear. This kind of equipment mainly includes switches, LV circuit breakers, HRC fuses, earth leakage (EL) circuit breakers, offload electrical isolators, MCBs (miniature circuit breakers) and MCCBs (molded case circuit breakers), etc.

The power system which deals up to 36 kV is called MV (medium voltage switchgear). These are available in different types like without metal enclosure outdoor type, metal-enclosed indoor & outdoor type, etc. This kind of equipment includes substation devices like minimum oil CBs, bulk oil CBs, SF6 gas-insulated, air magnetic, gas-insulated, vacuum, etc.

The disruption medium of this type of switchgear can be vacuum, SF & oil. The main condition of this type of power network is to break off current throughout faulty conditions in this system. This is capable of ON/OFF operation, interruption of short circuit current, capacitive current switching, inductive current switching and used in some special applications.

The power system which deals above 36KV is called HV (high voltage) switchgear. When the level of voltage increases then the arcing will be generated as the switching operation is extremely high. As a result, during the designing of this equipment, special care has to be taken. The main component of this equipment is the High Voltage (HV) circuit breaker.

Therefore HV circuit breaker must include some safe & reliable operation features. The switching operation of the HV circuit is very rare. Usually, these CBs remain at ON state and can be worked after some time. Consequently, these must be reliable to make certain secure operations when required.