A disconnecting switch: in the sub-position, there is an insulation distance between the contacts that meets the requirements of the regulations and an obvious disconnect mark; A switchgear that, when in close position, can carry current under normal loop conditions and current under abnormal conditions (such as short circuit) for a specified period of time. Generally refers to the high voltage isolation switch, that is, the rated voltage in 1kv and above the isolation switch, usually referred to as the isolation switch, is the most used in the high voltage switch electrical appliances, its own working principle and structure is relatively simple, but due to the use of large, high reliability requirements, on the substation, power plant design, establishment and safe operation of the impact are greater. The main feature of the brake is that there is no arc extinguishing ability, and the circuit can only be divided and closed without load current.