What are the five electrical protections for high-voltage switchgear?

The five prevention lock is a lock installed to achieve the above five prevention measures. To achieve the five prevention functions, it is necessary to cooperate with the microcomputer five prevention system or implement strict personnel five prevention operation rules.

The "Five Electrical Preventions" of High Voltage Switchgear:

The interlocking of high-voltage switchgear is an important measure to ensure the safe operation of the power grid, ensure the safety of equipment and personnel, and prevent misoperation. GB3906-1991 "3-35 kV AC Metal Enclosed Switchgear" has made clear provisions for this. Generally, "interlocking" is described as preventing the accidental opening and closing of circuit breakers; Prevent the opening and closing of isolation switches with load; Prevent live hanging (closing) of grounding wires (grounding switches); Prevent closing with grounding wire (switch); Prevent accidental entry into electrified compartments. The above five measures to prevent electrical misoperation are referred to as the "Five Prevention". The "five prevention" devices are generally divided into three categories: mechanical, electrical, and comprehensive. At present, there are many types of high-voltage switchgear on the market, most of which have interlocking methods with complete shafts.

1. After the vacuum circuit breaker trolley inside the high-voltage switchgear is closed at the test position, the trolley circuit breaker cannot enter the working position. (Prevent closing with load)

2. When the grounding knife inside the high-voltage switchgear is in the closed position, the trolley circuit breaker cannot be closed. (Prevent closing with grounding wire)

3. When the vacuum circuit breaker inside the high-voltage switchgear is closed, the mechanical grounding knife on the back door of the cabinet is used to lock the cabinet door. (Prevent accidental entry into electrified compartments)

4. The vacuum circuit breaker inside the high-voltage switchgear is closed during operation, and the grounding knife cannot be put into operation. (Prevent hanging grounding wires when live)

5. The vacuum circuit breaker inside the high-voltage switchgear cannot exit the working position of the trolley circuit breaker during the closing operation.