What is a high-voltage switchgear

1、 Material of high-voltage switchgear cabinet body

1. Cold rolled steel plate or angle steel (used for welding cabinets);

2. Aluminum zinc coated steel plate or galvanized steel plate (used for assembling cabinets)

3. Stainless steel plate (non magnetic)

4. Aluminum plate (non magnetic)

2、 Functional units of high-voltage switchgear:

1. Main busbar room (generally arranged in two structures: "pin" or "1")

2. Circuit breaker room

3. Cable room

4. Relay and instrument room

5. Cabinet top small busbar room

6. Secondary terminal compartment

3、 Functions of the switchgear

The switchgear has functions such as overhead incoming and outgoing lines, cable incoming and outgoing lines, and busbar connection.

4、 Composition of switchgear

The switchgear should meet the relevant requirements of GB3906-1991 "3-35 kV AC Metal Enclosed Switchgear" standard, consisting of two parts: the cabinet body and circuit breaker. The cabinet body is composed of a shell, electrical components (including insulation parts), various mechanisms, secondary terminals, and wiring.

5、 Classification

According to the installation method of circuit breakers

According to the installation method of circuit breakers, they are divided into movable (handcart) and fixed types

1. Mobile or handcart (represented by Y): indicates that the main electrical components inside the cabinet (such as circuit breakers) are installed on withdrawable handcart. Due to the good interchangeability of handcart cabinets, it can greatly improve the reliability of power supply. Commonly used handcart types include isolation handcart, metering handcart, circuit breaker handcart, PT handcart, capacitor handcart, and used variable handcart.

2. Fixed type (represented by G): indicates that all electrical components inside the cabinet (such as circuit breakers or load switches) are installed in a fixed type, and fixed switch cabinets are relatively simple and economical.

By installation location

Divided into indoor and outdoor according to installation location

(1) For indoor use (represented by N): indicates that it can only be installed and used indoors;

(2) For outdoor use (indicated by W): indicates that it can be installed and used outdoors.

6、 According to the cabinet structure

According to the cabinet structure, it can be divided into four categories: metal enclosed armored switchgear, metal enclosed interval switchgear, metal enclosed box switchgear, and open switchgear

(1) The main components of metal enclosed armored switchgear (represented by the letter K), such as circuit breakers, transformers, busbars, etc., are respectively installed in grounded metal partition compartments.

(2) Metal enclosed bay switchgear (represented by the letter J) is similar to armored metal enclosed switchgear in that its main electrical components are also installed in separate compartments, but have one or more non-metallic partitions that meet a certain level of protection.

(3) Metal enclosed box type switchgear (represented by the letter X) The switchgear enclosure is a metal enclosed switchgear.

(4) Open type switchgear, without protection level requirements, with some parts of the casing being open switchgear.

7、 Five prevention measures for high-voltage switchgear

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

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

3. When the vacuum circuit breaker inside the high-voltage switchgear is closed, the back door of the panel and cabinet is locked with a mechanical device on the grounding knife. (To prevent accidental entry into live compartments)

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

5. The vacuum circuit breaker inside the high-voltage switchgear cannot exit the working position of the trolley circuit breaker when it is working and closing. (To prevent loaded knife brakes)

KYN61-40.5 HV SWITCHGEAR