Why is a switchgear called a complete set,and what cabinets does it consist of? - Blog

overview

A switchgear is called a "complete set" because it's not a single device, but rather a complete and coordinated assembly of various electrical equipment, components, connectors, insulation parts, supports, and enclosures.

Main components of switchgear

The term "cabinet" in switchgear cabinet usually refers to a functional unit. A complete substation or distribution room is composed of various cabinets with different functions arranged together. They can be mainly divided into the following categories:

1. Incoming Line Cabinet

Function: The power input to the power system, usually connected to the upstream substation or transformer. It is the "main switch" of the entire system.

KYN61-40.5 switchgear

2. Outgoing Line Cabinet (Feeder Cabinet)

Function: Distributes electrical energy to various downstream power-consuming units (such as transformers in workshops or floors, distribution boxes, etc.).

Main Equipment: Circuit breakers (or load switches + fuse combinations), current transformers, protection devices, etc. A system usually has multiple outgoing line cabinets.

3. Bus Tie Cabinet

Function: Connects two independent busbar sections. When one incoming power line fails, the two busbar sections can be simultaneously powered by another power source through the bus tie cabinet, improving power supply reliability.

Main Equipment: Bus tie circuit breaker and its protection devices.

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4. Metering Cabinet

Function: Specifically used for electricity metering, for power supply departments to settle electricity bills. The cabinet is usually sealed; users must not operate it arbitrarily.

Main Equipment: High-precision voltage transformers, current transformers, and energy meters.

5. PT Cabinet (Voltage Transformer Cabinet)

Function: Provides measurement voltage and protection voltage signals, and provides AC220V power to the operating power supply. Its internal busbars must be protected by high-voltage fuses.

6. Isolation Cabinet

Function: Contains an isolating switch to isolate the busbar or equipment, creating a visible and safe electrical disconnect point for easy maintenance.

Note: Isolating switches do not have arc-extinguishing capabilities; operation under load is strictly prohibited.

7. Capacitor Compensation Cabinet

Function: Used to improve power quality and increase the power factor. It automatically switches power capacitor banks to offset reactive power generated by inductive loads (such as motors).

Main Equipment: Power capacitors, reactors, switching switches (contactors or thyristors), reactive power compensation controller.

other parts

In addition to the common incoming line, metering, PT, and outgoing line cabinets mentioned above, switchgear may also include busbar cabinets, bus tie cabinets, etc. Busbar cabinets are mainly used to connect switchgear in different bays to achieve electrical connection; bus tie cabinets are used to connect different sections of different busbars to ensure electrical continuity between busbars and improve power supply reliability. Furthermore, in some large substations or complex power systems, there may also be switchgear with special functions such as spare bay cabinets and surge arrester cabinets.

KYN28-12 indoor armored metal-enclosed switch equipment

KYN28-12 indoor armored metal-enclosed switch equipment (hereinafter referred to as KYN28-12 switchgear) is suitable for three-phase AC 50HZ, 7.2~17.5kV single busbar and single busbar sectionalized power system, with perfect "five-proof" function. The removable part of the switchgear cabinet can be equipped with extractable vacuum circuit breaker or vacuum contactor, isolation trolley, PT trolley and other components.

KYN28-12 indoor armored metal-enclosed switch equipment