What is a low-voltage switchgear cabinet?

    A low-voltage switchgear cabinet is an electrical device used in the power system to achieve the distribution, 

control, protection, and conversion of low-voltage electrical energy. It is widely applied in scenarios such as 

power plants, industrial workshops, high-rise buildings, and data centers. The following is a collation of its 

core information:

### I. Definition and Functions

- **Definition**:

A low-voltage switchgear cabinet is a complete set of equipment that integrates electrical components such as 

circuit breakers, isolating switches, instrument transformers, and protection devices into a closed or semi-closed 

cabinet body. Through standardized design, it realizes the distribution and control of electrical energy. The rated 

operating voltage is generally 380V or 660V, with a frequency of 50Hz. It complies with national standards such

 as GB7251.1 and needs to pass the 3C certification.

- **Core Functions**:

1. **Electrical Energy Distribution**: Connects the main power supply to multiple branch circuits to supply power 

to different devices.

2. **Motor Control**: Achieves the starting, stopping, and protection (such as overload and short circuit) of the 

motor.

3. **Reactive Power Compensation**: Improves the power factor, reduces line losses, and improves the quality 

of electrical energy.

4. **Safety Protection**: Provides protection against electric leakage, short circuit, overload, etc., isolates the 

fault area, and ensures the safety of personnel and equipment.

### II. Structural Composition

A low-voltage switchgear cabinet is usually composed of the following parts:

1. **Cabinet Body**:

- **Material**: Cold-rolled steel plate or stainless steel, with anti-corrosion treatment on the surface, and the

 protection level can reach above IP30.

- **Compartment Division**:

    - **Busbar Chamber**: Installs the main busbar (horizontal) and branch busbar (vertical), commonly using 

copper busbars, which can carry large currents.

    - **Circuit Breaker Chamber**: Installs circuit breakers and other switching equipment, supporting draw-out

 (removable) or fixed installation.

    - **Cable Chamber**: Connects external cables and is equipped with grounding devices and brackets.

    - **Instrument Chamber**: Installs ammeters, indicator lights, control buttons, etc., for monitoring and 

operation.

2. **Core Components**:

Circuit breakers (air switches), isolating switches, instrument transformers, fuses, contactors, etc.

### III. Classification Methods

#### 1. According to the Structural Form

- **Fixed Switchgear Cabinet**:

The components are fixed in the cabinet body. It has a simple structure and low cost, and is suitable for 

scenarios with stable loads (such as the GGD type).

- **Draw-out Switchgear Cabinet**:

The components are installed in movable drawers or hand carts, with strong interchangeability and easy 

maintenance (such as the GCS, MNS, and GCK types).

#### 2. According to the Connection Method

- **Welded Type**: It has a strong structure, but it is difficult to adjust and is commonly used for non-standard 

customized cabinets.

- **Fastener Connection**: Modular assembly, with high precision and easy to expand (such as the Schneider 

Blokset series).

#### 3. According to the Application Scenarios

- Industrial Type: Adapts to high-temperature and dusty environments, such as the metallurgical and 

chemical industries.

- Civil Type: Used in office buildings and residential buildings, focusing on aesthetics and safety.

- Special Type: Such as explosion-proof cabinets (suitable for flammable and explosive places).

### IV. Typical Models

1. **GGD Type**: It has a fixed structure, low cost, and is suitable for power distribution centers.

2. **GCS/GCK Types**: They are draw-out type, support large currents, and are used for industrial 

automation control.

3. **MNS Type**: It has a modular design, a high protection level, and is suitable for scenarios with 

high reliability requirements such as data centers.

### V. Operating Conditions

- **Ambient Temperature**: -5°C to +40°C, and the average temperature within 24 hours ≤ +35°C.

- **Humidity**: When the maximum temperature is +40°C, the relative humidity ≤ 50%; higher humidity 

is allowed at low temperatures (without condensation).

- **Altitude**: No more than 2000 meters. Special design is required for high altitudes.

- **Pollution Level**: Generally level 3 (slight pollution is allowed).

### VI. Application Scenarios

- **Industrial Field**: Factory power distribution and motor control (such as chemical reactors and metallurgical

 equipment).

- **Construction Field**: Lighting, elevator, and air conditioning power distribution in high-rise buildings.

- **Data Center**: Provides a stable power supply for servers and UPS systems.

- **Energy Industry**: The low-voltage power distribution links of power plants and substations.

### Conclusion

The low-voltage switchgear cabinet is the "hub node" of the power system. Through standardized design

 and modular structure, it realizes the efficient distribution and safe control of electrical energy, and is a 

core device to ensure the stable operation of various power consumption scenarios. When selecting a type, 

it is necessary to comprehensively consider the load characteristics, environmental conditions, and 

maintenance requirements.