what is the difference between switchgear and switchboard
**Switchgear** and **Switchboard** are commonly used terms in electrical engineering, and there are significant
differences between them in terms of function, structure, and application scenarios. The following is a detailed analysis:
I. Core Definitions and Functions
| Term | Definition | Core Functions |
| Switchgear | A set of electrical equipment used for controlling, protecting, and isolating power circuits, usually containing high-voltage or high-current components.。 | 1. Switch the main circuit on and off (such as in power transmission) |
| 2. Provide overload and short-circuit protection | ||
| 3. Isolate faulty circuits (for safe maintenance) | ||
| Switchboard | A panel or cabinet used for distributing low-voltage power and providing control/indication, usually containing low-voltage components. | 1. Distribute the main power supply to multiple branch circuits |
| 2. Monitor electrical parameters (voltage, current) | ||
| 3. Locally control small devices |
II. Voltage Levels and Current Capacities
| Comparison Items | Switchgear | Switchboard |
| Voltage Range | High voltage (above 1kV) or medium voltage (such as 10kV, 35kV) | Low voltage (below 1kV), commonly AC 220V/380V |
| Current Capacity | High current (hundreds to thousands of amperes) | Medium and small current (several to hundreds of amperes) |
| Application Scenarios | Substations, power plants, and main industrial power supply systems | Building power distribution, small industrial equipment, and household distribution boxes |
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III. Structure and Component Composition
**Switchgear**
- **Core Components**:
- Circuit Breaker (CB)
- Disconnector (DS)
- Load Break Switch (LBS)
- Current Transformer (CT), Voltage Transformer (PT)
- **Structural Features**:
- Metal-enclosed cabinets (such as armored type, compartment type), with **high-voltage insulation and arc
extinguishing capabilities**
- Often used in conjunction with protective relays, surge arresters, etc. (in compliance with GB 3906 *AC
Metal-Enclosed Switchgear for 3.6kV～40.5kV*)
**Switchboard**
- **Core Components**:
- Miniature Circuit Breaker (MCB), Residual Current Device (RCD)
- Knife switch, fuse, voltmeter/ammeter
- Control buttons, indicator lights
- **Structural Features**:
- Open or semi-enclosed panels, with **no high-voltage insulation requirements**
- Often integrated with terminal blocks and cable trays (in compliance with GB 7251.3 *Low-Voltage Switchgear
and Controlgear Assemblies*)
IV. Typical Application Scenarios
**Examples of Switchgear**
- **10kV Prefabricated Substation**: High-voltage incoming switchgear (including circuit breakers, surge arresters)
- **Industrial Power Distribution System**: Main circuit switchgear for motor starting/stopping (such as switches supporting
380V frequency converters)
Examples of Switchboard**
- **Household Distribution Box**: Distribute the 220V power supply to lighting, socket, and other circuits
- **Building Floor Power Distribution Room**: Low-voltage switchboards control the lighting and air conditioning systems
V. Standards and Specifications
| Category | Standards for Switchgear | Standards for Switchboard |
| Chinese Standards | GB/T 11022 Common Technical Requirements for Standards of High-Voltage Switchgear and Controlgear | GB 7251.1 Low-Voltage Switchgear and Controlgear Assemblies |
| International Standards | IEC 62271 High-Voltage Switchgear and Controlgear | IEC 61439 Low-Voltage Switchgear and Controlgear Assemblies |
VI. Summary Comparison Table
| Comparison Items | Switchgear | Switchboard |
| Function | Main circuit control and protection | Low-voltage power distribution and local control |
| Voltage | High voltage/Medium voltage | Low voltage |
| Core Components | Circuit breaker, disconnector | Miniature circuit breaker, knife switch |
| Structure | Metal-enclosed cabinet, high-voltage insulation | Panel/cabinet, no high-voltage insulation |
| Standard | GB/T 11022, IEC 62271 GB/T 11022，IEC 62271 | GB 7251.1, IEC 61439 |
**One-Sentence Differentiation**:
**Switchgear** is the "power switching hub" for **high voltage and high current**, used for switching the main
circuit on and off and protection;
**Switchboard** is the "power distribution terminal" for **low voltage and low current**, used for controlling and
monitoring branch circuits.
