**1. Switchgear Model Identification**
In 1983, the Ministry of Electrical and Mechanical Services introduced a standardized model system for switchgear under the JB/DQ4085 regulation. This framework ensured that all new switchgear products were developed according to uniform specifications, thereby making model management more systematic and efficient.
Switchgear models are generally divided into two categories: product models and full models. The product model is used to identify the type and key features of the equipment, while the full model includes additional details such as specific parameters, environmental conditions, and technical specifications. A typical product model format is as follows:
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Each position in this sequence represents different aspects of the switchgear. For example, in the model XGN2-12(Z):
- **X**: Indicates the type of switchgear (e.g., box-type).
- **G**: Refers to the structural feature (e.g., fixed type).
- **N**: Specifies the installation environment (e.g., indoor).
- **2**: Represents the design series number.
- **12**: Denotes the rated voltage (12 kV).
- **(Z)**: Indicates the type of circuit breaker (e.g., vacuum type).
Common structural indicators include:
- **X**: Box type
- **G**: Fixed type
- **N**: Indoor use
- **Y**: Withdrawable type
- **K**: Armored type
- **J**: Ring network type
**2. Introduction to Switchgear Structure**
There are several common types of vacuum switchgear, each with unique structural features:
1. **Semi-closed fixed vacuum switchgear (GG-1A(F)Z type)**
This model is widely used in power distribution systems due to its simplicity and reliability.
2. **Box-type fixed vacuum switchgear**
- **XGN-10(Z) type**: Features a busbar room with an outgoing conductor connected via a GN30 rotary isolating switch to the vacuum circuit breaker. The lower terminal connects to the current transformer and enters the cable compartment.
- **GGX2-10 (XGN66-10) type**: Utilizes a coaxial rotary multi-channel intermittent transmission mechanism, allowing sequential operation of isolating and grounding switches through a single rotating shaft.
3. **Withdrawable switchgear (JYNâ–¡-10 type)**
This model is divided into four compartments: instrument room, circuit breaker handcart room, busbar room, and cable room. All partitions are typically made of grounded metal plates for safety.
4. **Armored vacuum switchgear (KYNâ–¡-10 type)**
Developed from the interval type, it uses fully grounded metal partitions for enhanced safety. It can be equipped with electromagnetic or spring-operated mechanisms.
5. **Center-mounted armored switchgear**
Designed to reduce the height of the circuit breaker and improve accessibility, this model often uses integral insulating molded parts and high-precision components, resulting in higher costs but better performance.
**3. Selection of Vacuum Switchgear**
When selecting switchgear for substations or power distribution systems, several factors must be considered:
1. **Main Connection Scheme**
Different connection schemes (e.g., cable in/out, overhead in/out, metering, protection) should be chosen based on the specific needs of the system.
2. **Main Bus System**
Options include single bus, single bus with segmentation, and single bus with bypass. Each has its own advantages in terms of cost, reliability, and expandability.
3. **Primary Electrical Components**
The selection of circuit breakers, isolating switches, and current transformers significantly affects the layout and performance of the switchgear. Not all components are compatible with every cabinet type.
4. **Current Specifications**
Some switchgear models support both small and high current ratings, ensuring flexibility in application.
5. **Cabinet Dimensions**
High-current cabinets are usually wider than low-current ones, and side panel thicknesses must be considered when calculating space requirements.
6. **Cable Access**
Cable routing options vary by model, with some allowing front or rear access, and Others requiring specific configurations.
7. **Overhead Line Access**
For overhead lines, a rear cabinet may be required to accommodate wall bushings.
8. **Installation and Layout**
Proper placement of cabinets, especially in large installations, is crucial for maintenance and operational efficiency.
9. **Inter-Cabinet Interlocks**
Functional units that span multiple cabinets require interlocking mechanisms to prevent misoperations. These can be mechanical or electromagnetic, depending on the distance between cabinets.
By carefully considering these factors, users can ensure the safe, efficient, and reliable operation of their electrical systems.
D-SUB Connector
D-SUB Connector
HuiZhou Antenk Electronics Co., LTD , https://www.atkconn.com