1- How to Select a Vacuum Circuit Breaker VCB
Here are some basic points to help VCB engineer purchasers to select their VCB products efficiently and professionally.
A. Fill Right Technical Specification Data
-Rated voltage
-Rated current
-Rated breaking current
-Rated short circuit breaking current
-Rated short circuit making current(peak)
-Rated duration of short circuit
-Rated operating sequency
-The rated motor energy storage voltage
-Rated closing voltage
-Rated opening voltage
-Rated Insulation Level ：Rated power frequency withstand voltage /1min and Rated lightning impulse withstand voltage : must meet the requirements of standards such as GB/T 11022 and be compatible with the system insulation.
B. Do you have a requirements on VCB's Service Life?
-Service Life: The mechanical life of low voltage and medium voltage vcb generally requires 10,000 to 20,000 cyles, XDTZ manufactured high voltage vcb service life could be higher to 30,000 cycles.
-Rated operating sequence: Commonly: O-0.3s-CO-180s-CO.
-Opening/closing time and opening/closing speed: These are important mechanical tenical datas that ensure the circuit breaker's interrupting performance.
D. Operating Mechanism Type: Spring mechanism or Permanent magnet mechanism?
Do you know the differences between Spring mechanism and Permanent magnet mechanism?
The spring mechanism is totally mechanical, no need to charge and the service life could be shorter than permannet magnet mechanism.
Then the permannet magnet mechanism need charge and have a longer service compared with spring operating.
E.There are also other important considerations , such as applying ambient conditions:
- Temperature
- The height above the sea level
- Relative humidity
- Saturated vapor
- Earthquake intensity
Here are 10Kv and 24 kV VCB Selection Tables from XDTZ:
10kV VCB Selection Table
24kV VCB Selection Table
2-How to Choose a Switchgear :
Switchgear is a complete set of equipment that integrates circuit breakers, disconnectors, instrument transformers, protective devices, and more.
Followings are some basic principles help you selcet a switchgear
A. Type Selection
Select by main wiring diagram / structure / insulation medium
B. Technical Parameters
Rated parameters, internal arc classification (IAC), degree of protection (IP code), creepage distance, and air insulation distance.
C. Outer and Environmental Requirements
Dimensions and layout, pressure relief ducts, and environmental conditions: altitude, ambient temperature, humidity, pollution level, etc.
Here is a reference of DXG-12 selection from XDTZ:
Shaanxi West Power Tongzhong Electrical Co., Ltd.
Contact: Ms.Melody (Director of Sales Department)
Tel : +86 18091765658(WhatsApp/Wechat/skype )
