Low temperature ambient effect for outdoor vacuum circuit breaker (VCB) operation

The vacuum arc - interrupting performance relies on the arcing within the metal vapor, which is generated from the contact material. Significantly, this process remains unaffected by low temperatures.

A vacuum interrupter is typically fabricated from metals and ceramics and undergoes brazing at approximately 800 degrees Celsius. The material characteristics of both metal and ceramic, as well as the brazed joints between them, are inherently resistant to low - temperature impacts.
Sliding guides are employed to direct the moving electrode assembly of the vacuum interrupter (VI). Metal - based guides are impervious to low temperatures, while plastic - made guides can withstand the required low - temperature conditions.

Vacuum circuit breaker (VCB) mechanisms are low - energy systems, traditionally composed of springs and linkages. Through proper design, these components can be engineered to be immune to low - temperature effects. In more recent mechanism designs that utilize the stored magnetic energy from permanent magnets, material selections are made such that the components can tolerate the necessary low temperatures. Additionally, the installation of heaters can further enhance the operational performance of these mechanisms.

In conclusion, a vacuum circuit breaker can be specifically designed to function effectively at low temperatures ranging from - 30°C to - 50°C. The accompanying photo depicts a 36 kV VCB situated within a test chamber for conducting both low - and high - temperature tests.