The vacuum interrupter is the most important component of the vacuum circuit breaker. Let's talk about this component:
1. Classification of vacuum interrupters
Generally divided into: Glass vacuum interrupter, Ceramic vacuum interrupter. At present, ceramic vacuum interrupters are commonly used.
2. Materials of vacuum interrupter
①Material of dynamic and static contacts: There are mainly copper-bismuth alloy, copper-chromium alloy, copper-tungsten alloy, etc. At present, copper-chromium alloy is mainly used in vacuum interrupter for circuit breaker.
②The material of the conductive rod: The rods are all made of oxygen-free copper, which is pure copper that does not contain oxygen or any deoxidizer residue. It has no hydrogen embrittlement, high electrical conductivity, good processability and welding performance, corrosion resistance and low temperature performance.
③Material of shielding cylinder: Made of oxygen-free copper, stainless steel, electrical pure iron or copper-chromium alloy and other materials.
④Corrugated pipe material: The corrugated pipe is mainly made of stainless steel with a thickness of 0.1 to 0.2 mm.
3. The life of the vacuum interrupter
The life of vacuum interrupter includes: vacuum life, mechanical life, electrical life
The life of the vacuum interrupter is a vacuum life of 20 years. Because the vacuum degree of the vacuum interrupter is less than 1.33×10-3Pa, the vacuum degree is not always maintained. With the increase of storage time, the vacuum degree inside the arc interrupter will decrease year by year, so the vacuum interrupter is required to be extinguished. If the leakage rate of the arc chamber is less than 1.3×10Pa·L/s, and the arc-extinguishing chamber with an initial vacuum degree of 1.3×10Pa can ensure that its internal vacuum degree is not less than 1.3×10Pa within 20 years.
The mechanical life of the vacuum interrupter is mainly affected by the bellows. The bellows will leak due to material fatigue cracking or wear. Therefore, the mechanical life of the standard vacuum interrupter is generally 6,000 to 20,000 times.
The electrical life of the vacuum interrupter is determined by the number of times of interruption of the rated short-circuit current, or the number of times of interruption of the rated working current. The magnitude of the breaking current is proportional to the wear of the dynamic and static contacts. The greater the breaking current, the greater the wear of the contacts and the shorter the life (the wear of the contacts depends on the material and structure of the contacts).
Jecsany vacuum circuit breakers use high-quality vacuum interrupters to effectively protect lines and equipment from damage due to faults.