Some high-voltage solid-state soft starters use vacuum contactors or vacuum circuit breakers, which are important primary components of high-voltage solid-state soft starters.
The vacuum circuit breaker has sufficient breaking capacity. When the grid voltage is high and the fault current is large, when the circuit breaker is disconnecting the circuit, it must have a strong arc extinguishing capacity to reliably disconnect the circuit and ensure that it has Adequate thermal and dynamic stability.
So what is the arc extinguishing principle of the vacuum circuit breaker? Vacuum interrupter for circuit breaker. The contact material of copper chrome is selected, and the arc extinguishing chamber has a very high degree of vacuum. When the moving and static contacts are charged and opened under the action of the operating mechanism, a vacuum arc is generated between the contacts to form a magnetic field, so that the arc maintains a diffuse shape, and the arc burns evenly on the contact surface, and maintains a low arc. Voltage.
When the current naturally crosses zero, the residual ions, electrons and metal vapor can gather or recombine on the surface of the contact or the shield in microseconds, the dielectric strength of the fracture of the extinguishing chamber recovers quickly, and the arc is extinguished. To achieve the purpose of breaking.