Working principle of Vaccum circuit breaker VCB

The working principle of the VCB vacuum circuit breaker mainly relies on a high vacuum degree to destroy the continuous burning condition of the arc, thus having a strong arc quenching ability. The circuit breaker utilizes a vacuum interruptor chamber containing both fixed and moving contactors, which are enclosed in a vacuum-sealed container. When the circuit breaker is operated, the contacts of the circuit breaker are separated by creating a break between the fixed contactor and the moving contactor, thus achieving the disconnection of the circuit.

The working principle of the vacuum circuit breaker can be subdivided into the following key points:

1, Vacuum insulation characteristics:

vacuum has strong insulation characteristics, because in the high vacuum state, the gas molecules are very thin, the free travel between molecules is relatively large, and the probability of collision is very small. As a result, collision ionization is not the main reason for vacuum gap breakdown, but the metal particle precipitated by the electrode under the action of high strength electric field becomes the main factor causing insulation damage.

2, Formation and extinguishing of arc in vacuum:

The formation and extinguishing process of vacuum arc is different from that of traditional gas arc discharge. In a vacuum, the arc discharge is formed in the metal vapor that evaporates from the contact electrode. According to the different current size, the characteristics of the arc are also different, which can be generally divided into small current vacuum arc and large current vacuum arc. In a small current vacuum arc, when the contact is broken in the vacuum, a cathode spot with strong concentration of current and energy is generated, and a large amount of metal vapor is evaporated from the cathode spot, and the arc is burned in it. When the current crosses zero, the energy of the arc decreases, the temperature of the electrode decreases, the evaporation effect decreases, the particle density in the arc column decreases, and finally the cathode spot disappears and the arc is extinguished.

3, Operating mechanism:

The operating mechanism of the VCB controls the opening and closing of the contactor, which can be spring-operated or electrically driven, depending on the design of the VCB. The operating mechanism drives the mechanical mechanism by driving the cylinder action, so as to realize the closure and disconnection of the dynamic and static contacts.

4, Control Panel:

The control panel provides the necessary electrical and mechanical control buttons to operate the circuit breaker and may include switching coils, relays, and auxiliary switches.

To sum up, VCB vacuum circuit breaker is widely used in power grid because of its small size, light weight and frequent operation, which can realize the circuit opening and closing by using vacuum interrupter and operating mechanism.

The 2 kinds of Vacuum Circuit Breaker Degatech produced:

1, Solid insulated movement type

We have vacuum tube in top side or bottom side as you want. 630A 1250A, 12KV 35KV are avalible.

2, Eco-friendly AIS movement type

We have vacuum tube in top side or bottom side as you want. 630A, 12KV are avalible.