How is vacuum circuit breaker working?|News|JGGY Electrical.com

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How is vacuum circuit breaker working?

JGGY vacuum circuit breaker is a circuit breaker that extinguishes arcs in a vacuum medium. The making and closing of the current-carrying contacts and the associated arc interruption takes place in a vacuum chamber in the circuit breaker, called a vacuum interrupter.

What is vacuum circuit breaker?

The vacuum used as arc extinguishing medium in circuit breakers is called vacuum circuit breaker, because vacuum has excellent arc extinguishing performance, so it has high dielectric strength. This is suitable for most standard voltage applications, as for higher voltages vacuum technology was developed but not commercially viable.

The operation of the current-carrying contacts and the associated arc interruption occurs within the circuit breaker's vacuum chamber, known as the vacuum interrupter. The interrupter consists of a steel arc chamber centered on a symmetrically placed ceramic insulator. The vacuum pressure in the vacuum interrupter is maintained at 10–6 bar. The performance of vacuum circuit breakers is mainly determined by the material used for the current-carrying contacts, such as copper/chromium.

How is vacuum circuit breaker working?

The vacuum circuit breaker works on the principle that once the circuit breaker contacts are opened in a vacuum, an arc is created between the contacts by ionization of the metal vapor in the contacts. However, the arc can be easily extinguished because the electrons, ions, and metal vapors generated throughout the arc condense rapidly on the outside of the CB contacts, so the dielectric strength can be quickly restored.

The most important feature of vacuum is that once an arc is generated in a vacuum, the arc can be quickly extinguished due to the rapid increase in the dielectric strength of the vacuum.

In the vacuum circuit breaker, when the contacts are separated due to some abnormal conditions, an arc is generated between the contacts, and the arc is generated by the ionization of metal ions, which depends largely on the contact of the material.

Arc interruption in vacuum interrupters is different from other types of circuit breakers. Separation of the contacts results in the release of the vapour filling the contact spaces. It consists of positive ions released from the contact material. The vapor density depends on the current in the arc. As the current decreases, the rate of vapor release decreases, and after the current is zero, if the vapor density decreases, the medium will regain its dielectric strength.

When the current to be interrupted in the vacuum is very small, the arc has several parallel paths. The total current is divided into many mutually repelling parallel arcs and spreads over the contact surface. This is called a diffusion arc and can be easily interrupted.

At high current values, the arc is concentrated in a small area. It causes rapid evaporation of contact surfaces. Interruption of the arc is possible if the arc remains in a diffused state. If it is quickly removed from the contact surface, the arc will be reignited.

The arc extinguishing of a vacuum circuit breaker is largely influenced by the material and shape of the contacts and the technology that takes into account metal vapors. The path of the arc is constantly moving, so it doesn't get very hot at any point.

After the final arc interruption, the dielectric strength increases rapidly, which is characteristic of vacuum circuit breakers. They are suitable for capacitor switching as it will provide thump-free performance. Small currents are interrupted before the natural current is zero, which can cause chopping, the level of which depends on the contact material.

JGGY Vacuum Circuit Breaker VS1-12 /VS1-24

The JGGY vacuum circuit breaker VS1 12KV 24KV can be used in all typical switching applications such as industrial networks and medium voltage distribution, ranging from short circuit currents and switching loads to busbar sections or connecting networks. Their robust construction including minimal depth and width dimensions will help reduce the need for different panels.

Therefore, these circuit breakers are available with optional earthing switches for plug-in and fixed installations. The main features of this circuit breaker are as follows.