Vacuum Circuit Breaker. Its advantages, disadvantages and applications.

Table of Contents.

1. What is Vacuum circuit breaker?

2. Advantages of Vacuum circuit breaker.

3. Disadvantages of Vacuum circuit breaker.

4. Application of Vacuum circuit breaker.

What is vacuum circuit breaker?

    The arc extinguishing medium is the vacuum. The vacuum has much better arc quenching capabilities than any other medium since it has the highest insulating strength.

    For example, when the contacts of a circuit breaker are opened in vacuum, the current interruption occurs at the first current zero and the rate of the dielectric strength building up between the contacts is thousands of times faster than with other circuit breakers.

Advantages of vacuum circuit breaker.

Advantages:

➥ The vacuum circuit breaker does not require filling of oil or gas. They do not need auxiliary air system, oil handling system etc. So no need of periodic refilling.

➥ They are compact, reliable and have longer life.

➥ Since there is no oxygen in the arcing region, there are no fire hazards.

➥ During and after the operation, no gas is produced.

➥ Any fault current can be interrupted by this type breaker.

➥ They operate relatively quietly and need little maintenance.

➥ They have low arc energy.

➥ Since they have little inertia, the control system just needs a little power.

➥ Constant contact resistance. In vacuum the contacts cannot oxidize. Therefore, their very small resistance is maintained throughout their life.

Disadvantages of vacuum circuit breaker.

Disadvantages.

➥ It requires high technology for production of vacuum interrupter.

➥ The interrupter is considered completely useless and unable to be fixed on site if there is a vacuum loss as a result of transit damage or failure.

➥ It needs additional surge suppressors in parallel with each phase for interruption of low magnetizing current in a certain range. 

Related Post: Construction and working of vacuum circuit breaker.

Application of vacuum circuit breaker.

Application:

➥ Vacuum circuit breakers are typically used in medium voltage applications.

➥ These breakers have definite superiority over the oil or air circuit breakers. Where the voltages are high and current to be interrupted is low.

➥ This breaker can be employed for capacitor switching which is very difficult for oil circuit breakers.

➥ Because of least requirements of maintenance these breakers are very suitable for a majority of applications in remote rural areas.

Read more:

1. Air-blast circuit breaker advantages, disadvantages and its application

2. Oil Circuit Breaker with advantages, disadvantages and its application

3. Sulphur hexafluoride(SF6) Circuit Breaker advantages and disadvantages.