What does a vacuum circuit breaker do?

Protects the use of high-voltage electrical equipment such as large-scale silicon rectifier devices.

What are the features of vacuum circuit breakers?

Strong arc extinguishing ability, short arc burning time, and short full breaking time.

The electrical wear of the contact is small, the electrical life is long, and the contact is not eroded by harmful gases from the outside.

The contact opening distance is small, which reduces the operating power of the operating mechanism and has a long mechanical life.

The structure is simple, the maintenance workload is small, and the vacuum arc extinguishing and contact do not need to be overhauled.

Small size and light weight.

The environment is less polluted.

It is suitable for frequent operation and fast cut-off, especially for cut-off of capacitive load circuits.

Circuit breaker function: The circuit breaker can be used to turn on and off the circuit under normal conditions, and can be used to cut off the short-circuit fault current, so it undertakes the dual task of control and protection at the same time.

Classification of circuit breakers: circuit breakers are divided into oil circuit breakers, sulfur hexafluoride circuit breakers, vacuum circuit breakers, compressed air circuit breakers, magnetic blowing circuit breakers, etc. according to the arc extinguishing medium used.

The main function of the vacuum circuit breaker is to break and turn on the circuit (including breaking and turning on the normal current and breaking the short-circuit current).

The absence of a conductive medium in the vacuum causes the arc to extinguish quickly, so the spacing between the static and dynamic contacts of this circuit breaker is small.

Under normal working conditions, the circuit breaker is closed (except for special applications) and the circuit is turned on. When the automatic control or protection control operation is carried out, the circuit breaker can be used to break or turn on the circuit under the control of the comprehensive protection device.

The circuit breaker can not only turn on and off the normal load current, but also withstand the short-circuit current for a certain period of time (several times or even dozens of times the normal working current), and can cut off the short-circuit current and cut off the faulty lines and equipment.

The circuit breaker has the function of overload, short circuit and undervoltage protection, and has the ability to protect the line and power supply.

The vacuum circuit breaker is named because the arc extinguishing medium and the insulating medium in the contact gap after arc extinguishing are high vacuum; It has the advantages of small size, light weight, suitable for frequent operation, and no need for maintenance for arc extinguishing, and is widely used in the distribution network.

The working principle of the vacuum circuit breaker is: when the dynamic and static contacts are opened under the action of the operating mechanism, the arc is generated between the contacts, and the surface of the contact volatilizes steam at high temperature, because the contact is designed to be a special shape, a magnetic field is generated when the current passes, and the arc moves rapidly along the tangential direction of the contact surface under the action of this magnetic field, and condenses part of the metal vapor on the metal cylinder (shielding cover), and the arc is extinguished when it naturally crosses zero, and the medium strength between the contacts is quickly restored.

Almost everyone has seen a circuit breaker in their home or office. Almost everyone knows how important they are to prevent overloads, ground faults, and short circuits. But not everyone can tell if it's a vacuum circuit breaker or an air circuit breaker.

Yes, they are two different technologies!

If you don't know how to tell the difference between the two either, this article has got you covered! This article highlights the difference between a vacuum circuit breaker (VCB) and an air circuit breaker (ACB).

What is a vacuum circuit breaker?

As the name suggests, a vacuum circuit breaker is a type of circuit breaker that uses vacuum to complete arc extinguishing. The vacuum chamber, also known as a vacuum interrupter, is responsible for opening and closing the current-carrying contacts.

The ** of the vacuum circuit breaker has a steel arch chamber. They are built symmetrically and stacked in ceramic insulators. The vacuum interrupter maintains the vacuum pressure between 10 and 6 bar.

The material used in the transmission contacts in the current can greatly affect the operating performance of the vacuum circuit breaker. Top brands see CR CR as an ideal material for manufacturing vacuum circuit breakers.

The excellent arc provides excellent dielectric strength, making it ideal for medium and relatively high voltage applications. However, they are not the best option for commercial use.

This is why VCBs are often labeled as vacuum circuit breakers in high-voltage chambers. Vacuum circuit breakers are ideal for systems that require voltages from 11 to 33 kV due to their low maintenance requirements.