How Do Vacuum Circuit Breakers Work?

What is the vacuum circuit breaker?

What is VCB breaker? A vacuum circuit breaker is also known as the type of circuit breaker where the extinguishing arc can take place in the vacuum medium. The performance of the switching off or on the currents that carry the contacts and the reticulated arc interruption fits within the vacuum chamber in the breaker which is known as the vacuum interrupter. It is noted that we will discuss here how do vacuum circuit breakers work.

However, a vacuum that can be operated arc quenching medium within a circuit breaker is known as the vacuum circuit breaker since the vacuum provides the high insulating strength which is required for the properties of the upper-level ac quenching. This is appropriate for the better applications for the voltage as a consequence of the vacuum technology, standard voltage was improved in a better way, although, it is not lucratively attainable.

How Do Vacuum Circuit Breakers Work?

How do vacuum circuit breakers work? The main working principle of the vacuum circuit breaker is to remove arc energy from circuit breaker contact (moving and fixed contact). Whenever the contacts of circuit breakers are opened inside the vacuum (10−7 to 10−5 torr), then an arc can be originated from the contacts with the help of metal vapor ionization within the contacts. However, the arc can be extinguished easily since, the ions, metallic vapor, and electrons can be originated from the arc which can directly condense above the CB contacts surface area, to experience a quick improvement in the strength of the dielectric.

vacuum circuit breaker working process

The important characteristics of the vacuum are that when the arc is originated inside the vacuum it can easily and quickly be quenched due to the fast advancement rate within the dielectric strength of the vacuum. Generally, vacuum circuit breakers are used in the systems of high-voltage electronics to complete the paired functions of the breakers within the panels of indoor electronics.

The properties of the Vacuum Circuit Breakers are:

Among the circuit breakers, the vacuum circuit breaker insulating medium has a better maximum capacity for the destruction of the arc. Approximately, the vacuum interpreter pressure has a 10-4 torrent that requires little atoms within the interrupter. There are only two extraordinary properties of the circuit breaker.

This circuit breaker consists of a splendid dielectric medium that can be contrasted with the other alternative insulating media that can be utilized in the circuit breakers. The vacuum circuit breaker is considered the best which can be compared with the Air circuit breaker and the SF6.

The prime current can be broken at zero only after keeping the contact inside the vacuum and unlocking the separate arc. The arc’s interference can enhance the dielectric’s strength up to thousand times if it has been differentiated from some other types of breakers. Having these properties can make the circuit breakers efficient, cheap cost, and floaty weight and it does not even need any special or expensive maintenance.

The important pieces of vacuum circuit breakers are tie bars, flexible connections, terminals, vacuum interpreters, operating rods, normal operating shift, locking cam, operating corn, spring forming, breaker spring, main link, loading spring, and support insulator.

Where vacuum circuit breakers are used?

Vacuum Circuit Breaker is recognized as the type of circuit breaker which utilizes the vacuum that connects the electrodes as a part of an arc quenching medium. The vacuum circuit breakers are used for the applications of voltage medium and here, the range of the supply voltage is from 11kV to 33 kV. During the VCB, the circuit breakers’ contacts remain surrounded by the entirely sealed vacuum cylinder.

VCB breaker

Since the vacuum is inside the contacts, the contacts get divided where no arc can be generated. The great benefits of the vacuum circuit breaker are that they do not need much maintenance, no emission of gas can be found in the atmosphere, high life span, silent performance, and they have fewer risks from the danger of fire. The vacuum circuit breakers are appropriate for the applications of the indoor.

Why do we use vacuum circuit breakers?

We should know that vacuum circuit breakers and SF6 circuit breakers both are used for high-voltage applications. A vacuum circuit breaker provides better insulating strength. It contains better arc quenching properties than the other types of mediums.

  • Vacuum circuit breakers can be the best circuit breaker since it has a long lifespan.
  • Unlike any other circuit breakers, such as air blast circuit breakers (ABCB) and Oil Circuit Breakers (OCB), for the vacuum circuit breaker, the outburst can be avoided which ensures the security of the operating personnel.
  • There will be no fire danger.
  • The vacuum circuit breaker is best to clean the fault which can operate quickly. It is appropriate for the repeated operation.
  • The vacuum circuit breakers require no maintenance.
  • There will be no depletion of gas in the atmosphere and it will operates in silently. 

The vacuum circuit breaker has a better switching capacity and it can switch the currents from low values into the perfect system of the short circuit current. In this electronics, it contains high endurance which can range from 10k – 50k actions for the vacuum that can be rated for the steady current. At a complete short circuit rating, it contains 30 to 100 operations.

This device is not appropriate for the applications of maximum endurance which can be operated electronically. This device is automatically locked because; the circuit breaker is closed with the system of system loss. This device operates with protective relays. Here, the short circuit proceeds through low energy. For this device, remote operation is appropriate. To maintain the circuit breaker, space heaters, and secured relays the control power is used widely. This device can be used in a broad area.

Types of Vacuum Circuit Breaker

The Atmospheric Vacuum Breaker incorporates the air vent and the check valve. The device lets the air proceed toward the system to impede a siphon for the point of use. The Hose Connection Vacuum Breakers are located on the faucets and hose bibs which can reduce the backflow from the supply of water.

A Pressure Type Vacuum Breaker is equivalent to the Atmospheric Vacuum Breaker and contains a spring with a check valve to empower the operation of the under pressure for lengthy periods. Spill Resistant Vacuum Breakers use the check valve and the air vent inlet permits the air to enter until the internal check valve opens, therefore, saving the water spillage which is connected with the Pressure Type Vacuum Breakers.

Where would you find a vacuum breaker?

The vacuum circuit breaker (VCB) is frequently placed over the valve of the bibcock or urinal flush valve or toilet that stops the water from being word piped in backward which proceeds to the system of drinking water. Besides that, these vacuum breakers can be located near the flush or box which is situated at the ground level,  outside of the home, or else can be located in the basement near systems of irrigation where water shutoff and near the main water pipe of the home.

Final thought

How do vacuum circuit breakers work? VCB breaker is a vacuum circuit breaker where arc quenching takes place in a vacuum medium. Indeed circuit breaker has two contacts fixed contact and moving contact. If the breaker medium becomes ionized then fixed contact and moving contact become separated and the arc is struck between them.  We have to remove this arc energy vacuum circuit breaker that has the highest arc-removing energy that can completely remove the arc energy between the contact or de-ionize the particle and both contacts become closed and the supply can flow continue (healthy situation). For this reason, the vacuum circuit breaker is used for high-voltage applications. Get in touch with openread to get more innovative things.

See the Related Post

How often do circuit breakers go bad?

Circuit Breaker Selection Guide

Best Circuit Breaker Finder

Best Circuit Breaker for Low Voltage

Double Pole Circuit Breaker

SF6 Circuit Breaker Working Principle

Leave a Comment