All You Need to Know about Air Blast Circuit Breakers: Types and Workin

Circuit breakers are important devices that safeguard electrical networks from current overload and short-circuiting, ensuring safe grid operation and prevention of electrical damage to connected devices and appliances. One of the most important pioneering circuit breaker technologies is the air blast circuit breaker (ACB).  It is designed to quench the arc produced during the interruption of a fault current by a high-velocity air blast.

Let us know more about what is ACB in electrical grids: its construction, operation, types, advantages, as well as disadvantages. 

Air Blast Circuit Breaker – the Working Principle

The fundamental principle behind an air blast circuit breaker revolves around the rapid quenching of the arc that forms when current flow is interrupted. When a fault occurs, the circuit breaker contacts separate, creating an arc due to the ionization of the medium between them. In an ACB, the arc is interrupted by directing a high-velocity blast of compressed air onto the arc zone. The high-speed air cools and sweeps away the ionized gases, facilitating arc extinction. 

Air Blast Circuit Breaker – the Construction

Given below are the main components of an ACB:

1. There is a tank at the bottom of the ACB called an air reservoir which is connected to an air valve. 
2. Three hollow insulator columns can be found on the reservoir tank. 
3. There is a double arc extinction chamber on top of each insulator column.
4. The conducting parts are connected in series to the arc extinction chamber.
5. The main arc extinction occurs in the double arc extinction chamber.  

Air Blast Circuit Breaker – How it Operates

The operation of an Air Blast Circuit Breaker involves the following steps:

1. The auxiliary compressed air system supplies air to the reservoir of the ACB.
2. When a fault occurs, air enters the extinction chamber, pushing apart the moving contacts.
3. An arc is created when contacts get separated. Thus, the arc must be quenched as quickly as possible.
4. The air blast blows away the ionized gases and arcing products, leading to arc extinguishing. Since this procedure occurs very frequently, the arcing time is usually quite minimal for ACBs. 

Air Blast Circuit Breaker – the Different Types

There are three main types of Air Blast Circuit Breakers based on the direction of the air blast and they are as follows:

1. Axial Blast ACB: In this type, the air blast is directed axially along the arc path. 
2. Radial Blast ACB: In this type, the air blast is directed radially towards the arc.
3. Cross Blast ACB:  In this type, the air blast is directed across the arc.

Advantages of Air Blast Circuit Breaker

The biggest and most important advantages of using an ACB are:

1. ACBs offer rapid arc extinction due to the high-velocity air blast, reducing potential damage to the electrical system.
2. They are suited for high-voltage situations with large fault currents. 
3. They require minimal maintenance when compared to other types of circuit breakers, making them cost-effective in the long run.
4. The simple and robust design of ACBs ensures reliable performance in various operating conditions. 

Disadvantages of Air Blast Circuit Breaker

Some of the biggest and most common disadvantages of ACBs are as follows:

1. ACBs require high-quality air compressor systems which can be costly and require maintenance.
2. The release of high-velocity air may cause environmental concerns in some settings.
3. Air leakages are possible at pipe fittings.
4. They are extremely sensitive to voltage restriking.

Uses of Air Blast Circuit Breaker

The air blast circuit breaker is used for fulfilling the following purposes:

1. Traction purposes
2. Arc furnaces
3. Voltage ranges (110kV to 400kV) with 700MVA breaking capacity.

Wrapping up About ACBs

Air Blast Circuit Breakers have been an integral part of electrical networks for many years, offering quick and effective arc interruption capabilities. With their robust design and reliable performance, they continue to serve as essential components in high-voltage applications. With scientific advances, circuit breaker technologies may evolve, but the principles of arc quenching and fault interruption will remain fundamental in ensuring the safe operation of electrical networks around the world.

Read Also: Types Of Circuit Breakers And Their Importance

Schneider Electric eShop - Your One-stop Destination for Purchasing High-Quality ACBs

If you are looking to invest in superior quality Air Blast Circuit Breakers, you need to look no further than the Schneider Electric eShop. Schneider Electric is one of the most trusted names in the market for ACBs as well as other electrical appliances and devices. The eShop houses a wide variety of electrical products, starting from switches and ACBs to home automation systems and electrical safety devices. Visit the website to check out their wide range of ACBs and other products and services offered. Apart from offering the highest quality electrical products in India, all Schneider Electric products are offered at competitive prices with lucrative warranty options. The eShop is a one-stop destination for all your electrical needs!

If you have further queries about ACBs or would like help in finding the most suitable one, feel free to contact the eShop!