What is air circuit Breaker and air circuit breaker types

Sarmad

April 01, 2020

0

circuit breaker, Electrical

What is Air Circuit Breaker ( ACB )

The circuit breaker in which the air is used to extinguish the arc is called an air circuit breaker.

There are two types of it:

1. Air Break Circuit Breaker
2. Air Blast Circuit Breaker

Air Break Circuit Breaker

A circuit breaker that is used to extinguish the arc at normal air pressure is called an air Break circuit breaker. Its operating mechanism usually works via a pre-charged spring. As the contacts are separate, an arc is created between them. The air surrounding the arc is also ionized due to the temperature of the arc core. Cooling the arc reduces the diameter of the arc cover. The arc is extinguished, cooled, and dispersed. Doing so increases the resistance of the arc to such an extent that the system voltage, parallel to the contacts, cannot maintain the arc and the arc is extinguished. This breaker is used for low and medium voltage.

Air brake AC circuit breakers are widely used for industrial switchgear and relief switchgear at generating stations. Arc resistance in AC air breakers decreases rapidly as a result of the rapid rise and passage of air between contacts. As the current of arc resistance decreases, the current decreases. Thus the fault current on the first Zero crossing will be zero for a while and the voltage on the contacts will increase. If this voltage is higher than the insulation strength of this state of the medium, the arc between contacts will be restored and the other current will remain at zero and then quench.

The arc extinguishers in the DC system are a bit different and difficult. From contact, the arc is transmitted through the breeze to the arc runners. Which makes the arc taller and cooler. Which increases the resistance of the arc. Thus the arc voltages become even higher. When the arc voltage exceeds the supply voltage. So the arc current drops to zero at zero. If the arc voltage is lower than the supply voltage, the arc will continue to burn and the contacts will be damaged. It is important for circuit breakers at Natural Current Zero to work fast and be able to increase the medium's insulation strength within a few milliseconds. I am. Air circuit breakers are suitable for continuous operation. Due to the simplicity in textures, they have to be repaired.

Air Blast Circuit Breaker

Airblast circuit breakers are breakers that use high-pressure air to extinguish the arc. Nowadays air blast circuit breakers are used for various purposes from 11 to 1100 kV. These breakers are more robust, more speedy, more suitable for frequent running than oil circuit breakers. Auto recycles are more popular because of the simple assembly, unit type multi-brake textures and proper repair A compressor plant is essential to maintain high air pressure in the air receiver. These circuit breakers are suitable for this location. Where frequent circuits need to be switched on / off. Such as railways and arc furnaces. In addition, interconnected lines and main lines where high-speed operation is required, air blast circuit breakers are also used.

This type of circuit breaker is used to extinguish compressed air at high pressure. And these breakers are used to achieve optimal purposes in any system that operates from 132 kV to 400 kV. Such circuit breakers are now being made that can be used for a range of 6.6 kV to 132 kV. Compressed air plant is required to achieve high pressure. By which air is deposited in the air reservoir to maintain air pressure. Compressed air is thrown directly at the arc generated between them at the moment of separation of contacts. It also cools the air arc and lengthens the arc so that the arc extinguishes only one arc on a low voltage circuit breaker. The dispenser is a chamber, however, it has become common for high-voltage circuit breakers to use two or more identical arc flicker chambers connected to each pole to ensure immediate arc removal. General Chat Chat Lounge