Arc Extinction In Circuit Breaker

This is the main drawback of this method of arc extinction and so its use is restricted to dc circuit breakers and air break type ac circuit breakers of relatively low capacities of the.

Arc extinction in circuit breaker.

In this method the arc resistance is increases gradually so that current is reduced to such a value that heat is insufficient to maintain the arc. There are two methods of extinguishing the arc in circuit breaker. In air blast circuit breaker or in breaker where a gas flow is present between the electrical contacts the heat loss of arc plasma occurs due to convection process. In circuit breaker with plain break arc in oil arc in chutes or narrow slots nearly all the heat loss due to conduction.

It pushes away the moving contacts. The arcing resistance increases with decrease in the cross sectional area of the arc. As the separation between the contacts of breaker increases the arcing resistance also increases. In high resistance method the arc resistance is made to increase gradually with the time so that the current force in between the two contacts is insufficient to maintain the arc.

The main designing criteria of a circuit breaker is to provide appropriate technology of arc quenching in circuit breaker to fulfill quick and safe current interruption. Principle of arc extinction in circuit breaker. Cross section of the arc. Therefore while designing the circuit breaker provision of mechanical strength to withstand such sudden release of large quantities of energy must be made.

Principles and methods of arc extinction are discussed here. In doing so the contacts are pulled apart and the air blast moves away the. The arc resistance increases as the length of arc increases i e. Arc extinction when the current carrying contacts of the circuit breaker are moved apart an arc is formed which insist for a short period after the separation of contacts.

1 high resistance method. The air blast needs an additional compressed air system which supplies air to the air receiver. Hence the current is. This arc is dangerous on account of the energy generated in it in the form of heat which may result in explosive force.

These are high resistance methods and low resistance or zero resistance method. Methods of arc extinction in circuit breaker. When opening air is required compressed air is admitted to the arc extinction chamber. There are two methods of extinguishing the arc in circuit breakers.