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Types of Circuit Breaker

1. Oil Circuit Breaker 1. Oil Circuit Breaker

:-In

In an an oil oil circuit circuit breaker breaker with with simple simple interruptioninterruption under oil, the duration of arcing is 0.02-0.05 sec.

under oil, the duration of arcing is 0.02-0.05 sec.

To extinguish the arc more efficiently, To extinguish the arc more efficiently,

arc-quenching chambers are used. In a longitudinal quenching chambers are used. In a longitudinal blast chamber the vapors and gases evolved

blast chamber the vapors and gases evolved travel upward along the arc,

travel upward along the arc, thus cooling it. Inthus cooling it. In addition, the arc is in contact with the

addition, the arc is in contact with the cold oilcold oil that fills the annular slots of the chamber,

that fills the annular slots of the chamber, whichwhich also accelerates cooling of the arc. In a

also accelerates cooling of the arc. In a

transverse blast chamber a drastic pressure transverse blast chamber a drastic pressure

increase within the gas bubble causes a stream increase within the gas bubble causes a stream of oil and gases to flow

of oil and gases to flow across the arc, thusacross the arc, thus accelerating the cooling process.

accelerating the cooling process.

2. Air Blast Circuit Breaker 2. Air Blast Circuit Breaker

:-High

High pressure pressure air air at at a a pressure pressure between between 20 20 to to 3030 kg/ cm2 stored in the air reservoir. Air is taken

kg/ cm2 stored in the air reservoir. Air is taken from the compressed air system. Three

from the compressed air system. Three hollowhollow insulator columns are mounted on the r

insulator columns are mounted on the reservoireservoir with valves at their basis. The double arc

with valves at their basis. The double arc

extinguished chambers are mounted on the top extinguished chambers are mounted on the top of the hollow insulator chambers. The current of the hollow insulator chambers. The current carrying parts connect the three arc

carrying parts connect the three arc extinctionextinction chambers to each other in seri

chambers to each other in series and the pole toes and the pole to the neighbouring equipment. Since there exists the neighbouring equipment. Since there exists a very high voltage between the conductor and a very high voltage between the conductor and the air reservoir, the entire arc extinction

the air reservoir, the entire arc extinction

chambers assembly is mounted on insulators.

chambers assembly is mounted on insulators.

3. Vaccum Circuit 3. Vaccum Circuit

Breaker:-A

A vacuum vacuum circuit circuit breaker breaker is is such such kind kind of of circuitcircuit breaker where the arc quenching takes place in breaker where the arc quenching takes place in vacuum. The technology is suitable for mainly vacuum. The technology is suitable for mainly medium voltage application. For higher voltage medium voltage application. For higher voltage Vacuum technology has been developed but not Vacuum technology has been developed but not commercially viable. The operation of opening commercially viable. The operation of opening and closing of current carrying contacts and and closing of current carrying contacts and associated arc interruption take place in a associated arc interruption take place in a vacuum chamber in the breaker

vacuum chamber in the breaker which is calledwhich is called vacuum interrupter. The vacuum interrupter

vacuum interrupter. The vacuum interrupter consists of a steel arc chamber in

consists of a steel arc chamber in the centrethe centre symmetrically arranged ceramic

symmetrically arranged ceramic

insulators.Service life of Vacuum Circuit Breaker insulators.Service life of Vacuum Circuit Breaker is much longer than other types of

is much longer than other types of circuitcircuit breakers.

breakers.

4. SF

4. SF₆₆ Circuit Breaker :- Circuit Breaker

:- A circuit breaker

 A circuit breaker in which the current in which the current carrying contacts carrying contacts operate in Suloperate in Sulphurphur Hexafluoride or SF6 gas is known as an SF6 Circuit Breaker.

Hexafluoride or SF6 gas is known as an SF6 Circuit Breaker.

SF6 has excellent insulating property. SF6 has

SF6 has excellent insulating property. SF6 has high electro-negativity. Thathigh electro-negativity. That means it has high affinity of

means it has high affinity of absorbing free electron. Whenever a freeabsorbing free electron. Whenever a free electron collides with the SF6 gas molecule, it is absorbed by that gas electron collides with the SF6 gas molecule, it is absorbed by that gas molecule and forms a negative ion.

molecule and forms a negative ion.

The attachment of electron with SF6 gas molecules may occur in

The attachment of electron with SF6 gas molecules may occur in tow differenttow different ways,

These negative ions obviously much heavier than a

These negative ions obviously much heavier than a free electron and thereforefree electron and therefore over all mobility of the charged particle in the SF6 gas is much less as

over all mobility of the charged particle in the SF6 gas is much less as

compared other common gases. We know that mobility of charged particle compared other common gases. We know that mobility of charged particle is majorly responsible for conducting current through a gas.

is majorly responsible for conducting current through a gas.