What Is Circuit Breaker?What Is Circuit Breaker?
Working Principle Of Circuit BreakerWorking Principle Of Circuit Breaker
Arc PhenomenonArc Phenomenon
1. Degree of ionization
2. Length of the arc
3. Cross-section of the arc
High Resistance Method
1. Lengthening the arc
2. Cooling the arc
3. Reducing cross section of
4. Splitting the arc
Low Resistance Method
1.Lengthening of the gap
2. High pressure
Methods Of Arc ExtinctionMethods Of Arc Extinction
Terms Related To Circuit BreakersTerms Related To Circuit Breakers
Different Types Of Circuit BreakerDifferent Types Of Circuit Breaker
Oil Circuit Breaker
Air Blast Circuit Breaker
Sulpher Hexafluroide Circuit Breakers
Vacuum Circuit Breakers
Low Voltage Circuit Breakers
Oil Circuit BreakerOil Circuit Breaker
• These are the oldest type circuit
• The separating contacts are made to
separate within an insulating oil,
which has better insulating properties
• Oil circuit breakers have virtues of
reliability, simplicity and relative
• By connecting several interrupting mechanism in series, the voltage
rating of the breaker can be increased.
• By careful design the interrupting capacity rating can be increased up
to 26000 MVA.
• Quiet operation.
• The breaker contains flammable oil , consequently it should located
• Oil breakdown at high temperature forms carbon which gets dissolved in
the oil, this increases the oil conductivity.
• Becomes an environmental hazard if spillage occurs.
Air –Blast Circuit BreakerAir –Blast Circuit Breaker
• These breakers employ a high pressure air blast as an arc quenching medium.
• The contacts are opened in a flow of air blast.
• The air blast cools the arc and sweeps away the arcing products to the atmosphere.
• This rapidly increases the dielectric strength of the medium between contacts and
prevents from arc.
• The arc is extinguished and flow of current is interrupted.
(i) Axial-blast type (ii)Cross-blast type (iii)Radial-blast type
• The risk of fire is eliminated.
• The arcing products are completely removed by the blast.
• The arcing time is very small due to the rapid build up of dielectric
strength between contacts.
• Air has relatively inferior arc extinguishing properties.
• Air blast circuit breakers are very sensitive to the variations in the rate of
• Considerable maintenance is required for the compressor plant which supplies
the air blast.
The air blast circuit breakers are finding wide applications in high voltage
installations. Majority of the circuit breakers for voltages beyond 110 kV are of
Principle of Operation
Advantage & Disadvantage
Vacuum Circuit BreakersVacuum Circuit Breakers
• Very short arcing time
• High dielectric strength 2 to 3 time that of air
• Noiseless operation
• Minimum maintenance
• Sealing Problems
• Special Facility Required
• Capable of dealing current up to 60 kA and voltages ranges in the range
up to 50-80KV.
• Also developed for voltages 115kV to 230 kV , power ratings 10 MVA to
The purpose of this seminar was the study of circuit breaker,
and we know circuit breaker plays a vital role in power system.
By this seminar we gather new information about circuit
breaker as well as power system, which will help us in other in
the journey of electrical engineering.