Date post: | 21-Jan-2017 |
Category: |
Engineering |
Upload: | dilip-kumar |
View: | 278 times |
Download: | 4 times |
GUIDED BY:- Mr. Piyush Sharma
H.O.D (EEE/EE)SS College of Engineering Udaipur (Rajasthan)
PRESENTED BY:- Dilip Kumar Roll no. :-12ECOEE005
TRAINING SEMINARON
CIRCUIT BREAKER
SESSION 2015-16Bachelor of Technology
InElectrical Engineering
CONTENTSCircuit breaker.Types of circuit breaker(C.B).Oil circuit breaker. i bulk oil circuit breaker. ii minimum oil circuit breaker.Air blast circuit breaker.SF6 circuit breaker.Vacuum circuit breaker.
Circuit Breaker• A circuit breaker is a piece of equipment which can Make or break a circuit either
manually or by remote control under normal conditions.• Circuit breaker sense the message from relay and break the circuit.
• Make a circuit either manually or by remote under fault condition.
Circuit Breaker
TYPES OF CIRCUIT BREAKER
• AIR CIRCUIT BREAKER.• OIL CIRCUIT BREAKER.• VACCUM CIRCUIT BREAKER.• SF6 CIRCUIT BREAKER.
Air Circuit Breakers
1.In this Circuit Breaker the arc is elongated using arc runners and arc splitters so as to increase the resistance of the arc.
3.This increases the voltage required to maintain the arc and if the available voltage cannot sustain the arc ,the arc gets extinguished.
2.At current zero ,the recovery voltage across the contacts becomes less than the arc voltage and the arc gets extinguished.
4. The energy in the system inductance at current zero is zero .Hence arc interruption is easier.
Air Circuit Breakers
Advantages and Disadvantages
AdvantagesHigh speed of operationShort arcing timeHigh speed reclosingLess weight as compared to oil
circuit breakersVery less maintenanceNo possibility of explosion
DisadvantagesCost is moreFor complete compress air
installation is requiredFor operation and
maintenance ,highly skilled required
Vacuum Circuit Breaker
• Vacuum is used as an arc quenching medium.• Have greatest insulating strength.• 10-7 to 10-5 pressure is to be maintained.• Used in 11KV panel in control room of grid station.
Vacuum Circuit Breaker
Vacuum Circuit Breakers
Advantages Compact in sizeReliable and long lifeHeavy fault can be interrupted
effectivelyNo gas is generated after arc
extinction operationOperation is not noisyArc energy is lowNo risk of fire
DisadvantagesVacuum has to be maintained at
desired level always
Bulk Oil Circuit Breaker
Advantages
• oil has high dielectric strength.• Oil absorbs arc energy while
decomposing.• Good cooling property of the gas
formed due to decomposition.• It acts as an insulator between the live
parts and earth.
Disadvantages• Long arcing time.• Do not permit high speed of
interruption.• Bulk size.
Bulk Oil Circuit Breakers
Minimum Oil Circuit Breaker
Minimum Oil Circuit Breaker
AdvantagesRequires less quantity of oilRequires smaller spaceMaintenance is lessCost per breaking capacity in MVA is
lessSuitable for both manual and
automatic operation
DisadvantagesPossibility of fire and explosion.Difficult to remove gases from the
space between contacts.Oil deteriorates rapidly due to
carbonizationSmaller quantity of oil, so
carbonization increases.
SF6 circuit Breaker (Properties of SF6 gas)
Rate of rise of dielectric strength is very high.Can be liquefied and stored in steel tanks.Dielectric strength increase linearly with pressure.Gas is inert. Therefore contacts will not get eroded.Gas is non –inflammable , Colorless ,odorless, Non-toxicThermally stable up to 55 degrees.
Sulfur Hexafluoride Circuit Breaker(SF6)
THANK YOU