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Air Blast Circuit Breaker
under the guidance of:-
Presented By:-
Mr. B.R.Reddy
Anuj Kumar Pandey
EN-3rd year
Roll No. 0813321016
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INTRODUCTION
 CLASSIFICATION
 ADVANTAGES
 DISADVANTAGES
 APPLICATIONS
 FUTURE PERSPECTIVE
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An electrical power system is very complex. It
needs some form of switchgear in order that it
may be safely and efficiently controlled or
regulated under both normal and abnormal
operating conditions.
Circuit breaker is an automatically operated
electrical switch.
It protects an electrical circuit from damage
caused by overload and short circuit.
Its basic function is to detect a fault condition
and, by interrupting continuity, to immediately
discontinue electrical flow.
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Unlike a fuse, which operates once and then
has to be replaced, a circuit breaker can be
reset (either manually or automatically) to
resume normal operation.
It can be of various size , from small device
that protects the appliances of an household
to large to protect the entire city.
FUNCTIONS:It carries the full load current continuously
without over heating or damage.
 It opens and closes the circuit on no load.
 It makes and breaks the normal operating
current.
 It makes and breaks the short circuit current of
magnitude up to which it is designed for.

 The
circuit breaker can be classified
on the basis of the quenching
(cooling) medium:
1.
2.
3.
4.
5.
6.
Air circuit breaker
Air blast circuit breaker
Tank type bulk oil circuit breaker
Minimum oil circuit breaker
SF6 circuit breaker
Vacuum circuit breaker
 AIRBLAST
CIRCUIT BREAKER
 These
type of breakers employ ‘air blast’ as the
quenching medium.
 The contacts are opened by air blast produced by
the opening of blast valve.
 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
re-establishing the arc.
 So the arc is extinguished and the flow of current
is interrupted.
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Types
of Air blast circuit breaker
(1). Axial-blast type
(2).Cross-blast type
(3).Radial-blast type
1)
Axial-blast type:-
In which the air-blast is
directed along the arc path as
shown in Fig.
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2) Cross-blast type:In which the air-blast is
directed at right angles to the
arc path as shown in Fig.
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(3) Radial-blast type:In which the air-blast is
directed radially as shown
in Fig
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The risk of fire is eliminated.
 The arcing products are completely removed by the
blast
 The growth of dielectric strength is so rapid that
final contact gap needed for arc extinction is very
small. This reduces the size of device.
 The arcing time is very small due to the rapid build
up of dielectric strength between contacts
 Due to lesser arc energy, ABCB are very suitable for
conditions where frequent operation is required
 The energy supplied for arc extinction is obtained
from high pressure air & independent of the current
to be interrupted
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
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Air has relatively
properties.
inferior
arc
extinguishing
Air blast circuit breakers are very sensitive to the
variations in the rate of restriking voltage.
Considerable maintenance is required for the
compressor plant which supplies the air blast .
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 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 this type.
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◦ In the near future, present interrupting
technologies can be applied to circuit-breakers with
the higher rated breaking currents (63 kA to 80 kA)
required in some networks with increasing power
generation.
Thank you