Answer / habib

Circuit breaker is device whcih disconnect the equipment
during fault condition automatically,but isolator does not
disconect the equipment automatically during fault
condition.
Isolator should be operate after deenergizing the
line,because isolator is not having any special arc
quenching facility like sf6 or vaccum in it.cb is having
this facility.
Note:- Isolator is a OFf load device it should follow the
CB operation

Answer / aruna devi

circuit breaker is used to trip during fault condition of
the circuit whereas isolator are the off load is used for
isolate the circuit during maintenance and shutdown

Answer / zahid noor

The basic difference between cicuit breaker & Isolator is,
Circuit breaker ,automatically breaks the circuit
electrically in conditions of fault & overload, where as
Isolator is to be switched OFF manually after tripping the
prevoius protection / drive for the purpose of
maintenance/shutdown.

Answer / sachin

A circuit breaker is designed to break a circuit which is
carrying current at the time. Where large currents and/or
voltages are present, the opening of the circuit may induce
dangerous arcing, so means such as air blast must be used
to "blow out" the arc.

An isolator is only designed to isolate a circuit or other
component after the current has already ceased, so it
doesn't need to have any means to stop the arc.

Thus in high voltage/high current installations such as in
power stations or grid switching stations, the initial
operation to isolate the circuit, whether planned or as a
result of a fault, is by the circuit breaker, the isolator
is then used to isolate the circuit breaker for maintenance
or repair.

Answer / ram niveth

there is no arc quenching medium in isolator .
also we have earth swith in isolator for disharge amd
safety purpose

Answer / bedabyas

The main difference between circuit breaker and isolater is
circuit breaker can operate in any condition ie in full
load to no load condition but isolater can operate in no
load condition.
circuit breaker can operate both manually and
automatically but isolater can operate only manually.

Answer / ayyappan

cir cute breaker used to avoid accident in fault condition
its automatically off Isolater which used to manually off in
fault condition

Answer / shyamalmandirwala

Circuit Breaker is operated ON-LOAD whereas ISOLATOR can
not be operated ON LOAD as it does not have the arc
quenching medium as in the CIRCUIT BREAKER.
ISOLATOR is basically used for disconnecting a portion of
the power system for maintenance work to ensure safety of
persons doing maintenance work.

Answer / princejit singh

CB:-It is used to make or break the ciruit on no as well as
full load.
Isolator:-It is used to make or break the circuit on no load.

Answer / pratheesh

Circuit breaker is a device which is used to cut-off a
online load in normal as well as in Faulty condition.
Which means circuit breakers are designed to cut-off a
cicuit in normal current carrying condition and also in
fault current condition. Such as to switch off a motor in
normal condition and to trip the same in fault condition
with the help of protective relays and devices.

But an isolator is a device which is designed to operate in
offline condition only. Means when there is no current flow
through it. It cannot be operated in when the circuit
breaker is closed condition. There will be both mechanical
as well as electrical interlocks for this. If u operate the
isolator when the loads connected to it running, a flash-
over will be result.

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