Answer / arjun karnti

isolator is a off load device which is used for isolating
the downstream circuits from upstream circuits for the
reason of any maintanance on downstream circuits. it is
manually operated and does not contain any solenoid unlike
circuit breaker. it should not be operated while it is
having load. first the load on it must be made zero and
then it can safely operated. its specification only rated
current is given.

but circuit breaker is onload automatic device used for
breaking the circuit incase of abnormal conditions like
shortcircuit, overload etc., it is having three
specification 1 is rated current and 2 is short circuit
breaking capacity and 3 is instantaneous tripping current.

Answer / senthil kumar

isolator is a off load device ie we cant able to close the
isolator under onload condition if we close the isolator
under onload it will damage the isolator but breaker is a
device having high withstand capacity(the withstand
capacity is based on application)so we can able to open
&close the breaker under both onload &offload
conditions......and also while opening &closing under
onload arc will appears at the contacts. the isolator have
no special arrangement to extinguish that arc but in
breaker we have some special arrangement to extinguish that
arc.

Answer / mike.vikram

Circuit breaker is the device such as ACB's or MCCB's which
trips the entire system if there is a failure. By the entire
system we mean the elements connected to the particular
busbar of that crcuit breaker.
An isolator is used to cut out a portion of a substation
when a fault has occured on a particular portion of the
whole station to rectify it and repair it and in the
meanwhile the other devices operatee without being affected
by the faulty part.

Answer / azeezur rahman

isolator is a off load device which is used for isolating
the downstream circuits from upstream circuits for the
reason of any maintanance on downstream circuits. it is
manually operated and does not contain any solenoid unlike
circuit breaker. it should not be operated while it is
having load. first the load on it must be made zero and
then it can safely operated. its specification only rated
current is given.

but circuit breaker is onload automatic device used for
breaking the circuit incase of abnormal conditions like
shortcircuit, overload etc., it is having three
specification 1 is rated current and 2 is short circuit
breaking capacity and 3 is instantaneous tripping current

Answer / dipak patil

the main difference beetween Isolator and CB is that,
isolator has no Making or braking capacity, that is that it
cann't break or make the circuit that carrying load current
unlike circuit breaker. CB can make as well as break the
circuit under normal load condition or under fault
condition.Under fault condition protection operates CB.
Both Isolator and CB can be operated manualy or
automaticaly as per application.

Answer / ramakrishnan.k

Isolator to be operated manually like switch.And circuit
breaker isolate the circuit automatically when there is
fault or over load in the circuit breaker.

Answer / venkatesan.j

An isolator is an off load device witch can be operated
only when the current is zero where as the Circuirt breake
ris an on load devce whitch can be operate both in live and
current zero condition.

Answer / reddyprasad

isolator is a off load device which is used for isolating
the downstream circuits from upstream circuits for the
reason of any maintanance on downstream circuits. it is
manually operated and does not contain any solenoid unlike
circuit breaker. it should not be operated while it is
having load. first the load on it must be made zero and
then it can safely operated. its specification only rated
current is given.

but circuit breaker is onload automatic device used for
breaking the circuit incase of abnormal conditions like
shortcircuit, overload etc., it is having three
specification 1 is rated current and 2 is short circuit
breaking capacity and 3 is instantaneous tripping current.

Answer / vaika

circuit breaker is an automatic device capable ofmaking or
breaking an electrical circuit under normal or abnormal
conditions such asshort circuits . we can operate this in
onload condition.
isolator switch is used to make sure that an electrical
circuit can be completely de-energized for service it is an
off load operating device

Answer / rupeshwar kumar priy

isolator is off load device because in case on load occur
fault condition when contact is open arc is produced and
isolator have no arc quenching medium so firstly operate
circuit breaker.
circuit breaker is on load device because on load fault
condition arc is produced CB have arc quenching medium
air, oil etc. which is helpful and so it break the circuit
and after isolator open to maintenance process start but in
case contact first isolator is closed then circuit breaker
is closed.

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