do u know the main difference between isolator and circuit breaker?

20 Answers

  • Anonymous
    1 decade ago
    Favorite Answer

    Major difference between isolator and circuit breaker is that isolator is an off-load device, whereas circuit breaker is an on-load device.

    (An isolator switch is part of an electrical circuit and is most often found in industrial applications. The switch does exactly what its name suggests in that it electrically isolates the circuit or circuits that are connected to it. Such a switch is not used normally as an instrument to turn on/off the circuit in the way that a light switch does. Either the switch isolates circuits that are continually powered or is a key element which enables an electrical engineer to safely work on the protected circuit.

    Isolator switches may be fitted with the ability for the switch to padlock such that inadvertent operation is not possible. In some designs the isolator switch has the additional ability to earth the isolated circuit thereby providing additional safety. Such an arrangement would apply to circuits which inter-connect power distribution systems where both end of the circuit need to be isolated.

    An isolator is a switch connected after a circuit breaker. When a circuit or a busbar is taken out of service by tripping the circuit breaker, the isolator is then open circuited and the isolated line is earthed through earth switch so that the trapped line charges are safely conducted to ground.

    A circuit breaker is a complex circuit -breaking device with the following duties:

    Make or break both normal and abnormal currents,

    Appropriately manage the high-energy arc associated with current interruption. The problem has become more acute due to interconnection of power stations resulting in very high fault levels,

    Effect current interruption only when it is called upon to do so by the relay circuits. In fact they are required to trip for a minimum of the internal fault current and remain inoperative for a maximum of through fault current,

    Rapid and successive automatic breaking and making to aid stable system operation,

    3-pole and single pole auto-relosing arrangement.

    In addition to these making and breaking capabilities, a circuit breaker is required to do so under the following typical conditions:

    Short-circuit interruption

    Interruption of small inductive currents

    Capacitor switching,

    Interruption of short-line fault,

    Asynchronous switching.

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  • 1 decade ago

    The Main difference between an Isolator and a CB is:

    An Isolator is usually a manual device, which needs to be operated manually to cut off a circuit.

    A circuit Breaker is a protection device which trips automatically in the event of a fault in the circuit.

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  • 1 decade ago

    A circuit breaker is designed to interupt a circuit when a certain current level is exceeded. Its purpose is to protect wires and equipment from damage due to shorts or excessive loads.

    An isolator is designed to make sure that a secondary power system cannot connect into the main system. Homes with generators wired directly into them must have an isolator that keeps the generator from connecting to the power grid. This is designed to protect electrical workers from injury working on lines that are supposed to be dead, among other things. When electrical power is interrupted, the isolator can disconnect the house so the generator can provide power separately, then reconnect to switch back.

    There is another type of isolator, usually called a voltage isolator, that works like an inductor or transformer but doesn't change voltage. This is designed to provide power without a direct connection to the power source.

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  • 1 decade ago


    There are 5 types of circuit breakers that is

    1)Air Circuit Breaker(ACB)

    2)Vaccum Circuit Breaker(VCB)

    3)Oil Circuit Breaker(OCB)

    4)Moulded Case Circuit Breaker(MCCB)

    5)Miniature Circuit Breaker (MCB)

    the main advantage of circuit breakers are we can set a current flowing through that circuit breakers. if the current exceeds the limits the circuit breaker trips.

    In industry ACB are used in GEN SET distribution areas and nonlinear loads used areas.VCB are used in HT rooms. In ACB & VCB the air and the vaccum are used as the spark supressor respectively.


    Isolators are used not to break the the circuits. For example we can take "OPTO COUPLER".it is an isolator.if there is electrical and electronics combined machines we must use a isolater in the circuits.if we did not done that means then there is damage will occur in PCB's.Opto coupler will give an eletrical isolation.

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  • 5 years ago

    This Site Might Help You.


    do u know the main difference between isolator and circuit breaker?

    Source(s): main difference isolator circuit breaker:
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  • 1 decade ago

    The isolator is generally used in industrial applications to electrically isolate a circuit or circuits connected to it so they can be checked or worked on without shutting down the entire system.

    A circuit breaker shuts down a circuit automatically in the event of an overload.

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  • 1 decade ago

    Circuit Breaker is a Physical Device,

    In simple terms it is called a Switch, it literally disconnects part of circuit from main circuit.

    Where as,

    Isolators are Electronics Device, mainly made using MOSFET or BJT, when Gate voltage drops below certain level, the device shuts off, and whatever is connected to sourse is isolated (it is not flowing any current, it is still in circuit, just with infinate resistance)

    so in simple words,

    Circuit Breaker = Mechanical Switch

    Isolators = Electronics Switch



    Source(s): I am an EE
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  • 1 decade ago

    An isolator will isolate a circuit by the use of switches.

    A circuit breaker is a safety switch.

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  • 6 years ago

    actually, everybody did answered very well. but I just want to contribute a little. Isolator are of kinds, but manually operated to cut off a live circuit when a fault arise in that circuit or a machine and to boot up a cct also when the fault is traced. while a cct breaker is a mechanical or protective device that automatically trip off a cct either when an excessive current flow in or when a cct is overloaded. Thank you so much a really appreciated for given me the chance to comment or contribute my little knowledge.

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  • puga
    Lv 4
    3 years ago

    Electrical Isolator

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