Difference Between Isolator and Circuit Breaker

The major difference between the isolator and the circuit breaker is that the isolator disconnects the circuit at offload condition whereas the circuit breaker disconnects the circuit at on load condition. The Difference Between Isolator and Circuit Breaker are explained in the comparison chart by considering the factors like the type of device and its action. The operation of the Isolator and Circuit breaker, their functions and the withstand capability.

Difference Between Isolator and Circuit Breaker are given below in the tabulated form.

Comparison Chart

BASISISOLATORCIRCUIT BREAKER
Type of deviceIsolator is an off load deviceCircuit Breaker is an On load device.
OperationIt is operated manually.It is operated Automatically.
Action of deviceIt is a Mechanical device which acts as a switch.It is an Electronic device made by using MOSFET or BJT.
FunctionIsolator cut out a portion of a substation when a fault occurred. The other devices operate without any interruption.

The Circuit breaker is a device such as ACB or MCB, which trips the entire system if there is any fault.
Withstand CapabilityThey have the low withstand capacity as compared to Circuit Breaker.They have the high withstand capability at the on load condition.

An insulator is a disconnecting switch which operates under off load condition. It isolates the part of the circuit in which the fault takes place from the main supply. It is used in high voltage devices such as transformers, etc. Isolators block the DC signals and allow the AC signals to pass.

Circuit Breaker is a protecting device which acts as a switch. It opens and closes the contact of the circuit at the normal as well as when the faulty condition occurs in the system. It automatically disconnects the circuit when an overload current or short circuit takes place.

Difference Between Isolator and Circuit Breaker

  1. An isolator r is an off load device, whereas Circuit Breaker is an On load device.
  2. Isolators are operated manually. Circuit Breakers are operated automatically.
  3. It is an Electronic device made by using MOSFET or BJT. Circuit Breaker is a Mechanical device which acts as a switch.
  4. Isolator cuts out a portion of a substation when a fault occurred. The other devices operate without any interruption. The Circuit breaker is a device known as an Automatic circuit breaker (ACB) or Miniature circuit breaker (MCB), which trips the entire system if any fault occurs and thus the whole system is affected.
  5. Isolators have the low withstand capacity as compared to that of Circuit Breaker.

Hence, in this way, isolator is differentiated from circuit breaker.

2 thoughts on “Difference Between Isolator and Circuit Breaker”

  1. Polycab India Limited

    I was very much confused between isolator and Circuit Breaker, what is it and what is the difference between them, thank you for the perfect explanation.

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