What is the Difference Between Isolator and Circuit Breaker?

The main difference between an isolator and a circuit breaker lies in their purpose and functionality. Here are the key differences between the two:

1. Purpose: An isolator is a disconnecting switch used in an electrical circuit to ensure that the circuit is completely isolated from the supply mains. Circuit breakers, on the other hand, are protective electrical devices that work as a switch, stopping the flow of electric current through the circuit whenever necessary.
2. Application: Isolators are mainly used in industrial electrical systems, while circuit breakers are widely used in both industrial and domestic settings.
3. Operating Conditions: An isolator is an off-load device, meaning it can only be operated when the current flowing is zero, i.e., when the power supply is off. Circuit breakers are on-load devices, designed to protect against overload by interrupting power from short circuits and overload faults.
4. Arc Suppression: Isolators do not have an arc extinguishing system, while circuit breakers have an electromechanical switch, a relay, and an arc extinguishing system.
5. Installation: Isolators are installed on both sides of the circuit breaker, while circuit breakers are installed in the circuit.
6. Breaking Capacity: Isolators are not used to break load faults, while circuit breakers protect the circuit by interrupting power from short circuit and overload faults.
7. Number of Poles: Isolators are designed to have a higher number of poles than circuit breakers.

Both isolators and circuit breakers are crucial components in electrical power systems, ensuring the safe operation of electrical equipment and protecting against faults and damage.

Comparative Table: Isolator vs Circuit Breaker

Here is a table comparing the differences between isolators and circuit breakers:

Isolators and circuit breakers are both electrical devices used in power distribution systems, but they serve different purposes and have distinct properties.