Difference Between Isolator and Circuit Breaker

Isolator vs Circuit Breaker

Electricity plays a prominent role in our society. Almost every household appliances and industrial machinery works on electricity. Despite its extreme usefulness electricity can be harmful, when faults occur in the electrical system. Power overloads and short circuits may cause equipment damage. Prevention of such incidents is imminent when installing an electrical system. Isolator and circuit breakers are such prevention systems.

More about Circuit Breakers

A circuit breaker is an automatic switch, which is an on-load device, designed using electromechanical techniques to prevent power overload damage or short circuits. A circuit breaker has a solenoid inside, and it is kept at a certain voltage level, to keep the triggering mechanism in balance. Once a fault is observed in the circuit, such as an overload or a short circuit, the switch is triggered, and the current flow is discontinued. After solving the pertaining problem in the electrical system, the circuit breaker can be switched back to on again.

Like fuses, circuit breakers also come in many different sizes and packages, specialized to the requirements of the electrical system. At higher voltage levels, the circuit breaker mechanism may be immersed in an insulating material, such as oil to improve the performance. More advanced circuit breakers used in industry applications regulate interruptions by small inductive currents, capacitive switching and asynchronous switching. They have current and a voltage rating indicating maximum allowable current and voltage.

More about Isolator

Isolator, on the contrary to the circuit breaker, is an off-load device and performs the task as the name implies. It disconnects or Isolates the circuit from the main power supply. Isolators are most commonly found in industry level electric systems.

Even though, Isolator is a switch, it is not used as a normal on off switch. It is used only when the electrical system has to be disconnected from the main supply, to perform maintenance or related activities, which involve direct contact with the current carrying components of machinery. Isolators may provide additional safety features like, when switched off the trapped charge will be ground through a ground terminal in the isolator. Isolators are normally placed after the circuit breaker allowing the internal circuit to be disconnected from the main supply without affecting the breaker.

Isolators may be used in high voltage devices like transformers. Isolators are secured using a locking mechanism on the outside or by a padlock to prevent inadvertent usage.

In electronics, the term isolator is used to denote a device which separates the internal circuits from the main supply, but it is different from the Isolator switch discussed above. Using opto-couplers an electronics circuit can be isolated such that overloads do not pass through the circuit.

What is the difference between Isolator and Circuit Breaker?

• Isolator is an off-load device while, circuit breaker is an on-load device.

• Isolator is a switch operated manually, which separate the circuit from the power main and discharges the trapped charges in the circuit.

• Circuit breakers operate automatically, triggered by electromechanical mechanism inside and are a safety feature for abnormal loads and voltages in the circuit.