What are the differences between isolating switch and circuit breaker?

Isolating switch and circuit breaker have obvious differences in function, structure, operation mode and safety. Appropriate equipment should be selected according to actual needs.

contents

Functional difference

Structural difference

Operation mode difference

Operation occasion difference

Safety difference

Functional difference

Isolating switch: Mainly used to isolate power supply to ensure the safety of maintenance work. It can cut off the circuit under no load, but does not have arc extinguishing function, so it cannot be used to cut off load current or short-circuit current.

Circuit breaker: Not only has the function of isolating power supply, but also has arc extinguishing device, which can cut off the circuit under load, and can also cut off short-circuit current, playing a role in protecting the circuit.

Structural difference

Isolating switch: The structure is relatively simple, mainly composed of contacts, base, support insulator, connecting rod, etc., without arc extinguishing device.

Circuit breaker: The structure is complex, usually composed of contact system, arc extinguishing system, operating mechanism, tripper, insulating shell, etc., with arc extinguishing function.

Operation mode difference

Isolating switch: usually manual operation is adopted on site, and the operator needs to operate on site.

Circuit breaker: mostly remote control electric operation is adopted, which can be controlled at a distance.

Operation occasion difference

Isolating switch: mainly used to ensure the safety of maintenance, and used when the power supply needs to be isolated.

Circuit breaker: in addition to isolating the power supply, it is also used to protect the circuit, cut off the load current and short-circuit current, and is widely used in various circuit protection occasions.

Safety difference

Isolating switch: there is no arc extinguishing function, it cannot be used to cut off the load current or short-circuit current, and there are certain safety hazards.

Circuit breaker: with arc extinguishing function, it can safely cut off the load current and short-circuit current, and improve the safety of the circuit.

In summary, the isolating switch only plays an isolating role. If there is a fault in the subsequent circuit, it cannot be automatically disconnected, but the circuit can be manually disconnected during maintenance to ensure the personal safety of the maintenance personnel. The isolating switch is generally used on the high-voltage side to isolate the circuit. It is mainly installed to provide an obvious separation point for maintenance, and is generally used in conjunction with a short-circuit breaker.

Circuit breakers are the most widely used, with functions far exceeding other switches and a number of parameters. They can not only isolate, but also protect the subsequent lines and equipment. They have thermal magnetic protection components, can add a variety of accessories, and can be remotely controlled. Circuit breakers are used for high and low voltages and have a protective effect. Some high voltage ones have arc extinguishing functions.