Circuit breaker - what is it? Types and classes of circuit breakers

[vensorelectricals]

A circuit breaker (sometimes also called a "circuit breaker") is designed to disconnect an electrical circuit equipped with it in the event of a short circuit or when the current exceeds a certain value.

 

The operation of a circuit breaker can be based on thermal or electromagnetic principles. It is worth noting that most modern circuit breakers use both of these principles at the same time. How it works is illustrated in Figure 1.

 

The current flowing between the connection points of the machine (A-B) passes through the coil of the electromagnet L and the bimetallic plate 2.

 

When the maximum permissible current value is exceeded, the bimetallic plate heats up (thermal principle), it deforms, activating the S release - a device that opens the electrical circuit.

 

Circuit breaker -   Types and classes of circuit breakers

Electrical wiring circuits in industrial and domestic premises necessarily include more than one circuit breaker. This element ensures the safe operation of not only power grids, but also buildings and structures in general.

 

Residual current device - circuit breaker

 

Need

In the event of a short circuit or exceeding the permissible current loads, it automatically opens the circuit. Disconnecting the load prevents ignition of cable insulation and the spread of fire, damage to expensive equipment, and injury to people.

 

There are many types of circuit breakers, they differ in the power of thermal and current loads, in size, design and other features. At the household level, most of the types of circuit breakers used have general principles of operation and the same set of components.

 

Even the body shapes, holes and individual fastening elements are brought to a common standard. Any type of low-voltage circuit breaker, which is used in office buildings, apartments, private houses, can be easily installed on standard switchboard fasteners.