The circuit breaker is a very basic low-voltage apparatus. The circuit breaker has overload, short circuit and undervoltage protection functions, and has the ability to protect lines and power supplies.? The usage and function of air switch and circuit breaker are similar! Only the air switch is generally used in situations with small load, and the circuit breaker is generally used in situations with relatively large load!? According to the different arc extinguishing mediums used, circuit breakers include air circuit breakers (commonly known as air switches), vacuum circuit breakers, SF6 circuit breakers, oil circuit breakers, etc. In the electrical design of civil buildings, the voltage is mostly 220~380V, and the arc extinguishing medium of the circuit breaker is air, so the air switch or circuit breaker are both right. However, for the power system, it is necessary to specifically treat the identification. The main types of circuit breakers are:? Molded case circuit breaker, creepage circuit breaker, miniature circuit breaker, high section miniature circuit breaker, high section miniature creepage circuit breaker, miniature creepage circuit breaker, intelligent universal type.
The working principle of the circuit breaker is that when the short circuit occurs, the magnetic field generated by the large current overcomes the reaction spring, the release pulls the operating mechanism to act, and the switch trips instantaneously.
When the overload occurs, the current becomes larger, the heat is increased, and the bimetallic sheet deforms to a certain extent to push the mechanism to act. The greater the current, the shorter the action time.
The circuit breaker is of electronic type. The transformer is used to collect the current of each phase, and compare with the set value. When the current is abnormal, the microprocessor sends a signal to make the electronic release drive the operating mechanism to act.
The circuit breaker can close, carry and break the current under normal circuit conditions, and can close, carry and break the current under abnormal circuit conditions within the specified time.