Analysis of Trip Causes and Selection of Miniature Intelligent Circuit Breakers During Use

In daily life, circuit breakers are a crucial electrical device and one of the most important safety devices in commercial and household circuits. Once the current flow in the wiring of a house exceeds a certain limit, this simple circuit device will cut off the power supply until the fault is resolved. Since the reform and opening up, the domestic appliance industry in our country has developed rapidly, with increasing production and types, greatly meeting and enriching the needs of the vast number of consumers. Circuit breakers have been widely used in various feeder lines of low-voltage power distribution systems, as well as the power control and protection of various mechanical equipment and the control and protection of electrical terminals. Such situations where electrical appliances should not be powered off or electrical equipment should not be disconnected unnecessarily occur from time to time during the use of circuit breakers, reducing power supply reliability and causing certain economic losses. The following figure is the structure diagram of the C45 type circuit breaker. Currently, it still occupies a large market share, while the C65 structure and L7 structure are also gradually becoming popular in the market.
A miniature circuit breaker is a type of switchgear that can not only connect and disconnect normal load current and overcurrent, but also connect and disconnect short-circuit current. Although there are many types of circuit breakers, their basic structure and working principle are basically the same. For the double metal sheet in a circuit breaker, when there is an overload current, the force that pushes the breaking contacts is very important. When an overload current occurs in the circuit, when the double metal sheet heats up and deforms to a certain extent, it will push the pull rod, causing the operation mechanism to be driven, and the contacts will break. When the instantaneous current during a short circuit reaches several tens of times the rated current, the electromagnetic trip unit of the circuit breaker will quickly act, push the pull rod, causing the operation mechanism to be driven, and the contacts will break. The tripping of the small-sized circuit breaker seen in daily life is basically caused by the heating and bending of the double metal sheet to trigger the tripping of the circuit breaker.