Want to keep your circuits safe? How much do you know about circuit breakers?

Circuit breakers play the role of intelligent guards in protecting circuit safety. 

As the "safety valve" of the power system, it can cut off 50kA fault current within 0.02 seconds, with circuit protection, power distribution, equipment protection and other core functions.

Circuit breakers are classified in a variety of ways.

 According to the voltage level, there are low-voltage circuit breakers (voltage less than 3kV, used for residential/commercial distribution, integrated overload, short circuit, leakage protection functions) and high-voltage circuit breakers (voltage greater than or equal to 3kV, used in substations/transmission and distribution systems, with vacuum arc extinguishing /SF6 gas insulation and other technical characteristics); According to the special function type, there are intelligent circuit breakers (integrated Internet of Things module, support remote control), frame circuit breakers (suitable for industrial high-current scenarios), micro circuit breakers (household distribution box standard configuration) and so on.

Its working principle includes electromagnetic trip (10-12 times the current when the short circuit generates a strong magnetic field to trigger the mechanical trip instantaneously), thermal effect protection (bimetal sheet is heated and bent to push the trip mechanism to respond to overload), electronic monitoring (real-time monitoring of current parameters through the transformer), etc. It also has key technical indicators such as breaking capacity (Icu for extreme breaking, Ics for running breaking), time characteristics (instantaneous protection, short delay, long delay and other different response times).

In terms of intelligent technology innovation, circuit breakers have experienced the intelligent evolution from traditional to electronic to Internet of Things intelligent circuit breakers, and their functions have been upgraded to real-time monitoring of 18 parameters (such as voltage, current, etc.), an early warning system, and remote control. In smart home, industrial Internet of Things, smart city, emergency management and other typical application scenarios have different benefits, such as smart home energy saving 15%-20% and so on.

There are three principles for the purchase of circuit breakers: to identify the CCC mark and IEC/GB standard; The C-type trip curve should be considered for home use, and the motor starting current should be considered for industrial use. When there is a need for expansion, the intelligent type should support communication, and the corresponding version should be selected for special environments. In terms of maintenance, monthly inspection (test leakage protection function, check terminal temperature), annual maintenance (remove contact oxidation layer, verify trip characteristics), troubleshooting when encountering faults (such as frequent tripping, failure to close).

According to the latest market data, the global circuit breaker market is expected to reach $32 billion in 2025, of which the proportion of intelligent products will exceed 45%, and the technology development focuses on digitalization (failure prediction system combined with AI), modularity (plug and play intelligent unit), and environmental protection (new insulating media replacing SF6). In short, the selection of high-quality circuit breakers is very important for the circuit system, and the power system "physical examination" should be carried out regularly.