Guidelines For Selecting Small Circuit Breaker Models

When selecting models for small circuit breakers, several guidelines must be followed:
1. The rated voltage of a small circuit breaker should be higher than the normal operating voltage in the circuit
Even though the working voltage in the circuit usually does not reach the rated voltage of the small circuit breaker, in some circuit faults such as short circuits, overloads, etc., the working voltage of the circuit may exceed the rated voltage of the small circuit breaker. At this time, the high rated voltage of the circuit can cause the insulation effect of the small circuit breaker to decrease, seriously affecting its service life. Therefore, in order to prevent the increase of external leakage current, there are safety hazards. Remember this when choosing the model of a small circuit breaker!

2. The on/off current (standard value of the operating current) of a small circuit breaker should be higher than the maximum short-circuit current generated in the circuit
We should know that when a short circuit occurs in a circuit, the short-circuit current generated is very large. The closer the circuit is to the power source, the greater the short-circuit current will be. This is equivalent to 0 for the resistance of the circuit. Therefore, there must be a high standard for the on/off performance of small circuit breakers. When the on/off current of the small circuit breaker exceeds the maximum current value that may occur when a short circuit occurs in the circuit, the small circuit breaker can instantly activate the release to drive the switch of the small circuit breaker to disconnect the circuit and extinguish the arc when the short circuit current passes through it. On the contrary, if it is less than the maximum short-circuit current, it will cause the arc to burn and bond the contacts of the small circuit breaker together, making it impossible for the small circuit breaker to open and close normally.