5 selection principles for low-voltage circuit breakers:

(1) Determine the type of circuit breaker selected according to the load nature, fault category and line protection requirements of the low-voltage power distribution system, and comply with the current relevant national standards.

(2) The rated voltage and frequency of the circuit breaker should be compatible with the nominal voltage and nominal frequency of the circuit.

(3) The rated current of the circuit breaker should not be less than the calculated load current of the circuit.

(4) The circuit breaker should be adapted to the local environment.

(5) The circuit breaker should meet the requirements of dynamic stability and thermal stability during short circuit.