General Conditions for Selection of Low Voltage Apparatus:1. The rated current of electrical equipment shall be greater than the calculated current of the circuit in which it is located;2. The rated frequency of electrical equipment shall be adapted to the nominal frequency value of the circuit in which it is located;3. The rated voltage of electrical equipment shall be adapted to the nominal voltage value of the circuit where it is located;4. Electrical equipment used to disconnect short-circuit current shall have sufficient breaking capacity under short-circuit conditions.