1: The power supply is dead or the switch is not closed;
2: the power supply is not connected;
3: the control box is loose and has poor contact due to transportation vibration;
4: the coil of AC contactor has been burnt out.
5: wait for an incoming call or turn on the power switch;
6: check the control box with an electric meter or pen. If there is no power, turn on the power supply;
7: check all wiring points of the control box and fasten them with a screwdriver;
8: check the contactor coil with the "Ω" gear of the electric meter and repair or replace it.
9: one phase of the power supply is open circuit;
10: one phase of CJ main contact is burnt out;
