Can start, the sound is abnormal, the switch trips after running for a while:
1. The grid capacity is insufficient and the voltage is low;
2. The line is leaking;
3. The wiring is unreliable. After running for a period of time, the wire is broken due to heat;
4. The motor wiring is wrong, and the Y connection method is connected to the △ connection method (generally, the motor including 4KW below 4KW is Y connection method, and the connection above 4KW is △ connection method);
5. The high-speed and low-speed wiring connection of the two-speed fan motor is wrong. The control box is not designed and produced according to the principle of △/YY (or Y/YY), which causes the control principle to be wrong.