The motor cannot rotate after being energized, but there is no abnormal noise, odor and smoke.
1. Causes of failure ① The power supply is not connected (at least two phases are not connected); ② The fuse is blown (at least two phases are fused); ③ The overcurrent relay is adjusted too small; ④ The wiring of the control equipment is wrong.
2. Trouble shooting ① Check the power circuit switch, whether there is a breakpoint at the fuse and junction box, repair; ② Check the fuse type, the reason for the fuse, and replace with a new fuse; ③ Adjust the relay setting value to match the motor; ④ Correct the wiring.