The motor does not turn and there is a buzzing sound after power on
1. Causes of failure ① The rotor winding is broken (one phase is disconnected) or the power supply is lost in one phase; ② The beginning and end of the winding lead wire are connected incorrectly or the internal winding is reversed; ③ The power circuit contact is loose and the contact resistance is large; Large or the rotor is stuck; ⑤ The power supply voltage is too low; ⑥ The assembly of the small motor is too tight or the grease in the bearing is too hard; ⑦ The bearing is stuck.
2. Trouble shooting ① Identify the breakpoint and fix it; ② Check the polarity of the winding; determine whether the end of the winding is correct; ③ Tighten the loose wiring screws, use a multimeter to determine whether each joint is falsely connected, and repair it; And eliminate mechanical failures, ⑤ check whether the specified surface connection is mistakenly connected; if the power supply wire is too thin and the voltage drop is too large, correct it, ⑥ reassemble to make it flexible; replace qualified grease; ⑦ repair the bearing.