|Failure||Cause of failure||Troubleshooting|
|1. The electric motor doesn't rotate after being electrified. But there is no abnormal sound, peculiar smell and smoke.|| ① No electricity (at least two phase); |
② Fuse failure (at least two phase);
③ The debugging of the servo motor is not completed;
④ Wiring error of the control unit.
| ① Check and repair the break point at the rotary switch of the power supply, fuse and junction box; |
② Check the type of fuse, and the reason of fuse failure; change a new fuse;
③ Adjust the matching of the actuator and electric motor, adjust the parameters of the actuator;
④ Correct the wiring.
|2. The electric motor doesn't rotate after being electrified. And there is drone of the engine.|| ① The power of one phase is cut off or failed; |
② The terminal of winding outgoing line is connected in a wrong way or the internal of winding is reversely connected;
③ The contact of supply circuit is loose, so that the contact resistance is big;
④ The load of the electric motor is too big; or the rotor is stuck;
⑤ The supply voltage is too low;
⑥ The assembly of small electric motor is too tight; or the lubricating oil in the bearing is too hard;
⑦ The bearing is stuck.
| ① Check and repair the break point; |
② Check the polarity of the winding;
③ judge that if the winding terminal is correct;
④ Tighten the loose connection screws; check and repair the misconnection of the terminals of the winding by using multi-meter;
⑤ Load shedding or checking and removing the mechanical failure;
⑥ Check and correct misconnection; and if the power supply wire is too thin thus causing too large pressure drop;
⑦ Reassemble the electric motor and change the lubricating oil of the bearing;
⑧ Repair the bearing.
|3. It is difficult to start up the electric motor. The speed of the electric motor is significantly lower than the rated speed when the motor is running with rated load.|| ① The supply voltage is too low; |
② The connection of the electric motor is wrong;
③ Open welding or crack of the rotor;
④ Part of the coil of stator is misconnected or reversely connected;
⑤ The number of windings added during the repairment of the motor winding is too much;
⑥ The motor is overloaded.
| ① Measure the supply voltage and then improve the condition; |
② Correct the connection;
③ Check and repair the open welding and breaking point;
④ Check and correct the misconnection;
⑤ Restore the correct number of windings;
⑥ Load shedding.
|4. There is no-load current unbalance of the electric motor. There is big difference among three phases.|| ① Misconnection of two ends of the winding; |
② Supply voltage unbalance;
② Turn-to-turn short circuit, reverse connection of coil and some other winding failure.
| ① Check and correct the connection of two ends of the winding; |
② Measure the supply voltage, and try to eliminate unbalance;
③ Eliminate winding failure.
|5. The running sound of the electric motor is abnormal.|| ① Beating abrasion or sand or impurities in the lubricating oil; |
② The bearing is lack of lubricating oil;
③ Too high supply voltage or supply voltage unbalance.
| ① Change or clean the bearing; |
② Check and repair the iron core of the rotor;
③ Add lubricating oil;
④ Check and adjust the supply voltage.
|6. The vibration of the running electric motor is quite violent.|| ① The big gap caused by the bearing abrasion; |
② Uneven air gap;
④ Rotor unbalance;
⑤ Rotating shaft bending;
⑥ Coaxiality of the coupling (belt pulley) is too low.
| ① Check and repair the bearing or change when necessary; |
③ Bearing correction;
④ Correct again so that it can meet the standard.
|7. Overheated bearing.|| ① The lubricating oil is too much or too little; |
② There are impurities in the lubricating oil;
③ The bearing and the shaft neck or end cover is not matching (too loose or too tight);
④ The inner bore of the bearing is off center, so there is friction between the bore and shaft; ⑤ The motor end cover and the shaft cover is not flat;
⑥ The motor and the loaded coupling is not corrected, or the belt is too tight;
⑦ The bearing clearance is too large or too small;
⑧ The electric motor shaft bending.
| ① Add lubricating oil according to the regulation (solvent 1/3-2/3); |
② Change into the clean lubricating oil; ③ If it is too loose, you can repair it with binder; if it is too tight, you can make it suitable by grinding the shaft neck or inner bore of the end cover;
④ Change the bearing;
⑤ Assemble again;
⑥ Correct again, adjust the belt tension;
⑦ Change into a new bearing;
⑧ Motor shaft correction or rotor replacement.
|8. Overheated or even smoking electric motor.|| ① The supply voltage is too high; |
② The supply voltage is too low, the electric motor operates with rated load, too large electric current will cause the heat of winding;
③ The heat removing method which is used to repair and remove the winding is not proper, so the iron core is burnt down;
④ The motor is overloaded or started up too frequently;
⑤ Lack of phase, operate with only two phases;
⑥ After the rewinding, the impregnation of stator winding is insufficient;
⑦ High environment temperature, lot of dirt on the surface of the electric motor or blocking of air shaft.
| ① Reduce the supply voltage (such as adjusting the tapping point of the supply transformer); |
② Increase supply voltage or adopt thicker supply conductor;
③ Check the iron core for troubleshooting;
④ Load shedding; control the start-up times within the specified number of times;
⑤ Restore 3 phase operation;
⑥ Adopt secondary impregnation and vacuum impregnation;
⑦ Clean the motor, improve environment temperature by adopting cooling measure.