Servo motor ten fault analysis

1, motor encoder alarm
(1) Fault causes
① Wiring error;
② Electromagnetic interference;
③ encoder hardware damage caused by mechanical vibration;
④ Pollution caused by the site environment;

(2) Troubleshooting
① Check the wiring and eliminate errors;
② Check whether the shielding is in place, check whether the wiring is reasonable and solved, and increase the filter to improve it if necessary;
③ Check the mechanical structure and improve it;
④ Check whether the inside of the encoder is polluted, corroded (dust, oil, etc.), and strengthen protection;

(3) Installation and wiring standards
① Try to use the original cable;
② Separate cables so that they are as far away from polluted wiring as possible, especially high-pollution wiring;
③ Always use internal power sources whenever possible. If switching power supplies are used, filters should be used to ensure that the power supply reaches a clean level;
④ Always ground the common end;
⑤ Keep the encoder housing insulated with the machine structure and connected to the cable shielding layer;
⑥ If the encoder cannot be insulated, the cable shield can be connected to the ground (or dedicated terminals) on the encoder housing and driver frame.

2, the motor shaft is broken
(1) Fault causes
① Unreasonable mechanical design leads to excessive radial load;
② The load end is stuck or serious instant overload;
③ The motor and reducer are assembled differently.

(2) Troubleshooting
① Check the maximum radial load that can be borne in the motor sample and improve the mechanical design;
② Check the operation of the load end, confirm the actual process requirements and improve;
(3) Check whether the load is stable, whether there is vibration, and improve the accuracy of mechanical assembly.

3, the motor no-load current is unbalanced, the three-phase difference is large
(1) Fault causes
① the end of the winding is wrong;
② Power supply voltage imbalance;
③ The winding has faults such as inter-turn short circuit and coil reverse connection.

(2) Troubleshooting
① Check and correct;
② Measure the power supply voltage and try to eliminate the imbalance;
③ Eliminate winding faults.

4, the motor running sound is abnormal and abnormal
(1) Fault causes
① bearing wear or oil sand and other foreign matter;
② The rotor core is loose;
③ bearing oil shortage;
④ The power supply voltage is too high or unbalanced.

(2) Troubleshooting
① Replace bearings or clean bearings;
② Repair the rotor core;
③ Come on;
④ Check and adjust the power supply voltage

5, the motor is difficult to start, when the rated load, the motor speed is lower than the rated speed
(1) Fault causes
① The power supply voltage is too low;
(2) misconnection of the face-connected motor;
③ the rotor is welded or broken;
④ The local coil of the rotor is misconnected or reversed;
⑤ the number of turns increased too much when repairing the motor winding;
⑥ Motor overload.

(2) Troubleshooting
① Measure the power supply voltage and try to improve it;
② Corrective connection;
③ Check the opening welding and breakpoints and repair;
④ Find out the wrong connection to correct;
⑤ Restore correct turns;
⑥ Load reduction.

6, after the power can not turn the motor, but no noise, no odor and smoke?
(1) Fault causes
① The power supply is not on (at least two phases are not on);
② fuse is blown (at least two phases are blown);
③ The overcurrent relay is too small;
④ The control device is connected incorrectly.

(2) Troubleshooting
① Check the power circuit switch, fuse, junction box is broken, repair;
② Check the fuse type, the cause of the fuse break, and replace the fuse;
(3) Adjust the setting value of the relay and the motor;
④ Correct the wiring.

7. Motor vibration is large during operation
(1) Fault causes
① bearing clearance is too large due to wear;
② Uneven air gap;
③ rotor unbalance;
④ the rotating shaft is bent;
⑤ The coupling (pulley) coaxial is too low.

(2) Troubleshooting
① Repair bearings and replace them if necessary;
② Adjust the air gap to make it uniform;
③ Correct rotor dynamic balance;
④ Straighten the rotating shaft;
⑤ Recalibrate to make it comply with the regulations.

8, the motor does not turn hum after power
(1) Fault causes
① The rotor winding has a break (a phase break line) or a power supply phase loss;
② The initial end of the winding lead line is connected incorrectly or the winding is reversed;
③ The power loop contact is loose, and the contact resistance is large;
④ the motor load is too large or the rotor is stuck;
⑤ The power supply voltage is too low;
⑥ Small motor assembly is too tight or bearing oil is too strong;
⑦ The bearing is stuck.

(2) Troubleshooting
① Identify the breakpoint and repair 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 the joints are false, and repair them;
④ Reduce the load or detect and eliminate mechanical faults;
⑤ Check whether the specified face connection is misconnected; Whether the voltage drop is too large due to the thin power supply wire, to be corrected;
⑥ Reassembly to make it flexible; Replace qualified grease;
⑦ Repair bearings.

9, bearing overheating?
(1) Fault causes
① Too much or too little grease;
② Poor oil containing impurities;
(3) Improper combination of bearing and journal or end cap (too loose or too tight);
④ the bearing inner hole is eccentric, and the shaft is rubbed;
⑤ Motor end cover or bearing cover is not installed flat;
The coupling between the motor and the load is not corrected, or the belt is too tight;
⑦ bearing clearance is too large or too small;
⑧ The motor shaft is bent.

(2) Troubleshooting
① Add grease according to the regulations (1/3-2/3 of the volume);
② Replace the clean lubricating grease;
③ Too loose can be repaired by binder, too tight should be applied, grinding the inner hole of the journal or end cover to make it suitable;
④ Repair bearing cover to eliminate friction points;
⑤ Reassembly;
⑥ Recalibrate and adjust the belt tension;
⑦ Replace the new bearing;
⑧ Correct motor shaft or replace rotor.

10. Is the motor overheating or even smoking?
(1) Fault causes
① The power supply voltage is too high;
(2) The power supply voltage is too low, the motor runs with rated load, and the current is too hot for the winding;
③ When repairing and removing winding, improper thermal dismantling method is used, which burns the iron core;
④ motor overload or frequent start;
⑤ the motor lacks phase, two-phase operation;
⑥ the coating of the winding is not sufficient after rewinding;
⑦ High ambient temperature motor surface dirt, or blocked ventilation.

(2) Troubleshooting
① Reduce the power supply voltage (such as adjusting the power supply transformer tap);
② Increase the power supply voltage or change the thick power supply wire;
③ Repair the iron core and eliminate the fault;
④ load reduction; Control starting according to the specified number of times;
⑤ Restore three-phase operation;
⑥ Secondary dipping and vacuum dipping process;
⑦ Clean the motor, improve the ambient temperature, and adopt cooling measures.

Source: Industrial control coach