11 reasons and troubleshooting methods of dry goods motor failure

2020-12-29 10:23:19

When the motor is running, the sound is abnormal

1. The cause of the problem

(1) the rotor and the stator insulating paper or groove wedge rub;

(2) bearing wear or foreign bodies such as sand in the oil;

(3) rotor core loose;

④ bearing lack of oil;

(5) air duct packing or fan wipe hood;

The stator and rotor core rub;

The power supply voltage is too high or unbalanced;

The stator winding is misconnected or short circuit.

2. troubleshooting

(1) trim insulation, cutting low groove wedge;

② replace the bearing or clean the bearing;

(3) overhaul the stator and rotor core;

(4) come on;

⑤ clean up the air duct; Reinstall;

⑥ eliminate scratches, if necessary, the small rotor inside the car;

Check and adjust the power supply voltage;

Eliminate stator winding faults.

The motor vibrates greatly in operation

1. The cause of the problem

(1) due to wear bearing clearance is too large;

(2) Uneven air gap;

③ Rotor imbalance;

(4) bending of the rotating shaft;

⑤ iron core deformation or loosening;

The coupling (pulley) center is not corrected;

The fan is unbalanced;

The shell or foundation strength is not enough;

⑨ Loose anchor screw of the motor;

Attending cage rotor open welding circuit; Winding rotor circuit break; Add stator winding failure.

2. troubleshooting

(1) overhaul bearings and replace them if necessary;

Adjust the air gap to make it uniform;

(3) Correcting rotor dynamic balance;

(4) alignment axis;

⑤ correction of overlapping cores;

⑥ recalibrate it to meet the requirements;

⑦ Overhaul the fan, correct the balance and correct its geometric shape;

⑧ to reinforce;

⑨ Fasten the foundation screw;

Attending to repair the rotor winding; Repair stator windings.

After electrifying the motor can not rotate, but no noise, no smell and smoke

1. The cause of the problem

The power supply is not connected (at least two phases are not connected);

(2) fuse (at least two phase fuse);

③ the overcurrent relay is too small;

The wiring of the control equipment is wrong.

2. troubleshooting

(1) Check the power loop switch, fuse and junction box for breakpoints, and repair them;

(2) check the fuse model, fuse reason, change the fuse;

(3) adjust the setting value of the relay with the motor;

④ Correct wiring.

The motor will not turn when the power is turned on, and then the fuse will burn out

1. The cause of the problem

(1) lack of a phase power supply, or set the trunk ring a reverse connection;

(2) stator windings interphase short circuit;

③ grounding of stator winding;

(4) Wrong connection of stator winding;

The fuse cross section is too small;

The power line short circuit or ground.

2. troubleshooting

(1) check whether there is a phase is not closed, the power supply loop has a phase broken line; Eliminate reverse connection fault;

(2) find out the short circuit point, to repair;

(3) eliminate grounding;

(4) find out the wrong connection, be corrected;

⑤ replace the fuse;

⑥ Eliminate pickup points.

The motor hums without turning on the power

1. The cause of the problem

(1) The stator and rotor windings are broken (one phase is broken) or the power supply is lost in one phase;

(2) the beginning and end of the winding lead wire is connected wrong or the inner winding is connected wrong;

(3) the contact of the power loop 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 grease is excellent;

⑦ The bearing is stuck.

2. troubleshooting

(1) identify the breakpoint and repair it;

Check the polarity of the winding; Judge whether the winding end is correct;

(3) tighten the loose wiring screw, use a multimeter to determine whether the joints are false, to repair;

(4) load reduction or detection and elimination of mechanical failure;

(5) check is also specified Δ connection misconnection Y; Whether the voltage drop is too large because the power supply wire is too thin, to be corrected;

⑥ reassembly to make it flexible; Replace qualified grease;

⑦ Repair bearings.

The no-load current of the motor is unbalanced and the three terms differ greatly

1. The cause of the problem

(1) When rewinding, the number of turns of the stator three-phase winding is not equal;

(2) wrong connection of winding head and tail;

③ power supply voltage imbalance;

④ The winding has interturn short circuit, coil reverse connection and other faults.

2. troubleshooting

(1) rewind the formulation of the sub-winding;

② check and correct;

(3) measure the power supply voltage and try to eliminate the imbalance;

④ the winding failure.

When the motor is under no load, the pointer of the ammeter swings unsteadily

1. The cause of the problem

(1) open welding or broken guide bars of cage rotor;

(2) winding rotor fault (one-phase circuit break) or brush, collector ring short circuit device contact is poor.

2. troubleshooting

(1) found the broken bar to repair or replace the rotor;

② Check the loop around the rotor and repair it.

The no-load current of the motor is balanced, but the value is large

1. The cause of the problem

(1) When repairing, the number of turns of stator winding is reduced too much;

② the power supply voltage is too high;

(3) Y after motor misconnection Δ;

④ In the motor assembly, the rotor is installed in reverse, so that the stator core is not aligned, and the effective length is shortened;

⑤ The air gap is too large or uneven;

⑥ When dismantling the old windings, the use of thermal disassembly method is improper, so that the core burned.

2. troubleshooting

(1) rewind the stator winding to restore the correct number of turns;

(2) try to restore the rated voltage;

(3) change to Y;

(4) reassembly;

⑤ replace the new rotor or adjust the air gap;

⑥ overhaul the iron core or recalculate the winding, increase the number of turns appropriately.

Difficulty in motor starting Rated load when the speed is lower than the rated more

1. The cause of the problem

The power supply voltage is too low;

(2) Δ connection motor misconnection Y;

(3) open welding or fracture of cage rotor;

(4) the local coil of the stator rotor is misconnected and reversed;

(5) excessive increase of turns when repairing motor windings;

⑥ Motor overload.

2. troubleshooting

(1) measure the power supply voltage and try to improve it;

(2) correct connection method;

Check open welding and break point and repair;

(4) find out the wrong joints and correct them;

⑤ Restore the correct number of turns;

6. Lightening.

The motor overheated and even smoked

1. The cause of the problem

(1) the power supply voltage is too high, so that the core heating greatly increased;

(2) the power supply voltage is too low, the motor is running with rated load, and the current is too high.

(3) when repairing and dismantling windings, improper thermal disassembly method is used, and the iron core is burned;

(4) the stator and rotor core rub;

⑤ Motor overload or frequent starting;

⑥ cage rotor broken bar;

The motor is lack of phase, two-phase operation;

The rewinding is due to the winding immersion paint is not sufficient;

⑨ There is more dirt on the surface of the motor at high ambient temperature, or the ventilation duct is blocked;

Attenuating motor fan failure, poor ventilation; Stator winding fault (short circuit between phases and turns; Internal connection error of stator winding).

2. troubleshooting

To reduce the power supply voltage (e.g., adjust the power supply transformer tap), if the motor Y, Δ connection errors, you should correct connection;

(2) improve the power supply voltage or change the coarse power supply conductor;

(3) overhaul the iron core, troubleshooting;

(4) eliminate the rub point (adjust the air gap or file, car rotor);

5. Lightening; According to the specified number of control starting;

Check and eliminate rotor winding failure;

Restore three-phase operation;

The use of secondary immersion and vacuum immersion process;

⑨ Clean the motor, improve the ambient temperature, adopt cooling measures;

Attending to check and repair fans and replace them if necessary; Overhaul the stator winding and eliminate the fault.

Motor bearing overheating

1. The cause of the problem

(1) too much or too little grease;

② the oil quality is not good and contains impurities;

③ Improper match between bearing and journal or end cover (too loose or too tight)

The inner hole of the bearing is eccentric and rubbed with the shaft;

⑤ motor end cover or bearing cover is not installed flat;

⑥ motor and load coupling is not corrected, or the belt is too tight;

The bearing clearance is too large or too small;

The motor shaft bending.

2. troubleshooting

(1) Add grease according to the provisions (1/3-2/3 of the volume);

② replace the clean lubricating grease;

(3) too loose available binder repair, too tight should be car, grinding shaft journal or end cover hole, make it suitable;

(4) repair bearing cover, eliminate rub points;

⑤ reassemble;

⑥ recalibrate, adjust the belt tension;

⑦ Replace new bearings;

Correct the motor shaft or replace the rotor.