Mitsubishi Electric JR Series Instruction Manual page 26

Phenomenon
1. The belt disconnects.
2. The protection device
functions.
The relay trips.
The fuse is blown.
3. The switch overheats.
4. The motor overheats.
5. The speed drops.
The speed does not
increase.
The acceleration is slow.
The motor does not
rotate.
6. The temperature rises
abnormally during load
operation.
7. The bearings overheat.
8. An abnormal noise is
heard.
Groaning noise.
Moving noise.
9. The vibration is great.
10. The ammeter sways.
Cause
1. Overload.
2. The partner machine is faulty and belt
does not rotate.
3. The belt tension is incorrect.
1. The partner machine is faulty.
2. The relay or fuse selection is
incorrect.
3. The usage conditions are incorrect.
Usage time, frequency.
4. Overload.
5. The power is faulty.
1. The switch selection is incorrect.
2. The switch contact is faulty.
1. The stator winding is faulty.
2. Overload.
3. The power is faulty.
4. The usage conditions are incorrect.
1. The power is faulty.
2. The rotor is faulty.
3. Overload.
1. The power is faulty.
2. The cooling ventilation is blocked.
3. The ambient temperature is too high.
4. Overload.
5. The stator winding is faulty.
1. The shaft center is off.
2. The bearings are defective.
3. Over grease.
4. The belt is too tense.
5. The grease has deteriorated, is
insufficient, or the quality is poor.
1. The power is faulty.
2. The ventilation path is blocked.
3. Overload.
4. The bearings are defective.
5. The grease is poor.
6. The rotor is faulty.
7. The rotor's iron core is contacting the
stator's iron core.
8. The rotation section is contacting the
stator or outer sheath.
9. The installation of parts such as the
bracket or fan is faulty.
10. The bracket engagement is worn.
(Load rotation unbalance is large,
vibration is large.)
1. The coupling alignment is incorrect.
2. The coupling is faulty.
3. The machine side is unbalanced.
4. Impact is conveyed from machine
side.
1. The power is faulty.
2. The load varies.
3. The belt tension is incorrect.
4. Cyclic swaying with groan, the stator
or rotor is faulty.
- 21 -
Remedy
1. Reselect the motor rating.
2. Inspect and repair the partner
machine.
3. Set the belt again.
1. Adjust the partner machine.
2. Replace the relay or fuse.
3. Review the usage conditions.
4. Reselect the motor rating.
5. Improve the power facility.
1. Reselect the switch.
2. Adjust the switch.
1. Have specialist repair.
2. Reselect the motor rating.
3. Improve the power facility.
4. Review the usage conditions.
1. Improve the power facility.
2. Replace the rotor.
3. Reselect the motor rating.
1. Improve the power facility.
2. Improve the cooling ventilation.
(Remove dirt, etc.)
3. Improve the ambient environment.
4. Reselect the motor rating.
5. Have specialist repair.
1. Center the shaft.
2. Replace the bearings.
3. Adjust the grease amount.
4. Adjust the belt tension.
5. Replenish or replace the grease.
1. Improve the power facility.
2. Remove the obstacle.
3. Reselect the motor rating.
4. Replace the bearings.
5. Replenish or replace the grease.
6. Replace the rotor.
7. Have specialist repair.
8. Have specialist repair.
9. Retighten or adjust.
10. Correct the balance, reduce the
vibration, replace the bracket and
bearings.
1. Recouple.
When recentering and coupling
consider the thermal expansion
margin.
2. Inspect and adjust the coupling.
3. Review the machine side balance.
4. Inspect the machine side.
1. Improve the power facility.
2. Adjust the load.
3. Adjust the belt tension.
4. Inspect and repair the stator and rotor.