What is the cause of generator overheating?
1. The generator did not operate according to the specified technical conditions.
If the stator voltage is too high, the iron loss will increase. The load current is too large. The copper loss of stator winding increases. The frequency is too low. Slow down the cooling fan speed. Affect the heat dissipation of generator. The power factor is too low. The excitation current of the rotor is increased. Cause the rotor to heat up. Check whether the indication of the monitoring instrument is normal. If it is abnormal, necessary adjustment and treatment should be carried out. Make the generator operate in accordance with the specified technical conditions.
2. The three-phase load current in the generator set is unbalanced. Overload of one phase winding will overheat.
If the difference of three-phase current exceeds 10% of rated current. It belongs to serious phase current unbalance. The unbalanced three-phase current will produce negative sequence magnetic field. This increases the loss. It causes heating of magnetic pole winding and ferrule. Three phase load should be adjusted. Keep the phase current balance as much as possible.
3. The air duct is blocked by dust and the ventilation is poor, which makes it difficult to heat the generator.
Dust and oil dirt should be removed to make the air duct unobstructed.
4. If the inlet air temperature is too high or the water inlet temperature is too high, the cooler is blocked.
The inlet air or water inlet temperature should be reduced to remove the blockage in the cooler. Before troubleshooting. The generator load should be limited. To reduce the generator temperature.
5. Too much or too little grease is added to the bearing.
Grease should be added as required. It is usually 1 / 2 ~ 1 / 3 of the bearing chamber (the upper limit is taken for the lower speed). The lower limit shall be taken if the speed is high). It should not exceed 70% of the bearing chamber.
6. Bearing wear.
If the wear is not serious, the bearing will be overheated locally. If the wear is serious. It may cause friction between stator and rotor. The stator and rotor avoid overheating. Check the bearing for noise. If friction between stator and rotor is found. Stop the machine immediately for maintenance or replace the bearing.
7. The insulation of stator core is damaged.
It can cause short circuit between chips. As a result, the eddy current loss of the iron core is increased and the heat is generated. When it is serious, the stator winding will be damaged. Stop the machine immediately for maintenance. It can also be sent to the manufacturer of generator set for maintenance.