How to deal with the damp diesel generator set?
2021-12-24
How to deal with the damp diesel generator set? Today, Raines answers:
1. Hot air method
Remove all cover plates of the generator set to facilitate the escape of humid air. Use an electric hair dryer to blow inward from the air inlet of the generator set. Note that at least 300mm shall be kept between the heat source and the winding to avoid insulation damage caused by overheating. Control the winding surface temperature, and measure the winding surface with thermometer, which shall not exceed 85 ℃, and the air inlet shall not exceed 90 ℃. Keep blowing and record the insulation resistance value every half an hour. When the value is greater than the specified value, the drying process has been completed. Remove the hair dryer, cover all covers, and then try again.
2、 Cold operation method
The generator set placed in dusty and humid environment for a long time can run idle for about 10 minutes with the AVR power conductor disconnected, which may be enough to dry the winding surface and increase the insulation resistance to more than 1 megohm, so that the generator set can resume normal operation.
3、 Short circuit current drying method
Firstly, carry out the safe operation of machinery and electrical appliances of the unit to ensure the operation safety on the generator unit. The output end of the generator set shall be short circuited through the short-circuit strip, and the short-circuit strip used shall be able to bear the rated current of the generator set. Disconnect the AVR, switch to external 0 ~ 24V DC power supply, adjust the DC power supply voltage so that each phase current of the stator is 50-70% of the rated current, shut down every 30 minutes, disconnect the external excitation power supply, detect and record the insulation resistance value. If the insulation resistance value is greater than the specified value, remove the external DC power supply, reconnect the AVR and re test run. The generator set may not operate at the rated speed, but the speed shall be kept constant to avoid temperature instability.
4、 Load drying method
If only the surface is wet, it can be dried by load drying method. When dry, the generator set can operate with 50% rated current load first. Then increase the value of 65%, 85% and 100% to the rated current, run each level of load for 4 ~ 5 hours, and regularly detect the insulation resistance of each winding during drying. After the insulation resistance value meets the requirements, the drying can be stopped, and the generator set can be put into normal trial operation.
1. Hot air method
Remove all cover plates of the generator set to facilitate the escape of humid air. Use an electric hair dryer to blow inward from the air inlet of the generator set. Note that at least 300mm shall be kept between the heat source and the winding to avoid insulation damage caused by overheating. Control the winding surface temperature, and measure the winding surface with thermometer, which shall not exceed 85 ℃, and the air inlet shall not exceed 90 ℃. Keep blowing and record the insulation resistance value every half an hour. When the value is greater than the specified value, the drying process has been completed. Remove the hair dryer, cover all covers, and then try again.
2、 Cold operation method
The generator set placed in dusty and humid environment for a long time can run idle for about 10 minutes with the AVR power conductor disconnected, which may be enough to dry the winding surface and increase the insulation resistance to more than 1 megohm, so that the generator set can resume normal operation.
3、 Short circuit current drying method
Firstly, carry out the safe operation of machinery and electrical appliances of the unit to ensure the operation safety on the generator unit. The output end of the generator set shall be short circuited through the short-circuit strip, and the short-circuit strip used shall be able to bear the rated current of the generator set. Disconnect the AVR, switch to external 0 ~ 24V DC power supply, adjust the DC power supply voltage so that each phase current of the stator is 50-70% of the rated current, shut down every 30 minutes, disconnect the external excitation power supply, detect and record the insulation resistance value. If the insulation resistance value is greater than the specified value, remove the external DC power supply, reconnect the AVR and re test run. The generator set may not operate at the rated speed, but the speed shall be kept constant to avoid temperature instability.
4、 Load drying method
If only the surface is wet, it can be dried by load drying method. When dry, the generator set can operate with 50% rated current load first. Then increase the value of 65%, 85% and 100% to the rated current, run each level of load for 4 ~ 5 hours, and regularly detect the insulation resistance of each winding during drying. After the insulation resistance value meets the requirements, the drying can be stopped, and the generator set can be put into normal trial operation.