IMPELLER 2820683 - Caterpillar

Do not operate the generator if the windings are wet. If the generator is operated when the windings are wet, damage can occur due to insulation breakdown.
When moisture is present or when moisture is suspected in a generator, the generator must be dried before being energized.If the drying procedure does not restore the insulation resistance to an acceptable value, the winding should be reconditioned.Note: For additional information, refer to Special Instruction, SEHS9124 .Drying Methods
The following methods can be used for drying a generator:
Self-circulating air method
Oven method
Do not allow the winding temperature to exceed 85 °C (185.0 °F). Temperatures that are greater than 85 °C (185.0 °F) will damage the winding insulation.
Self-Circulating Air Method
Note: Disable the excitation before using this method.Run the engine and disconnect the generator load. This will help circulate air. Operate the generator space heaters.Oven Method
Place the entire generator inside a forced air drying oven for four hours at 65 °C (149 °F).
Use a forced air type oven rather than a radiant type oven.Radiant type ovens can cause localized overheating.