HOUSING 5S8377 - Caterpillar

You must read and understand the warnings and instructions contained in the Safety section of this manual before performing any operation or maintenance procedures.When a generator is in storage, moisture condenses in the windings. To minimize condensation, always put the generator in a dry storage area. If possible, use space heaters to keep generator windings dry during storage.After Storage
After removing the generator from storage, perform an insulation resistance check of the main stator windings. Use a megohmmeter (megger) to preform this check. Compare the resistance reading with the reading made prior to storage. If the readings are lower than specified in the Service Manual, it may be necessary to dry the windings.The insulation resistance check is described in Special Instruction SEHS9124. A reading of one megohm or less indicates that the winding has absorbed too much moisture.To remove moisture caused by high humidity, use one of the following methods to make the generator dry.1. Energize space heaters in generator, if so equipped.2. Put the generator in an oven at a temperature of not more than 85°C (185°F) for four hours.
If an oven is used for drying, use a forced air type rather than a radiant type. Radiant ovens can cause localized overheating.
3. Space heaters of the same type used in marine applications, can be installed on generators. (See the Parts Book.) These heaters heat the windings to remove moisture and should be connected at all times in high humidity conditions whenever the generator is not running.4. Use a canvas enclosure around the generator and heating lamps to increase the temperature. Make an opening in the top for release of moisture.5. Send a low voltage current through the windings to increase the temperature of the windings. Do not exceed 85°C (185°F).If the resistance test reads under one megohm after the drying, or if it goes below one megohm shortly after drying, contact your Caterpillar dealer. The insulation has deteriorated and should be reconditioned.