LATCH AS 3401299 - Caterpillar

Attach a "DO NOT OPERATE" or similar warning tag to start switch or controls before performing any service or repairs.
"DO NOT OPERATE" tags are available from Caterpillar. Order Form SEHS7332.
When power generation equipment must be in operation to make tests and/or adjustments, high voltage and current are present.
* Improper test equipment may fail and present a high voltage shock hazard to its user.* Make sure the testing equipment is designed for and correctly operated for high voltage and current tests being made.
New Equipment
Storage
After a new generator arrives on site it should be protected against moisture until it is installed.
When a generator is in storage, moisture condenses in the windings. To minimize condensation, always put the generator in a dry storage area.
When the generator is placed in storage, it is necessary that a megger insulation resistance check be performed and the results recorded. The temperature and level of humidity should also be recorded. This check will provide a baseline for future reference.
It is important that this baseline be established when the unit is dry.To guard against collective contaminants, the generator should be covered with a plastic cover or similar type of protective cloth. The protective cover should extend to the ground, but remain loose around the generator in order to allow it to properly breathe.
Caterpillar recommends maintaining the insulated parts and the air surrounding them at a temperature of at least 5° C (9°F) higher than the room temperature in which the equipment is located. This will prevent condensation. Normal methods of providing the heat required are:
1. Space heaters.2. Warm air blower. Do Not exceed 206.7 kPa (30 psi).3. Light bulb (60 Watt minimum) installed inside the generator in proximity to the stator core at the lowest possible location.It is important that the shaft be rotated 10 revolutions every 60 days throughout the storage period. This process helps to insure that grease continues to cover all bearing surfaces.
Removal From Storage
Operate space heaters for at least 24 hours prior to removing covers.
Before startup of a generator, visually inspect the generator for any foreign material such as rodents, etc. that may have nested in the generator. Use a megohmeter to check insulation resistance for moisture and/or foreign material. Refer to the Service Manual for the procedure.
A resistance reading with a 50% reduction from the reading recorded when the unit was placed in storage (100 megohms for a new unit), is an indication that the winding has absorbed too much moisture. Clean as necessary according to the instructions in Special Instruction, SEHS9124, "Cleaning and Drying of Electric Set Generators".
Visual Equipment Checks
The generator should be checked periodically for any accumulation of dust, water, salt, grease, or oil films. Clean as necessary according to the instructions in Special Instruction, SEHS9124, "Cleaning and Drying of Electric Set Generators".
Windings must be kept clean and dry. Any accumulation of dirt will trap moisture. This moisture will reduce the insulation's dielectric strength, causing the insulation to fail.Recommended Megger Insulation Test Procedure
Main Stator
1. Take generator out of service.2. Visually