SPRING-GUIDE 1W2473 - Caterpillar

Generator Set AllIntroduction
Winding insulation breakdown in generators causes current leakage and lower high voltage resistance, which allows short circuit condition to occur. Generators stored in or operated in contaminated environments are especially at risk. Environment contaminants include excess dust, water, salt, grease, and humidity and should not be allowed to accumulate on the generator windings. This Special Instruction provides information for testing and maintenance procedures.Reference: Refer to the following documents for more information:
"IEEE STD 43-2000 Recommended Practice for Insulation Testing of Rotating AC Machinery"
Engine News, SEBD0660, "Operating Environment and Effects on SR4 Generators"
Application and Installation Guide, LEBW4993, "Generator Systems"
Application and Installation Guide, LEBE5294, "EP Applications, Engine & Generator Sizing"Important Safety Information
Work safely. Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools in order to perform these functions properly. Safety precautions and warnings are provided in this instruction and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. Therefore, the warnings in this publication and the warnings that are on the product are not all inclusive. If a tool, procedure, work method, or operating technique not recommended by Caterpillar is used: Ensure that such tool, procedure, work method, or operating technique are safe for you and for other people to use. Ensure that the product will not be damaged, or be made unsafe, by the operation, lubrication, maintenance, or repair procedures that are used.
Personal injury or death can result from high voltage.When power generation equipment must be in operation to make tests and/or adjustments, high voltage and current are present.Improper test equipment can 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.When servicing or repairing electric power generation equipment:
Make sure the unit is off-line (disconnected from utility and/or other generators power service) , and either locked out or tagged DO NOT OPERATE.
Remove all fuses.
Make sure the generator engine is stopped.
Make sure all batteries are disconnected.
Make sure all capacitors are discharged.Failure to do so could result in personal injury or death. Make sure residual voltage in the rotor, stator and the generator is discharged.
Personal injury or death can result from a spark.An incompletely discharged capacitor can cause a spark.Do not use the insulation tester in an explosive atmosphere.
Personal injury or death can result from electrocution.The megohmmeter is applying a high voltage to the circuit.To avoid electrocution, do not touch the instrument leads without first discharging them. When finished testing also discharge the generator windings.
Personal injury or death can result from the engine starting.Regardless of the cleaning method used; to avoid