RING-PISTON 9L6934 - Caterpillar

Note: Read the warnings and read the instructions that are contained in the Safety Section of this manual. These warnings and instructions must be understood before you perform any operation or any maintenance procedures. Rotating electric machines are complex structures that are exposed to the following forms of stress:
mechanical
electrical
thermal
environmentalThese stresses may be of varying magnitudes. The insulation systems are very susceptible to damage that is caused by the stresses that are listed above. Exposure to these stresses may shorten the effective life of the insulation system. Therefore, the service life of an electric machine will largely depend on the serviceability of the insulation systems. An inspection program and a testing procedure are recommended. An inspection program and a testing procedure will ensure that the equipment is maintained in satisfactory condition. This will increase field reliability.A regular maintenance and inspection program can provide an evaluation of the present condition of the equipment. A regular maintenance program and a regular inspection program can also reveal future problems. The frequency of this maintenance program will depend on the following factors:
application
environmental conditions
operator's experience
operator's philosophyA regular maintenance program is strongly recommended. This program would involve the following steps:
periodic disassembly
knowledgeable visual examination of the equipment
the application of electrical testsNever perform a test over the rated potential. These tests can damage insulation that is contaminated or insulation that is in marginal condition. For more information, refer to "I.E.E.E. Standard 432-1992" or consult a Caterpillar dealer. Space Heaters
The SR4 HV and SR4B HV generators are capable of operating in high humidity conditions without problems. However, problems can occur when the generator is idle and the surrounding air is warmer than the generator. Moisture can form on the windings that will result in poor performance from the windings. Moisture can also result in damage to the windings. Whenever the generator is not active, ensure that the space heaters are in operation. Whenever the generator is operating, ensure that the space heaters are disconnected. An external source of either 115 VAC or 230 VAC is required to operate the space heaters.
Illustration 1 g00556903
Space Heater Connection to External Source (H1), (H2), (H3) and (H4) Terminals.
If a 115 VAC source is available, connect both heaters in parallel across the source. If a 230 VAC source is available, connect both heaters in series across the source. Refer to Illustration 1.Field Conditions that Reduce Insulation Life
Electric machines and associated insulation systems are exposed to the following types of stress: mechanical, electrical, thermal and environmental. These stresses produce many deteriorating influences. The following list defines the most significant influences. Thermal Aging - This is the deteriorating influence on insulation that is caused by the normal service temperature.Overtemperature - This is the unusually high temperature of operation that is caused by the following conditions: overload, high ambient temperature, restricted ventilation, winding faults and foreign materials that are deposited on windings.Overvoltage - This is a voltage that is much higher than the rated nameplate voltage. This voltage can be caused by switching surges or lightening