ADAPTER 4N9935 - Caterpillar

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 surges. Operating above the rated nameplate voltage will reduce the life of the insulation.Contamination - Contamination deteriorates electrical insulation in the following ways:
conducting current over insulated surfaces
attacking the material and reducing the quality of the material's electrical insulation
attacking the material and reducing the material's physical strength
creating a thermal insulation that causes the material to operate at higher than normal temperaturesSome potential contaminants are listed below:
water or extreme humidity
unstable antiwear oil or grease
oil or grease that contains extreme pressure additives
conductive dust and conductive particles
nonconductive dust and nonconductive particles
industrial chemicals such as acids, solvents, and cleaning solutionsPhysical Damage - This contributes to the failure of electrical insulation by opening a conductive path through the insulation. The following list includes some of the physical damages that can occur:
physical shock
vibration
overspeed
erosion by foreign matter
damage by foreign objects
thermal cyclingIonization Effects - Ionization (corona) can occur at higher operating voltages. Ionization is accompanied by several undesirable effects such as chemical action, heating, and erosion.