GUIDE-VALVE 1442904 - Caterpillar

Introduction
When servicing or repairing electric power generation equipment, do the following:a. Make sure the unit is off-line (disconnected from utility power service and/or other generators), and either locked out or tagged DO NOT OPERATE.b. Make sure the generator engine is stopped.c. Make sure all batteries are disconnected.d. Make sure all capacitors are discharged.When power generation equipment must be in operation to make tests and/or adjustments, high voltage and current are present. Make sure the testing equipment is designed for and correctly operated for the high voltage and current tests. Improper test equipment may fail and present a high voltage shock hazard to its user.
Do NOT connect generator to a utility electrical distribution system, unless it is isolated from the system. Electrical feedback into the distribution system can occur and could cause personal injury or death.Open and secure the main distribution system switch or, if the connection is permanent, install a double throw transfer switch to prevent electrical feedback. Some generators are specifically approved by a utility to run in parallel with the distribution system and isolation may not be required. Always check with the utility as to the applicable circumstances.
Test Equipment
Digital Multimeter
6V-7070 Caterpillar Digital MultimeterCaterpillar Digital Multimeters can be used to measure voltage, resistance or current up to 10 amps. Rectifiers can also be checked by using the diode function. See Special Instruction SEHS7734 for the correct operation of the 6V-7070.Clamp-On Ammeter
8T-0900 AC/DC Clamp-On AmmeterThe 8T-0900 Digital Ammeter may be used to measure current up to 1200 amps. When measuring line current on multiple lead units, measure the current in each conductor per phase and add the currents together. See Special Instruction SEHS8420 for the correct operation of the 8T-0900.Troubleshooting
The more common generator system malfunctions, causes of the malfunctions and appropriate repair procedures are listed in the troubleshooting chart that follows.Incorrect electrical connections between the generator system and the regulator and poor electrical connections are often the cause of system malfunction. Before assuming a failure of the generator or regulator has occurred, check wiring against the wiring diagrams provided with the generator set and the instructions given in "Installation" section located in the Systems Operation of this manual. Also make certain all connections are tight and free of corrosion. Adjustments
Before initial operation is attempted, verify that the regulator is connected for the application. (See wiring diagram provided with the generator set and review the procedures given in "Installation" section located in the Systems Operation of this manual.)The adjustments pertaining to the voltage regulator and system operation are described in the paragraphs that follow and, except where noted, adjustment is made during initial operation and normally does not have to be repeated during the life of the voltage regulator.Generator Voltage Adjust Rheostat (VAR)
This adjustment is provided to set the generator voltage. When set to its maximum counterclockwise position, minimum generator voltage is obtained. Maximum generator voltage is obtained when the rheostat is set to its maximum clockwise position.Nominal Voltage Range Set Adjust (R2)
This adjustment is provided to extend