CARTRIDGE AS 4441816 - Caterpillar

In order to obtain an optimal setting for stability, monitor the line voltage on the generator output terminals and the excitation voltage on the R438 AVR. Use terminals "E+" and "E-" on the R438 AVR in order to monitor the excitation voltage. A rapid change in the voltage (oscillation) between terminals "E+" and "E-" will indicate unstable regulation. Rotate the stability adjustment "P3" counterclockwise. Rotate "P3" 1/3 clockwise. Start the engine. Adjust the speed of the engine in order to achieve an output frequency of 48 Hz for a generator that is rated for 50 Hz or 58 Hz for a generator that is rated for 60 Hz. Run the generator with no load. Rotate Adjustment "P2" in order to adjust the voltage level of the generator to the rated voltage. Note: If the generator is running in parallel with another generator, refer to the section droop-adjust for the no-load voltage level.After the generator has reached the rated voltage, observe the regulation of the line voltage and rotate the stability adjustment "P3" in the counterclockwise direction until the voltage starts to oscillate. Rotate the stability adjustment "P3" in the clockwise direction in order to slow the response time slightly.Note: If it is difficult to obtain a stable voltage, try adjusting stability with and without the "ST2" jumper. Cutting the "ST2" jumper will change the characteristics of the stability circuit from normal to fast.Install LAM jumper "ST5" across the terminal pins to activate the LAM feature. Vary the engine speed in order to achieve an output frequency under and over 48 Hz for a generator that is rated for 50 Hz, or around 58 Hz for a generator that is rated for 60 Hz. The generator frequency should change approximately 10 to15% when crossing this frequency point. Set the engine operating speed to the desired nominal frequency. Set the jumper "ST5" and "ST10" to the desired operation for the operating frequency. The jumpers will be set to either constant V/Hz or LAM operation. Verify that the voltage output from the generator is stable throughout the load range of the generator.
Voltage Droop - Clockwise to increase droop.
Voltage - Set to fully counterclockwise for minimum.
Stability - Set counterclockwise to increase stabilty.
Excitation Current Limit - Fully counterclockwise for 4 Amperes.