GAUGE-PRESSURE 3995670 - Caterpillar

Voltage Adjustment - Single Unit Operation
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.
Remove the generator's access panel.
Remove the sealing screws in order to gain access to the Level and Gain Adjustment Controls.
Turn the Gain Control counter-clockwise to zero. After turning the Gain Control counterclockwise to zero, turn the Gain Control five turns clockwise.
Perform the required maintenance on the engine prior to starting the engine.
Start the engine and allow the engine to warm up.
Increase the engine speed to the engine's full-governed speed (high idle).
Connect a voltmeter. Observe the voltmeter reading. If the desired voltage is not indicated, set the no-load voltage with level control.
Close the circuit breaker and gradually apply full load. Adjust the governor control until nameplate frequency is indicated on the frequency meter or until an engine tachometer indicates rated speed.Note: Full load must be applied to properly adjust regulator.
With full load applied, perform one of the following two steps.
If voltmeter reading increases with full load applied, turn the gain control in a counter-clockwise direction.
If voltmeter reading decreases with full load applied, turn the gain control in a clockwise direction.
Remove load. If necessary, adjust the voltage level control in order to obtain the desired voltage.
Apply load. Observe voltmeter reading. Repeat Steps 8 through 11 until no-load voltage equals full-load voltage.
Replace the sealing screws in the Level and Gain access holes (VR-3 only).
Install the generator access panel.Voltage Adjustment - Parallel Operation
The Voltage Level Adjustment and the Voltage Droop Adjustment determine the amount of circulating currents between paralleled generators. Carefully matched voltage regulator adjustments will reduce the circulating currents. Loads of .8 power factor (primary motors) require a generator voltage droop of approximately 5%. Voltage droop is expressed as the percentage of voltage change from no load to full load. Use the same voltmeter to make adjustments on each unit to be paralleled.
Loosen the locknut on the Voltage Droop Control. Turn the Voltage Droop Control fully counter-clockwise.
Adjust the voltage as described above (Single Unit Operation).
With the engine running at high-idle speed, turn the Voltage Droop clockwise to approximately one half of full range.Note: If driven load is to be unity power factor, set the Voltage Droop Control on all generators at one half of full range and then proceed to Step 8. If driven load includes reactive load