BALL BEARING 2H3712 - Caterpillar

Except for the oilfield generators, all Caterpillar SR4B generators are provided with voltage regulators. The voltage regulator controls the generator output voltage. VR3F
Illustration 1 g00626331
Adjustment Controls of the VR3F Regulator (1) Voltage droop potentiometer (2) Voltage level potentiometer (4) Fuse(s)The VR3F regulator has voltage droop capability (1). The VR3F regulator has the voltage level control (2). However, the VR3F regulator does not have voltage gain capability.Voltage droop and voltage level are controlled by multiturn potentiometers. The adjustment screws on the potentiometers do not have a fixed stop. When the potentiometer reaches the end of adjustment, a ratchet action begins. The beginning of a ratchet action can be felt with the adjusting tool. The adjustment screw can be turned past the potentiometer stop (ratchet action) without further changing the potentiometer setting.Digital Voltage Regulator
Illustration 2 g00883469
Digital Voltage Regulator (DVR) (1) Display (2) Function key (3) Scroll down key (4) Scroll up key (5) Keypad (6) J1 connector (7) Screw terminalsThe digital voltage regulator (DVR) is a microprocessor-based voltage regulator. The parameters are preset at the factory or the parameters can be modified in order to meet the specific requirements on the site. Certain system parameters can also be monitored on the display (1) of the DVR. Keypad (5) is used to change the information that is shown on the display. J1 connector (6) is used to join the DVR to a personal computer. Screw terminals (7) are used to join the DVR to the generator and various customer options.Adjustment Procedure for the Voltage Regulators
VR3F
Note: The VR3F regulator is protected by a fuse(s). The VR3F regulator also has a solid-state overcurrent protection. If a fuse becomes open, contact a Caterpillar dealer.
Remove the access panel of the generator.
Loosen the locknut on the voltage droop potentiometer (1). Remove the protective screw from the voltage level potentiometer (2) .
Turn voltage droop potentiometer (1) counterclockwise to zero droop. Tighten the locknut. Voltage droop potentiometer (1) is located next to the regulator.
Perform required maintenance on the engine before you start the engine.
Start the engine. Allow the engine to warm up. Refer to the Safety Section, "Engine Starting".
Increase engine speed to full governed rated speed (high idle).
Observe the voltmeter reading. If the desired voltage is not indicated, set the no-load voltage with the voltage level potentiometer (2) or the voltage adjust rheostat. The voltage adjust rheostat is located on the control panel.
Close the load circuit breaker. Apply full load gradually. Adjust the governor control until the nameplate frequency is on the frequency meter or until the rated speed is displayed on the tachometer. The unit of measurement for frequency is Hertz. The unit of measurement for the rated speed is RPM.
Remove the load. If necessary, adjust the voltage level potentiometer (2) in order to obtain the desired voltage.
Apply the load. Observe the voltmeter reading. Repeat Steps 8 and 9 until the voltage at no load equals the voltage at full load.
Tighten the locknuts. Install the protective screws on the respective potentiometers. Install the access panel of the generator. STOP.Digital