VALVE-EXHAUST 1642542 - 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 terminals The 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.Caterpillar Digital Voltage Regulator (CDVR)
Illustration 3 g01115009The Caterpillar Digital Voltage Regulator (CDVR) is a microprocessor based voltage regulator. Control power for the CDVR is supplied from an external 24 DCV source. The power stage of the CDVR can be supplied from a multi-pole, high frequency, permanent magnet generator (PMG), from the generator output (shunt excitation), or from auxiliary windings (AREP) that are included on some generators. Connections to the CDVR are made through three plug type connectors. The communication between the CDVR and a service tool is accomplished using a CANBUS protocol.The CDVR has the following features:
Three control modes:
Automatic voltage regulation (AVR)
Power factor (PF) regulation
Reactive power (VAR) regulation
Programmable stability settings
Soft start control with an adjustable time setting in AVR mode
Dual slope voltage versus frequency (V/Hz) characteristic
Three-phase or single-phase voltage sensing
Single-phase current sensing
Field current and field voltage sensing
Ten protection functionsAdjustment 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