ROTOR 4J7508 - Caterpillar

Remote Voltage Control
Partial View Of Regulator
(1) Potentiometer. (2) Jumper. (3) Regulator.Generator output voltage level can be controlled from a remote location. This is done by connecting potentiometer (1) between terminals 6 and 7 on voltage regulator (3). Remove jumper (2) between terminals 4 and 7 for remote voltage level control.For acceptable voltage control, the remote mounted potentiometer must be 10k ohms 5% with three turns and a dielectric strength of 1000 VAC minimum.The terminals of the remote mounted potentiometer are fragile. The wiring connected to remote mounted potentiometer (1) should not have a diameter larger than 18 gauge. Larger diameter wire is not recommended. The wire should be 600 volt class with a 90°C (194°F) insulation. Either jumper (2) or remote potentiometer (1) is required for regulator operation.Manual Voltage Control
Manual Voltage Control Schematic With Power Transformer Manual Voltage Control Schematic With Power Transformer and Sensing
Manual Voltage Control Panel
(1) Switch (OFF, AUTO and MAN positions). (2) Voltage control rheostat. (3) Fuse.The manual voltage control can be used to control generator voltage when there is a failure in the generator regulator assembly. It will manually control the current flow to exciter stator L1.The manual voltage control panel has switch (1) and voltage control rheostat (2) for the manual operating mode.Switch (1) is used to make the selection between AUTO, MAN and OFF. In the "AUTO" position, the VR3 regulator controls the generator voltage. In the "OFF" position, the voltage will go to zero. In the "MAN" position, generator voltage is controlled by voltage control rheostat (2). The Manual Voltage Control Panel must not be installed in a location that is subject to engine vibrations or directly to outside weather. When the manual voltage control is operating in the "Manual" mode, it is not necessary for the VR3 regulator to be connected to the generator. However, the manual control must remain connected to generator sensing lines No. 20 and No. 24.Voltage Droop Transformer And Adjustment Rheostat For Parallel Operation
Generator And Regulator Schematic
(1) Voltage droop transformer. (2) Voltage droop rheostat. (3) Lead. (4) Main stator.Operation of generators in parallel requires voltage droop as reactive load is increased. Droop transformer (1) and adjustment rheostat (2) are required to provide the voltage droop function. The transformer senses load current in lead (3) of main stator (4). Droop rheostat (2) provides adjustment of droop voltage. Rheostat (2) is located directly next to the regulator on the regulator mounting bracket.Transformer (1) is standard on some generators and is an attachment on others. Rheostat (2) is an attachment on all units. Droop transformer (1) is a special ratio transformer. Droop transformer (1) must be installed on generator phase lead T2 with transformer polarity connections as shown.