LINE AS-FUEL INJECTION 1114130 - Caterpillar

Illustration 1 g02198577
Typical Block Diagram of SR4B Permanent Magnet Permanently Excited (PMPE) Generator with VR6 Voltage Regulator (1) Generator lines (output voltage) (2) Generator lines (sensing voltage and AC power) (3) VR6 voltage regulator (4) Jumper (5) Main stator (6) Main rotor (7) Exciter rotor (8) Exciter stator (9) Three-phase rectifiers (10) Permanent magnet stator (11) Permanent magnet (12) Generator lines (DC excitation voltage)This manual covers the VR6 voltage regulator which is used on 4/6 and 10/12 lead self-excited generators and permanent magnet generators. The VR6 regulator is typically located in the generator terminal box. The regulator may also be located in the marshaling box. In some applications, the regulator may be remotely mounted.The VR6 voltage regulator (3) keeps the generator output voltage constant with changing loads. The voltage regulator controls the DC voltage and current that is supplied to the exciter stator (8) . The regulator senses the generator voltage through the generator sensing leads (2) . The sensing leads are connected to the following terminals: 20, 22 and 24. The sensed voltage is then compared to a reference voltage. The reference voltage value is set by the voltage adjust potentiometer on the regulator. The reference voltage value may also be set by an external voltage adjust potentiometer. When the regulator senses a decrease in output voltage due to an increase in load, the regulator will increase the DC voltage on wires F1 and F2 (12) . This increases the magnetic field in the exciter stator (8) . The increased magnetic field in the exciter stator increases the AC voltage and current, which is induced in the exciter rotor (7) . This increased three-phase AC voltage from the exciter rotor causes more AC current to flow. The three-phase AC voltage is then rectified to DC voltage by the three-phase full wave bridge rectifier (9) . The increased DC output from the bridge rectifier is carried to the main rotor (6) by conductors, which are routed through a passage in the rotor shaft. Increased current through the main rotor increases the magnetic field of the generator. The increased magnetic field induces a larger AC voltage into the main stator (5) . Therefore, the three-phase AC voltage (1) increases until the voltage regulator no longer senses a decreased output voltage.When the voltage regulator senses an increase in output voltage due to a decrease in load, the regulator will decrease the DC voltage to the stator. A decrease in generator voltage will occur due to similar responses, as described above.
Illustration 2 g00779058
The VR6 Voltage Regulator (13) Terminal strip for attachments (14) Droop adjustment (15) Factory calibration of the voltage adjustment range (16) Voltage adjustment (17) Knee frequency adjustment (18) Stability adjustment (19) Terminal strip for sensing and power
Illustration 3 g01021519
The Cat VR6 presents an electrical shock/electrocution hazard. This hazard will cause serious injury or death.Service by trained personnel only.The terminals and heat sinks are live at hazardous voltages when power is applied and for up to 8 minutes after power is removed.
There