K65-12B Voltage Regulator Caterpillar

Illustration 1	g00899844
K65-12B Voltage Regulator (1) Knee frequency adjustment (2) Voltage adjustment

Illustration 2	g01021519

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The Cat K65-12B Voltage Regulator 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.

Operation at 50 or 60 Hz

1. Adjust the generator frequency for 60 Hz.

2. Turn the knee frequency adjustment (1) fully in the counterclockwise direction (CCW direction).

3. Turn the voltage adjustment (2) until the voltage is at 120 VAC on terminals 20, 22, and 24.

4. Turn the knee frequency adjustment (1) in the clockwise direction until the voltage begins to decrease.

5. Turn the knee frequency adjustment (1) CCW until the voltage just returns to 120 VAC. The knee frequency is set just below the nominal operating frequency.

   Note: Further CCW rotation will lower the knee frequency.

6. Connect a jumper from terminal 8 to terminal 6a in order to provide an underfrequency slope of 1 V/Hz. No connection to terminal 8 will result in an underfrequency slope of 2 V/Hz.

7. Start the generator.

8. Run the generator at no load.

9. Decrease the engine RPM. Observe the frequency that the voltage starts to decrease. If the knee frequency is lower than 5 Hz below the rated frequency, readjust the knee frequency.