K65-12B Voltage Regulator Caterpillar

Illustration 1	g00884474
Test Circuit (1) Droop adjustment (2) Factory voltage adjustment (3) Voltage adjustment (4) Knee frequency adjustment (5) Stability adjustment (6) 100 Watt light bulbs (7) 10 Ohm Resistor (8) Switch (300 VAC and 15 Amperes) (9) AGC10 fuse (10) The AC power source (120 V ± 5% )

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.

Perform the following procedure in order to determine whether the voltage regulator is providing proper excitation.

1. Connect the voltage regulator according to Illustration 1.

2. Adjust stability (5) by turning adjustment in a fully clockwise direction.

3. Turn voltage adjustment (3) for five turns in a counterclockwise direction.

4. Close switch (8) in order to apply AC power. The AC power source is 120 V ± 5%.

5. If the lights (6) turned on, turn the voltage adjustment (3) in a counterclockwise direction. The lights should decrease in intensity. The lights should finally go out. Go to step 7.

   If the lights (6) did not come on, go to step 6.

6. Turn the voltage adjustment in a clockwise direction. The lights should increase in intensity as the voltage adjustment is turned CW. The regulator will shut off and the lights (6) will turn off if one of the following conditions occurs:
   • The voltage that is being applied to the lights (6) is above 90 V for 30 seconds.

   • The voltage that is being applied to the lights (6) is above 125 V for 10 seconds.

7. Open switch (8) for at least 15 seconds. The lights (6) will flash momentarily.

8. Close switch (8) .

9. Slowly turn the voltage adjustment (3) CCW until the lights (6) come ON. Try to maintain a low light intensity to medium light intensity by adjusting the voltage adjustment (3) .

Expected Result: The light bulbs (6) operate, as described above.

Results:

• "OK": The voltage regulator functions properly.

• "Not OK": The light bulbs (6) react differently. Replace the voltage regulator.

Note: Droop (1) should be adjusted during generator's operation.

Note: Knee frequency (4) should be adjusted during generator's operation.

Note: Stability (5) should be adjusted during generator's operation.