Guardian Technologies 4389, 4456, 4390 Procedure 7KW Units, Loosen the governor clamp bolt Figure

AC GENERATORS

PART 2

SECTION 2.4

DIAGNOSTIC TESTS

generally proportional to AC frequency. A low or high governor speed will result in a correspondingly low or high AC frequency and voltage output. The governed speed must be adjusted before any attempt to adjust the voltage regulator is made.

PROCEDURE (7KW UNITS):

1.Loosen the governor clamp bolt (Figure 9).

2.Hold the governor lever at its wide open throttle position, and rotate the governor shaft clockwise as far as it will go. Then, tighten the governor lever clamp bolt to 70 inch-pounds (8 N-m).

3.Start the generator; let it stabilize and warm up at no-load.

4.Connect an AC frequency meter across the generators AC output leads.

5.Turn the speed adjust nut to obtain a frequency reading of 62 Hz.

6.When frequency is correct at no load, check the AC voltage reading. If voltage is incorrect, the voltage regulator may require adjustment.

Figure 9. Engine Governor Adjustment Single

Cylinder Engines

Figure 10. Engine Governor Adjustment

V-twin Engines

PROCEDURE (12/15 KW UNITS):

1.Loosen governor clamp bolt (See Figure 10).

2.Completely remove the idle spring.

3.With governor arm at wide open throttle position, rotate governor shaft fully clockwise. Tighten clamp bolt to 84 inch-pounds.

4.Start unit and apply full load. Use full load speed adjust screw (Figure 11) to adjust frequency to 58 Hz.

5.Remove load, stop engine, loosen the idle adjust screw and reconnect the idle spring.

6.Using your hand, push the governor arm to the closed throttle position. Make sure the idle spring does not stretch at all.

7.Restart the unit.

8.Slowly turn the idle adjust screw to adjust the no-load idle speed to 62.5 Hz.

9.The governor is now set.

Figure 11. Full Load Speed Adjust

ScrewV-twin Engines

RESULTS:

1.If, after adjusting the engine governor, frequency and voltage are good, tests may be discontinued.

2.If frequency is now good, but voltage is high or low, go to Test 13.

3.If engine was overspeeding, check linkage and throttle for binding. If no governor response is indicated refer to engine service manual.

4.If engine appears to run rough and results in low frequency, proceed tp Problem 11, Page 4.3-3.

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