Guardian 4389 Repair Manual page 45

AC GENERATORS
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 volt-
age reading. If voltage is incorrect, the voltage regulator
may require adjustment
PROCEDURE
(7KW UNITS WITH DUAL GOVERNOR SPRINGS):
1. Loosen the governor clamp bolt (Figure 8).
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 a frequency meter across the generators AC
output leads.
5. Turn the primary adjust screw to obtain a frequency
reading of 61.5 Hz. Turn the secondary adjust screw to
obtain a frequency reading of 62.5 Hz.
6. When frequency is correct at no load, check the AC volt-
age reading. If voltage is incorrect, the voltage regulator
may require adjustment.
Figure 9. Engine Governor Adjustment
V-twin Engines
PROCEDURE (12/15 KW UNITS):
1. Loosen governor clamp bolt (See Figure 9).
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.
PART 2
4. Start unit and apply full load. Use full load speed adjust
screw (Figure 10) 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 10. Full Load Speed Adjust
Screw V-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 fre-
quency, proceed to Problem 11, Section 4.3.
TEST 13 - CHECK AND ADJUST VOLTAGE
REGULATOR
DISCUSSION:
For additional information, refer to description and
components Section 2.1.
SECTION 2.4
DIAGNOSTIC TESTS
Page 43