User Guide

6. When frequency is correct at no load, check the AC
voltage reading. If voltage is incorrect, the voltage
regulator may require adjustment.
1.8.2 12 KW AND 15 KW UNITS
1. Loosen governor clamp bolt (See Figure 1.6).
2. Completely remove the idle spring.
3. With governor arm at wide open throttle position
(rotated fully clockwise), 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 1.7) to adjust frequency to 58
Hz.
5. Remove load, stop engine, loosen the idle adjust
screw and reconnect the idle spring.
6. Push the governor arm to the closed throttle position.
Make sure the idle spring does not stretch at all.
Figure 1.6 — Engine Governor Adjustment
V-twin Engines
Figure 1.7 — Full Load Speed Adjust Screw
V-Twin Engines
7. Restart the unit.
8. Slowly turn the idle adjust screw to adjust the no-load
idle frequency to 63-63.5 Hz (with top open).
9. The governor is now set.
1.9 VOLTAGE REGULATOR
ADJUSTMENT
With the frequency between 62-63 Hertz, slowly turn the
slotted potentiometer (Figure 1.8) until line voltage reads
247-252 volts.
Figure 1.8 – Voltage Adjustment Potentiometer
NOTE:
The access panel on top of the control panel must be
removed to adjust the voltage regulator.
NOTE:
The voltage regulator is housed above the
generator's control panel. The regulator maintains a
voltage in direct proportion to frequency at a 2-to-1
ratio. For example, at 62 Hertz, line-to-neutral voltage
will be 124 volts.
1.10 ADJUSTING GH-410/GT-990
VALVE CLEARANCE
After the first 6 months of operation, adjust the valve
clearance in the engine.
Important: If feeling uncomfortable about doing this
procedure or the proper tools are not available, please
contact a Carrier dealer for service assistance. This step
necessary to insure the longest life for the engine.
To adjust valve clearance:
• Make sure the engine is at room temperature.
• Make sure that the spark plug wire is removed from the
spark plug and out of the way.
◆
Governor Clamp Bolt
Governor
Shaft
(Rotate
Clockwise)
Idle Spring
No Load Idle
Adjustment Screw
Full Load
S
peed Adjust
S
crew
Section 1 — Post Installation Start-up and Adjustments
Carrier Air-cooled 7 kW, 12 kW and 15 kW Generators
8 Carrier