ADJUSTING THE REGULATOR
(NATURAL GAS ONLY)
Although the generator has been factory set to pro-
vide maximum power, it may be necessary in some
areas to adjust this setting. Because natural gas has
different BTU or power content across the country
the engine may not perform as designed.
If experiencing engine problems at high or full load
conditions follow these steps. It will require a fre-
quency meter to perform this procedure.
1. Turn off utility power to the main distribution
panel in the house. This can be done by switching
the service main breaker to the off or open posi-
2. Allow the generator to start before loading the
generator. Confirm the no-load frequency with
the roof open and door off is set at 63-63.5 Hz.
Transfer load to emergency circuits.
3. Turn on appliances, lights, pumps, etc., that are
on the emergency circuits in an attempt to fully
load the generator. Be cautious not to overload
the generator. Use the following chart as a guide:
4. When full load has been achieved. Connect a fre-
quency meter to the output lugs of the generator's
main line circuit breaker.
5. The fuel regulator is fitted with one (7 kW), or two
(12 & 15 kW) adjustment screws. While watching
the frequency meter, slowly turn the adjustment
screw clockwise or counterclockwise one at a
time until highest frequency is read on the meter.
Only limited adjustment is available between the
set pins. Under no circumstances should any of
the pins be removed (Figures 2.1 and 2.2).
Figure 2.1 — Dual Fuel Regulators
Power Systems, Inc.
Section 2 — Post Installation Start-up and Adjustments
Generac Air-cooled 7 kW, 12 kW and 15 kW Generators
6. When the highest frequency is reached maximum
power has been set. Then turn both adjustment
screws 1/4 turn counterclockwise. Regulator is
Figure 2.2 — Placement of Regulator
7. Turn utility power to the main distribution panel
back on. This can be done by switching the serv-
ice main breaker to the on or closed position.
Allow the generator to shut down.
Do not make any unnecessary adjustments.
Factory settings are correct for most applica-
tions. However, when making adjustments, be
careful to avoid overspeeding the engine.
If this procedure or equipment are not available,
locate the nearest Generac Guardian Dealer and they
can perform the adjustments.
A service fee may be charged for this adjustment.
ENGINE GOVERNOR ADJUSTMENT
If both AC frequency and voltage are correspondingly
high or low, adjust the engine governor as follows:
7 KW UNITS
1. Loosen the governor clamp bolt (Figure 2.3).
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
4. Connect an AC frequency meter across the gener-
ators AC output leads.
5. Turn the speed adjust nut to obtain a frequency
reading of 63 Hz.