Installation Guide
18
20 kW
(18 kW)
17 kW
15.3 kW
Cu Ft/Hr 260 248Full Load
BTU/Hr 260000 248000
Cu Ft/Hr 240 2183/4 Load
BTU/Hr 240000 218000
Cu Ft/Hr 187 1701/2 Load
BTU/Hr 187000 170000
Cu Ft/Hr 135 1281/4 Load
BTU/Hr 135000 128000
Cu Ft/Hr 99 99Exercise
BTU/Hr 99000 99000
Recommended
Energy Content of
FuelHeating Value:
LP Vapor Natural Gas
Heating Value:
BTU per gallon (gross**)
Cubic feet (gas)
91,547
2,500
1,000
Fuel Type
An important consideration affecting the entire installation
is the type of fuel used by your generator. The system was
factory tested and adjusted using natural gas, but can be
converted to use LP vapor. For correct engine function,
factors that are inherent to each of these fuels, like your
location and the duration of possible utility interruptions, are
important considerations in the following fuel guidelines:
• Use clean, dry fuel that is free of moisture or
any particulate material. Using fuels outside the
recommendation values that follow can cause
performance problems.
• In engines set up to run on propane (LP), commercial
grade HD5 propane with a minimum fuel energy of 2500
BTUs/ft3 with maximum propylene content of 5% and
butane and heavier gas content of 2.5% and minimum
propane content of 90% is required.
Natural gas rating will depend on specific fuel, but typical
derates are between 10 and20% of the LP gas rating.
Natural gas or LP engines are certified to operate on natural
or liquid propane gas. The emissions control system for this
engine is EM (Engine Modifications).
Fuel Pressure
Both LP vapor and natural gas fuel supply pressure at the
generator’s fuel inlet port and must be between the following
levels at full load with all gas appliances turned on and in
operation.
• NG is 3.5-7” W.C.
• LP is 11-14” W.C.
Make sure that all gas line shutoff valves are OPEN and
that adequate fuel pressure is available whenever automatic
operation is desired.
For Natural Gas fuel pressure levels of 3.5 - 5" W.C., replace
the regulator assembly with service kit 6331-00 (available at
your local service dealer).
Power Loss
Air density is less at high altitudes, resulting in less available
engine power. Engine power will decrease by 3.5% for each
1,000 feet (300 m) above sea level and by 1% for each
10° F (5.6°C) above 77°F (25°C). Generators located in
these conditions must have their transfer switch adjusted
appropriately for this power decrease. See your Automatic
Transfer Switch manual on how to adjust for the power
decrease.
The Gaseous Fuel System
Fuel Pipe Sizing
NFPA 54 and 58 are common resources. The installer must
consider the specific gravity of gas, compensate for a nominal
amount of restriction from bends and fittings, and refer to
federal and local codes for guidance.
Fuel Conversion
The engine of your home generator system is factory
Calibrated and set to operate on natural gas (NG). It may also
be operated on liquefied petroleum (LP) vapor.
NOTICE Units are set to NG at the factory.
To convert to either fuel, follow these steps:
1. Put the key into the lock of the front panel. Lightly push
down on the roof above the lock, and then turn the key
one quarter turn clockwise.
2. Lift the roof to the open position.
3. Push the control panel OFF button.
4. Remove the battery panel.
5. Remove the 15 Amp fuse.
6. Remove utility power to generator to de-energize the
battery charger.
7. Disconnect the negative (-) cable at the battery.
8. Remove the rear panel.
9. Find the fuel selector switch (A) on top of the fuel
regulator (B).
Not for
Reproduction