Generac Power Systems 004916-0 - Manual (Page 9)

7
1.7 FUEL REQUIREMENTS
AND RECOMMENDATIONS
With LP gas, use only the vapor withdrawal sys-
tem. This type of system uses the vapors formed
above the liquid fuel in the storage tank.
The engine has been fitted with a fuel carburetion
system that meets the specifications of the 1997
California Air Resources Board for tamper-proof
dual fuel systems. The unit will run on natural gas or
LP gas, but it has been factory set to run on natural
gas. Should the primary fuel need to be changed to
LP gas, the fuel system needs to be reconfigured. See
Section 1.8 for instructions on reconfiguration of the
fuel system.
Recommended fuels should have a Btu content of at
least 1,000 Btus per cubic foot for natural gas; or at
least 2,520 Btus per cubic foot for LP gas. Ask the
fuel supplier for the Btu content of the fuel.
Required fuel pressure for natural gas is 5 inches
to 7 inches water column (0.18 to 0.25); and for
liquid propane vapor, 10 inches to 12 inches of
water column (0.36 to 0.43 psi).

A seperate gas line and regulator may be need-
ed to assure proper gas pressure to the genera-
tor. Low gas pressure can cause hard starting
and could affect engine durability.
1.8 FUEL CONSUMPTION
*Natural gas is in cubic feet per hour.
**LP is in gallons per hour/cubic feet per hour.
DANGER

Gaseous fuels such as natural gas and liquid
propane (LP) gas are highly explosive. Even the
slightest spark can ignite such fuels and cause
an explosion. No leakage of fuel is permitted.
Natural gas, which is lighter than air, tends to
collect in high areas. LP gas is heavier than air
and tends to settle in low areas.
1.9 RECONFIGURING THE
FUEL SYSTEM
To reconfigure the fuel system from NG to LP,
follow these steps:
1. Turn the main gas supply off.
2. Remove the carburetor fuel hose and the brass
hose fitting from the NG (right) outlet port of the
demand regulator (Figure 1.4).
3. Remove the pipe plug from the LP (left) outlet
port.
4. Install the brass hose fitting in the LP (left) outlet
port.
5. Install the pipe plug in the NG (right) outlet
port.
6. Connect the carburetor fuel hose to the LP (left)
outlet port of the demand regulator.
7. Reverse the procedure to convert back to natural
gas.
Figure 1.4 – Demand Regulator
PORT
NG OUTLET
LP OUTLET
PORT
NG OUTLET
PORT
PORT
LP OUTLET
NG FUEL SYSTEM LP FUEL SYSTEM
1.10 LOCATION
1.10.1 GENERATOR
Install the generator set, in its protective enclosure,
outdoors, where adequate cooling and ventilating air
is always available. Consider these factors:
• Install the unit where air inlet and outlet open-
ings will not become obstructed by leaves, grass,
snow, etc. If prevailing winds will cause blowing or
drifting, consider using a windbreak to protect the
unit.
• Install the generator on high ground where water
levels will not rise and endanger it.
• Allow sufficient room on all sides of the generator
for maintenance and servicing. A good rule is to
allow three feet of space on all sides.
• Where strong prevailing winds blow from one
direction, face the generator air inlet openings to
the prevailing winds.
• Install the generator as close as possible to the fuel
supply, to reduce the length of piping.
• Install the generator as close as possible to
the transfer switch. HOWEVER, REMEMBER
THAT LAWS OR CODES MAY REGULATE THE
DISTANCE.
The genset must be installed on a level surface. The
base frame must be level within two (2) inches all
around.
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Section 1 — General Information
Air-cooled 11 kW Generators
Model # Nat. Gas (*) LP Vapor (**)
1/2 Load Full Load 1/2 Load Full Load
04916 115 202 1.38/55.6 2.15/86.4