Generac Power Systems 04390-1 1.6FUEL REQUIREMENTS AND RECOMMENDATIONS, 1.7FUEL CONSUMPTION

Section 1 — General Information

Guardian Air-cooled 7 kW, 12 kW and 15 kW Generators

1.6FUEL REQUIREMENTS

AND RECOMMENDATIONS

With LP gas, use only the vapor withdrawal

system. 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 your fuel.

3.Disconnect wire #0 and wire #14 from the gas solenoid located on the top of the demand regu- lator.

4.Remove the demand regulator by rotating coun- terclockwise.

5.Remove the brass hose fitting from the outlet port of the demand regulator.

6.Remove the brass metering jet (loosen counter- clockwise) from the housing port of the demand regulator located on the side of the regulator.

7.Install new LP metering jet (tighten clockwise) in the outlet port of the demand regulator.

8.Refit the brass hose fittings to the outlet port of the demand regulator.

9.Reverse procedure steps 1-4 to reinstall demand regulator.

10.Reverse the procedure to convert back to natural gas.

Figure 1.3 – Demand Regulator

Fuel pressure for both natural gas and liquid propane set ups should be 11 inches to 14 inches of water column (0.6 psi) at all load ranges.

NOTE:

A seperate gas line and regulator may be needed to assure proper gas pressure (11-14”) to the gen- erator. Low gas pressure can cause hard starting and could affect engine durability.

1.7FUEL CONSUMPTION

Model #	Nat. Gas (*)		LP Vapor (**)
	1/2 Load	Full Load	1/2 Load	Full Load
04389	74	105	0.91/33	1.21/44.1
04456	114	185	1.34/48.9	2.17/79.0
04390	148.5	240	1.73/63.2	2.80/102.3

*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.

1.8RECONFIGURING THE FUEL SYSTEM

◆1.8.1 7 KW, 410CC ENGINE

FUEL HOSE	FUEL HOSE
BRASS HOSE	BRASS HOSE
FITTING	FITTING
	FUEL JET
HOUSING	HOUSING
PORTS	PORTS

NG FUEL SYSTEM LP FUEL SYSTEM

NOTE:

The natural gas adjustment screw is preset during installation and should not need any further adjustment.

◆1.8.2 12KW AND 15KW, 990CC ENGINES

To reconfigure the fuel system from NG to LP, follow these steps:

NOTE:

The primary regulator for the propane supply is NOT INCLUDED with the generator. A fuel pres- sure of 11 to 14 inches of water column (0.6 psi) to the fuel inlet of the generator MUST BE SUP-

PLIED.

1. Turn OFF the main gas supply.

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 from the outlet port of the demand regulator (Figure 1.3).

2.Remove the engine air in baffle located on the left hand side of the battery compartment. Two M6 screws are located on top of the baffle and two M6 screws are located on the inside of the baffle towards the back.

Generac® Power Systems, Inc. 7