Generac Power Systems 04389-3, 04456-3, 04390-3 System Set Led, Reconfiguring The Fuel System

Section 1 — General Information

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

1.6SYSTEM SET LED

The “System Set” LED is lit when all of the following conditions are true:

1.The AUTO/OFF/MANUAL switch is set to the AUTO position.

2.The utility voltage being supplied to the unit is being sensed by the PCB. If the utility sense volt- age is not connected to the unit or if it is below 168 volts AC, then the system set light will flash rapidly. This indicates that if the AUTO/OFF/ MANUAL switch is placed in the Auto position, the generator will start.

3.The “Not In Auto” dip switch is set to the OFF position on the control board.

4.No alarms are present, for example, low oil pres- sure, high temperature, etc.

1.7FUEL 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 1.9 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 colum (0.18 to 0.25 psi); and for liquid propane, 10 inches to 12 inches of water column (0.36 to 0.43 psi).

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.

1.9RECONFIGURING THE FUEL SYSTEM

‹1.9.1 7 KW, 410CC ENGINE

To reconfigure the fuel system from NG to LP, follow these steps (Figure 1.3):

NOTE:

The primary regulator for the propane supply is NOT INCLUDED with the generator. A fuel pres- sure of 10 to 12 inches of water column (0.36 to

0.43psi) to the fuel inlet of the generator MUST BE SUPPLIED.

1.Turn off the main gas supply (if connected).

2.Open the roof and remove the door.

3.Remove the battery (if installed).

4.Disconnect wire #0 and wire #14 from the gas solenoid on top of the demand regulator.

5.Remove the carburetor fuel hose from the outlet port of the demand regulator.

6.Remove the demand regulator by removing the fastener that retains the regulator mounting bracket.

7.Remove the square headed steel pipe plug from outlet port #1 and the brass hose barb fitting from outlet port #2.

Figure 1.3 – Demand Regulator

NOTE:

Any piping used to connect the generator to the fuel supply should be of adequate size to ensure the fuel pressure NEVER drops below 4 inches water colum for natural gas or 10 inches water column for liquid propane for all load ranges.

1.8FUEL CONSUMPTION

Model #	Nat. Gas (*)		LP Vapor (**)
	1/2 Load	Full Load	1/2 Load	Full Load
04389	66	119	0.82/30	1.47/54
04456	152	215	1.53/56	2.08/76
04390	156	220	1.58/58	2.40/88

FUEL HOSE

BRASS HOSE FITTING

ADJUSTMENT SCREW

HOSE & PLUG

SWITCHED SIDES

PIPE	FUEL HOSE
PLUG

BRASS HOSE

FITTING

OUTLET

PORT

FUEL JET

*Natural gas is in cubic feet per hour.

**LP is in gallons per hour/cubic feet per hour.

*** Values given are approximate.

NG FUEL SYSTEM LP FUEL SYSTEM

7