Generac Power Systems 941-2 Advantages Of Gaseous Fuels, Fuel System Components, Vapor Withdrawal

Section 4.1

INTRODUCTION TO FUEL SYSTEM

GENERAL INFORMATION

Some RV generator models are equipped with fuel systems that utilize LP gas as a fuel. The initials "LP" stand for "liquefied petroleum". This gas is highly volatile and can be dangerous if handled or stored carelessly.

All applicable laws, codes and regulations pertaining to the storage and handling of LP gas must be com- plied with. The installation of such fuel systems must also be in compliance with such laws, codes and reg- ulations. Service technicians who work on these sys- tems must do nothing that might cause the system to be in non-compliance with regulations.

Regulations established by the Recreational Vehicle Industry Association (RVIA) must be followed in the installation, use and servicing of such systems.

DANGER! LP GAS IS HIGHLY EXPLOSIVE.

!THE GAS IS HEAVIER THAN AIR AND TENDS TO SETTLE IN LOW AREAS. EVEN THE LIGHTEST SPARK CAN IGNITE THE GAS AND CAUSE AN EXPLOSION. ONLY COMPETENT, QUALIFIED GAS SERVICE TECHNICIANS SHOULD BE ALLOWED TO INSTALL, TEST, ADJUST OR SERVICE THE GASEOUS FUEL SYSTEM. INSTALLATION OF A GASEOUS FUEL SYSTEM MUST BE IN STRICT COMPLIANCE WITH APPLICA- BLE CODES. FOLLOWING INSTALLATION NOTHING MUST BE DONE THAT MIGHT RENDER THE SYSTEM IN NONCOMPLI- ANCE WITH SUCH CODES.

DANGER! USE ONLY APPROVED COMPO-

!NENTS IN THE GASEOUS FUEL SYSTEM. IMPROPER INSTALLATION OR USE OF UNAUTHORIZED COMPONENTS CAN RESULT IN FIRE OR AN EXPLOSION. USE APPROVED METHODS TO TEST THE SYS- TEM FOR LEAKS. NO LEAKAGE IS PERMIT- TED. DO NOT PERMIT FUEL VAPORS TO ENTER THE VEHICLE INTERIOR.

ADVANTAGES OF GASEOUS FUELS

The use of gaseous fuels may result in a slight power loss, as compared to gasoline. However, that disad- vantage is usually compensated for by the many advantages of gaseous fuels. Some of these advan- tages are:

•A low residue content results in minimum carbon formation in the engine.

•Reduced sludge buildup in the engine oil.

•Reduced burning of valves as compared to gasoline.

•No wash-down of engine cylinder walls during cranking and startup.

•Excellent anti-knock qualities.

•A nearly homogeneous mixture in the engine cylinders.

•Fuel can be stored for long periods without break- down.

FUEL SYSTEM COMPONENTS

When the generator set is shipped from the factory, the following fuel system components are included with the unit:

1.A Fuel Lockoff Solenoid

2.The LP Gas Regulator

3.The carburetor.

4.Interconnecting lines and fittings.

Components that must be added by the generator installer include the following:

1.A VAPOR WITHDRAWAL type fuel tank.

2.A PRIMARY REGULATOR that will deliver a fuel pressure to the Fuel Lockoff Solenoid of about 11” water column.

3.Interconnecting lines and fittings.

VAPOR WITHDRAWAL

LP gas is stored in pressure tanks as a liquid. Gaseous fuel system components installed on the generator are designed for "vapor withdrawal" type systems. Such systems use the gas vapors that form above the liquid fuel in the tank. Do not attempt to use any "liquid withdrawal" type tank with the RV generator.

NOTE: "Liquid withdrawal" type systems use the liquid fuel from the tank. The liquid fuel must be vaporized before it reaches the carburetor. Fuel vaporization is usually accomplished by porting the liquid fuel through some kind of heating device.

IMPORTANT CONSIDERATIONS

When servicing the gaseous fuel system the following rules apply:

•All lines, fittings, hoses and clamps must be free of leaks. Apply pipe sealant to threads when assem- bling threaded connectors to reduce the possibility of leakage.

•Following any service, the system must be tested for leaks using APPROVED test methods.

•Optimum gas pressure at the inlet to the fuel lock- off solenoid and secondary regulator is 11 inches of water column. Do NOT exceed 14 inches water column.

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