Generac Power Systems 941-2 Service Manual page 73

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.
INTRODUCTION TO FUEL SYSTEM
• 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.
Section 4.1
Page 4.1-1