Generac Power Systems NP-40G - Manual (Page 53)

Section 3.1- INTRODUCTION TO FUEL SYSTEM
General
Recreational vehicle generators equipped with a gas­
oline fuel system are usually Installed so that they share
the fuel supply tank with the vehicle engine. When this
Is done, the generator Installer must never tee off the
vehicle fuel supply line to deliver fuel to the generator.
When the generator fuel supply line Is teed off the
vehicle’s fuel supply line, the more powerful vehicle
engine’s fuel pump will starve the generator when both
are running. In addition, when the vehicle engine Is not
running the generator fuel pump will draw all of the
gasoline from the vehicle engine line or even from the
vehicle engine carburetor. This will result in hard starting
of the vehicle engine.
One method of sharing the same fuel supply tank is to
install a special fitting at the tank outlet so that two fuel
dip tubes can be fitted In the tank (Rgure 1). Another
method Is to Install a new outlet In the tank. If the tank
has an unused outlet, it can be used.
A second fuel dip tube can be Installed In the original
tank outlet if the tank outlet Is large enough to accommo­
date two dip tubes. The required fittings can be made at
a machine shop. To install a second fuel outlet on the
tank means removing the tank to braze or weld a new
fitting Into place.
DANGER!
ATTEMPTING TO WELD OR BRAZE ON A FUEL
TANK, EMPTY OR NOT, IS EXTREMELY DAN­
GEROUS. FUEL VAPORS IN THE TANK WILL RE­
SULT IN AN EXPLOSION.
The generator’s fuel dip tube in the tank should be
shorter than the vehicle engine’s dip tube. This will
prevent the generator from consuming the entire fuel
supply.
DANGERI
THE FUEL SYSTEM DESIGNED AND INSTALLED
BY THE GENERATOR MANUFACTURER IS IN
STRICT COMPLIANCE WITH STANDARDS ES­
TABLISHED BY THE RECREATIONAL VEHICLE
INDUSTRY ASSOCIATION (RVIA). NOTHING
MUST BE DONE DURING MAINTENANCE THAT
WILL RENDER THE SYSTEM IN NON-COMPLI­
ANCE WITH THOSE STANDARDS.
DANGER!
THERE MUST BE NO LEAKAGE OF GASOLINE
OR GASOLINE VAPORS INTO THE VEHICLE. THE
GENERATOR COMPARTMENT MUST BE VAPOR-
TIGHT TO PREVENT ENTRY OF FUEL VAPORS
OR FUMES INTO THE VEHICLE. THE
GENERATOR’S VENTILATION SYSTEM MUST
PROVIDE A FLOW OF AIR THAT WILL EXPEL
ANY FUEL VAPOR ACCUMULATIONS.
Recommended Fuel
Use a high quality UNLEADED gasoline. Leaded REG­
ULAR grade gasoline Is an acceptable substitute.
Do NOT use any fuel containing alcohol, such as
“gasohol“. If gasoline containing alcohol is used, it must
not contain more than 10% ethanol and It must be re­
moved from the generator fuel system during storage,
do NOT use fuel containing methanol. If any fuel con­
taining alcohol Is used, the system must be inspected
more frequently for leakage and other abnormalities.
Evaporation Control Systems
Federal and state laws have Imposed strict evapora­
tive controls on gasoline fuel systems. The recreational
vehicle Industry has complied with such strict regula­
tions by using specially designed fuel tanks, tank filler
tubes and gas caps. Special canisters are often used to
collect the gasoline vapors rather than let them escape
into the atmosphere.
Such systems are designed to operate within very
critical pressure ranges. For that reason, the vehicle
manufacturer’s fuel supply system design must not be
altered. Service technicians working on the RV genera­
tor systems must not do anything that might change the
vehicle fuel system design.
Figure 2. Typical Gasoline Fuel System
CARBURETOR
CUSTOMER
CONNECTION
FUEL
FILTER
Page 3.1-1