Generac Power Systems 4270-0 - Manual (Page 28)

INSTALLATION
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Section 2 - Installation
QUIETPACT™ 75D Recreational Vehicle Generator
2.3 COOLING AND VENTILATING AIR
It is absolutely essential that an adequate flow of air
for cooling, ventilating and engine combustion be
supplied to the generator set. Without sufficient air­
flow, the engine/generator quickly overheats. Such
overheating can cause serious operating difficulties
and also may cause fire and personal injury. The
installer must make sure that sufficient air is avail­
able to the generator for cooling, ventilating and com­
bustion. The installer also must provide for a path
for exhausting the cooling air to the exterior of a com­
partment, if so equipped.
DANGER
A Never use discharged cooling air for heating or
permit such air to enter the vehicle interior. This
air contains deadly carbon monoxide gas and
other poisonous, flammable or explosive gases.
♦ 2.3.1 GENERATOR AIRFLOW____________________
This unit uses a centrifugal blower to cool the gener­
ator’s internal components. Blower fan air is then
expelled from a blower air outlet duct. The engine
cooling fan draws air in through air inlet openings,
moves that air around the engine/generator and
across the radiator, then discharges that air out the
bottom (see Figure 2.7).
Figure 2.7 - Airflow Through Engine/Generator
305mm ( 12’ ) UNRESTRICTED
UNDERFRAUe CLEARANCE
TO THE GROUND
♦ 2.3.2 COOLING AIR INLET OPENINGS_____________
The minimum size of the air inlet opening, whether
the generator is housed in a conventional compart­
ment or not, is at least 150 square inches
(975 cm*) (see Figure 2.8). This rule applies whether
inlet air is brought in through an opening in the com­
partment door, an opening in the vehicle skirt,
through ductwork, or by any other means.
NOTE:
Screening, louvers or expanded metal that cover air
openings restrict airflow. You must compensate for
this by making the actual air opening proportion­
ately larger. See Section 2.3.3 (Page 27).
Figure 2.8
-
Air Inlet in Compartment Door
150 SQUARE INCHES
UNRESTRICTED
L
MINIMUM OPENING
When the unit is installed on a suspended mounting
system, one of several different methods of supplying
airflow may be used as follows:
• Provide a door in the vehicle skirt having an air
inlet opening (Figure 2.9).
Figure 2.9 - Suspended Mount: Inlet Door
Using ductwork (Figure 2.10, Page 27). The
installer must be sure air is available to the
top of the generator since air Inlets are located at
the top.
By providing an opening in the vehicle skirt and
space behind the generator for cooling airflow
(Figure 2.11 Page 27). Recommended clearance
behind the back of the generator is at least
2 inches (50 mm).
S6 Generac* Power Systems, Inc.