Generac 00784-2 - Manual (Page 28)

26 Generac ® Power Systems, Inc.
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.
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
Engine operation drives cooling fans for the two-stage
cooling air system. A pressure fan draws cooling air
into the top of the generator (Figure 2.9). This airflow
cools the engine/generator and electronic compo-
nents. The second part of the cooling system, a suc-
tion fan, draws air that is heated from a hot engine
into a collector pan at the base of the unit. This heat-
ed air (although cooler than exhaust muffler) is then
deflected out the bottom toward the ground.
Figure 2.9 – Airflow Through Engine/Generator
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 100 square inches (see
Figure 2.10). This rule applies whether inlet air is
brought in through an opening in the compartment
door, an opening in the vehicle skirt, through duct-
work, 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 propor-
tionately larger. See Section 2.3.3 (Page 27).
Figure 2.10 – Air Inlet in Compartment Door
NOTE:
Be sure to meet the minimum clearances illustrat-
ed in Figure 2.4 (Page 23).
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 2.11).
Figure 2.11 – Suspended Mount: Inlet Door
• Using ductwork (Figure 2.12, 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 2.13 Page 27). Recommended clearance
behind the back of the generator is at least 1/2 inch
(13 mm).
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Section 2 – Installation
PRIMEPACT 50 and 70 (50Hz) Recreational Vehicle Generators