Generac Power Systems 91355 - Manual (Page 12)

COOLING AND VENTILATING AIR
It is absolutely essential that an adequate flow of air
for cooling, ventilating and engine combustion be sup­
plied to the generator set. Without sufficient air flow,
the engine-generator quickly overheats. Such over­
heating can cause serious operating difficulties and
may also cause fire and personal injury. The installer
must make sure that sufficient air is available to the
generator for cooling, ventilating and combustion. The
installer must also provide for a path for exhausting
the cooling air to the exterior of a compartment, if so
equipped.
DANGER: NEVER USE DISCHARGED
COOLING AIR FOR HEATING OR PERMIT
SUCH AIR TO ENTER THE VEHICLE INTE­
RIOR. THIS AIR CONTAINS DEADLY CAR­
BON MONOXIDE GAS AND OTHER POISO­
NOUS,
FLAMMABLE OR EXPLOSIVE
GASES.
GENERATOR AIR FLOW
Engine operation drives cooling fans for the 2-stage
cooling air system. A pressure fan draws cooling air
into the top of generator and into the side of the con­
trol panel (Figure 13). This air flow cools the engine-
generator and electronic .components. The second
part of cooling system, a suction fan, draws air that is
heated from a hot engine into a collector pan at the
base of the unit. This heated air (although cooler than
exhaust muffler) is directed across the muffler to cool
it. The heated air flow is then deflected out the bottom
toward the ground.
Figure 13 — Air Flow Through Engine-Generator
COOLING AIR INLET OPENING
Minumum size of the air inlet opening, whether the
generator is housed in a conventional compartment or
not, is at least 100 square inches. This rule applies
whether inlet air is brought in through an opening in
the compartment door (Figure 14) or other means.
NOTE: Screening, louvers, or expanded metal that
cover air openings restrict air flow that you must com­
pensate for by making the actual air opening propor­
tionately larger. See “Compensating for Restnctions."
For conventional compartment mounted units, the air
inlet is generally provided in the compartment door.
IMPORTANT: IF YOU PLAN TO INSTALL THE GEN­
ERATOR IN A COMPARTMENT, BE SURE TO
LEAVE AT LEAST ONE AND A HALF (1-1/2") INCH­
ES OF CLEARANCE BETWEEN THE GENERATOR
AND COMPARTMENT CEILING. INCLUDE 26
GAUGE GALVANIZED STEEL LINING AND SOUND
INSULATION WHEN YOU MEASURE FOR THIS 1-
1/2 INCH CLEARANCE. ALLOW 1” ON ALL SIDE
WALLS.
Figure 14 — Air Inlet in Compartment Door
MINIMUM FREE INLET
AREA =100 INCHES^
When the unit is installed on a suspended mounting
system, one of several different methods of supplying
air flow may be used as follows:
• Provide a door in the vehicle skirt having an air
inlet opening (Figure 15).
Figure 15 — Suspended Mount: Inlet Door
MINIMUM FREE I
INLET AREA
100 INCHES’ Em?
f
• IL.
Using ductwork (Figure 16 on Page 11). The
instailer 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 above the generator for cooling air flow
(Figure 17 on Page 11). Recommended clear­
ance above the top of the generator is at least 1 -
1/2 inches.
—
10
—
L