Generac Power Systems 941-2 - Manual (Page 87)

Section 5.2
ENGINE COOLING SYSTEM
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 interior. This air contains deadly car-
bon monoxide gas and other poisonous,
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 1). 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 1 — Air Flow Through Engine-Generator
COOLING AIR INLET OPENINGS
Ideally, you should provide three air inlet openings,
whether the generator is housed in a conventional
compartment or not. Two of the openings should be
10 square inches and located as shown in Figure 2.
The third opening should provide for a minimum of 40
square inches unrestricted and be located lower on
the compartment door.
NOTE: Screening, louvers, or expanded metal that
cover air openings restrict air flow that you must
compensate for by making the actual air opening
proportionately larger. See “Compensating for
Restrictions.”
For conventional compartment mounted units, the air
inlet is generally provided in the compartment door.
Figure 2 — Air Inlet in Compartment Door
IMPORTANT: IF YOU PLAN TO INSTALL THE
GENERATOR IN A COMPARTMENT, BE SURE
TO LEAVE AT LEAST ONE INCH (2” recom-
mended) OF CLEARANCE BETWEEN THE GEN-
ERATOR AND COMPARTMENT WALLS AND
CEILING. INCLUDE 26 GAUGE GALVANIZED
STEEL LINING AND SOUND INSULATION WHEN
YOU MEASURE FOR THIS 1 INCH (2” recom-
mended) CLEARANCE.
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 3, next page).
• Using ductwork (Figure 4 on next page). 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
above the generator for cooling air flow (Figure 5 on next
page). Recommended clearance above the top of the
generator is at least 2 inches.
Page 5.2-1
10 SQUARE INCHES
(OPTIONAL OPENINGS)
40 SQUARE
INCHES
(MINIMUM
OPENING)