Generac Power Systems NP Series User manual

Manual No. 91355
INSTALLATION
Manual
NP Series and Q Series
AIR-COOLED
RECREATIONAL VEHICLE
GENERATORS
For Models Powered by Gasoline and LP GAS
CORPORATION
Revision 6 (10/6/97)
Printed in U.S.A.

GENERAL SAFETY RULES
THE MANUFACTURER SUGGESTS THAT THESE “RULES” FOR SAFE OPERATION BE
COPIED AND POSTED IN POTENTIAL HAZARD AREAS OF THE RECREATIONAL VEHICLE.
SAFETY SHOULD BE STRESSED TO ALL OPERATORS AND POTENTIAL OPERATORS OF
THIS EQUIPMENT.
WARNING:
The engine exhaust from this product
contains chemicals known to the State
of California to cause cancer, birth
defects, or ot her reproductive harm. _
NOTICE TO INSTALLER
The Installation Instructions have been published by
Generac Corporation to aid in the installation of the
products described in this manual. Generac assumes
that installation personnel are familiar with the proce¬
dures for installing such products, or similar products
that Generac manufactures. Generac also assumes
that personnel have been trained in the recommended
installation procedures for these products and that
such training includes (a) use of common hand tools,
(b) use of special Generac tools, and (c) use of any
tools and/or equipment from other suppliers.
We could not possibly know of and advise the recre¬
ational vehicle trade of all conceivable methods, proce¬
dures or techniques by which to perform an installation.
We could not know of the possible hazards that might
result from each installation method, procedure or
technique. We have not undertaken any such wide
evaluation. Therefore, people who use a method, pro¬
cedure or technique that Generac does not specifically
recommend must first completely satisfy themselves
that their safety, the safety of the vehicle's occupants
and the products's safety is not endangered by the
method, procedure or technique selected.
information, illustrations, specifications, etc., contained
in this Installation Manual are based on the latest infor¬
mation available at the time of publication. Every effort
has been expended to be sure that such data is both
accurate and current. However, the manufacturer
reserves the right to change, alter or otherwise improve
his product at any time without prior notice.
SAFETY RULES
Gasoline is extremely FLAMMABLE and its vapors are
EXPLOSIVE. Do not permit smoking, open flame,
sparks or any source of heat in the vicinity while han¬
dling gasoline. Comply with all regulations governing
the storage and handling of gasoline.
• Fuel lines must be properly installed, properly fas¬
tened and free of leaks. There must be no possibility
of gasoline vapors entering vehicle interior.
• You are required to install an approved, flexible,
non-conductive fuel line between the generator fuel
connection point and rigid fuel lines.
A If the generator can be equipped with a liquid
propane (LP) gas fuel system, install the unit so it
complies with all codes, standards and regulations
pertaining to such systems. LP gas is highly explosive.
The gas tends to settle in low areas where even the
slightest spark can ignite it and cause an explosion.
Do not allow gas vapors to enter the vehicle.
• Engine exhaust gases contain DEADLY carbon
monoxide gas. This dangerous gas, if breathed in suf¬
ficient concentrations, can cause unconsciousness or
even death. Install the exhaust system in strict compli¬
ance with applicable codes, standards and regula¬
tions. There must be no possibility for exhaust gases
entering the vehicle interior and endangering people
or animals.
A The generator set produces dangerously high electri¬
cal voltage. Contact with bare wires, bare terminals,
etc., will result in extremely hazardous and possibly
lethal electrical shock.
• All applicable electrical codes, standards and regula¬
tions must be strictly complied with in the installation
and use of this equipment.
• The generator must be properly grounded (bonded)
to the vehicle chassis or frame.
A If the vehicle electrical circuits can be powered by any
other source of electricity (such as a "dockside"
power receptacle), there must be no possibility of
connecting the different power sources to the vehicle
circuits at the same time. The "dockside" (utility)
power source must be positively isolated from the
vehicle circuits whenever the generator is operating.
Failure to isolate the vehicle circuits from the dock-
side power supply when the generator is running
may result in damage to the generator or serious
injury or death to dockside (utility) power workers
due to backfeed of electrical energy.
• Never work on the equipment while standing in
water, while barefoot, or while hands or feet are
wet. Dangerous electrical shock will result.
• Jewelry conducts electricity, which can cause danger¬
ous electrical shock. Remove all jewelry (such as rings,
watches, or bracelets) before working on this equip¬
ment.
• The generator requires an adequate flow of air for
cooling and ventilation. Without sufficient cooling air
flow, the engine-generator quickly overheats, which
causes serious damage to the generator, a fire or an
explosion. Generator air inlet and outlet openings
must be provided in strict compliance with the manu¬
facturer's recommendations.
• Never work on this equipment while physically or
mentally fatigued. Stay alert at all times.
Storage batteries give off EXPLOSIVE hydrogen gas
while charging. The battery used for cranking and
starting this generator should be installed in its own
ventecT compartment. Provide adequate ventilation
for the battery, to prevent explosive hydrogen gas
from accumulating.
• Never insert any tool or other object through open¬
ings in the generator interior, even if the unit is not
running. You might seriously injure yourself or dam¬
age the equipment.
• Staying alert and using "common sense" are major
measures for preventing accidents.

TABLE OF CONTENTS
GENERAL SAFETY RULES.inside cover
GENERAL INFORMATION
Purpose and Scope of Manual. 2
Safety. 2
Standards Booklets.. 2
Equipment Description ;. 2
Engine Generator Operating Speed. 2
Reconnection for Dual Voltage. 3
SPECIFICATIONS
Generator Specifications. 4
Engine Specifications. 4
Recommended Fuel. 4
Fuel Consumption. 4
Recommended Engine Oil. 4
LOCATION AND SUPPORT
Generator Location. 5
Generator Support.. 5
Suspended Mounting. 5
Generator Restraint. 6
Swing Mount Generator Tray.. 6
GENERATOR COMPARTMENTS
Compartment Size. 7
Compartment Construction. 7
Sound Insulation Materials. 8
Compartment Roor Cutouts. 8
Acoustics’. 8-9
COOLING AND VENTILATION AIR
Generator Air Flow. 1 0
Cooling Air Inlet Openings.10
Compensating for Restrictions. 1 1
Testing the Installation.11
GASOLINE FUEL SYSTEM.. 12
Fuel Tank.12
Generator Fuel Supply Line...,.12
PROPANE GAS FUEL SYSTEM.13
Parts Not Included in Fuel System.13
Some Important Considerations.13
Vapor Withdrawal.14
Primary Regulator. 1 4
Gaseous Carburetion. 1 4
Fuel Supply Lines.15
Excess Flow Valve.15
Leakage Tests.15
EXHAUST SYSTEM. 1 6
Mufflers and Spark Arrestors.16
Type of Exhaust System.16
Exhaust System Safety. 1 6 - 17
ELECTRICAL CONNECTipNS
Electrical Junction Box..18
Wiring.18
Generator AC Connections.18
Conduit.19
Ground Fault Circuit Interrupters.19
Power Supply Cord.19
Isolating Different Power Sources. 1 9 - 2 0
DUAL VOLTAGE RECONNECTION
Reconnection Procedure.21
BATTERY INSTALLATION
Recommended Battery. 2 2
Battery Cables.22
Battery Cable Connections.22
Battery Compartment. 2 2
POST INSTALLATION TESTS
Before Initial Start Up.. 2 3
Initial Start.23
Checking No-Load Voltage and Frequency.23
Testing Under-load.23 - 24
Adjusting No-Load Frequency.......24 -25
Voltage Regulator Adjustment.25
INSTALLATION CHECK LIST..26
ELECTRICAL FORMULAS.27
MAJOR FEATURES AND DIMENSIONS.28 - 29

GENERAL INFORMATION
---- ^
PURPOSE AND SCOPE OF MANUAL
These Installation Instructions have been prepared
especially for the purpose of familiarizing installers
and owners of the applicable equipment with the pro¬
duct's instailation requirements. Give serious consid¬
eration to all information and instructions in the
Manual, both for safety and for coritinued reliable
operation of the equipment.
Because of the different recreational vehicle models
and the variations between the models, it wouid be
extremely difficult, if not impractical, to provide
detailed instructions on every installation possibility.
For that reason, instructions and illustrations in this
manual are general in nature. Illustrations are not
intended to sen/e as detailed installation blueprints. ,
The installation should comply strictly with all applica¬
ble codes, standards and regulations pertaining to the
installation and use of this product. If any portion of this
manual appears to be in conflict with such codes, stan¬
dards or regulations, the applicable codes, standards
or regulations must take precedence over the manual.
SAFETY
Before handling, installing, operating or servicing this
equipment, be sure to read carefully the “Notice to
Installer'’ and “Safety Rules” at front of this manual.
Comply with all SAFETY RULES to prevent death,
personal injury or damage to equipment and/or prop¬
erty. Stress safety to all installers, operators and ser¬
vice technicians who work on this equipment.
STANDARDS BOOKLETS
Installation, use and servicing of this equipment
should comply strictly with published standards, as
well as the manufacturer’s recommendations. The fol¬
lowing standards booklets (latest revision) are avail¬
able from the sources indicated:
1. N F P A Standard 501C, “Standard for Recreational
Vehicles", available from the National Fire Protection
Association, Batterymarch Park, Quincy, MA 02269.
2. N F PA 70, “NFPA Handbook of the National Electric
Code", obtained from same address as Item 1.
3. ANSI C1-1975 and ANS1119.2-1975, available from the
American National Standards Institute, 1430 Broadway,
New York, NY 10018.
4. A NSI A119.2/NFPA 501C, available from the
Recreational Vehicle Association, 1896 Preston White
Drive, Reston, VA 22090.
5. California Administrative Code, Title 25, available from
the State of California, Documents Section, P.O. Box
1015, North Highlands, CA 95660.
6. C SA Electrical Bulletin 946, available from the Canadian
Standards Association, Housing and Constructions
Materials Section, 178 Rexdale Boulevard, Rexdale,
Ontario, Canada, M9W1R3.
EQUIPMENT DESCRIPTION
Instructions and information in this section pertain to
Generac “NP and “Q” air-cooled generators, more
specifically as listed below. These generators are
designed specifically for installing in recreational vehi¬
cles. They operate 120 volts, 1-phase, 60 Hertz, AC
electrical loads.
NOTE: All units, except the Q40G, may be recon¬
nected for a dual voltage output of 120/240 volts AC.
Series
Power (wattage)
Max. Rated Current
at 120V
Q-40G
4200
35.0
Q-55G/LP
5500
45.8
Q-70G/LP
7000
58.3
NP-50G
5000
41.6
NP-50LP
4500
37.5
NP-66G/LP
6600
55
ENGINE GENERATOR
OPERATING SPEED
The generator’s revolving field (rotor) is driven by a 4-
cycle engine through a puiley and drive train arrange¬
ment (Figure 1). The generator supplies 120/240
volts AC at 60 Hertz when the rotor is operating at
3600 rpm. The drive train arrangement allows the
engine to operate at a lower speed than the rotor.
Engine speed is held nearly constant by a mechani¬
cal, fixed speed governor as follows:
Series Q-40G.2570 rpm
Series Q-55G/LP ..,. 2570 rpm
Series NP-50G/LP .2570 rpm
Series NP-66G/LP .2700 rpm
Series Q-70G/LP..2570 rpm
Figure 1 — Typical Pulley and Drive Train
— 2 —

RECONNEaiON FOR DUAL VOLTAGE
You can reconnect the generators to supply a dual
voltage AC output, if desired. That is, units may be
reconnected to operate 120 and/or 240 volts, 1-
phase, 60 Hertz, AC loads. This is done by connect¬
ing the hwo stator AC power windings in series as it is
shown in Figure 2.
IMPORTANT: UNITS RECONNECTED FOR
120/240 VOLTS DUAL VOLTAGE OUTPUT WILL
NOT BE LISTED PER RVIA.
NOTE: The Q-40G can NOT be reconnected for a
dual voltage output of 120/240 volts AC.
Figure 2 — Reconnection for Dual Voltage Output
When reconnecting for dual voltage output, the
installer should replace the main circiut breakers
(CB1 and CB2) with a single adequately rated circuit
breaker. Rated maximum continuous load currents
are listed below:
• NP-50LP —18.8 AC amperes
• NP-50G — 20.8 AC amperes
• Q-55G/LP — 22.9 AC amperes
• NP-66G/LP — 27.5 AC amperes
• Q-70G/LP — 29.1 AC amperes
NOTE: This option is unavailabe on the Q40 model.
— 3 —

SPECIFICATIONS
GENERATOR SPECIFICATIONS
SERIES
Q-40G
NP-50G
NP-50LP
Q-55G/LP
NP-66G/LP
Q-70GA.P
Rotor RPM
3600
3600
3600
3600
3600
3600
Rotor Poles
2
2
2
2
2 2
Engine RPM
2570
2570
2570
2570
2700
2570
Wattage*
4200
5000
4500
5500
6600
7000
Voltage*
120
120
120
120
120
120
Rated Amps*
35
41.6V 37.5*
45.8*
.55*
58.3A
Phase
1
1
1
1
1 1
Frequency
60
60
60
60 Hertz
60 Hertz
60 Hertz
Weight
215 lbs.
207 lbs.
207lbs.
215 lbs.
213 lbs.
222 lbs.
Length
25 inches
Width
18.5 inches
Height
16.68 inches ■
All units, except Q-40G, are reconnectable to
120/240 volts, dual voltage output. When reconnect¬
ed for dual voltage, units are not listed per RVIA.
V Rated maximum continuous current at 240 volts is
20.8 amps.
t Rated maximum continuous current at 240 volts is
22.9 amps.
t Rated maximum continuous current at 240 volts is
27.5 amps.
A Rated maximum continuous current at 240 volts is
29.1 amps.
* Rated maximum continuous current at 240 volts is
18.8 amps.
ENGINE SPECIFICATIONS
Type of Engine
NP-50G/LP.1 Cylinder, 4 Cycle OHVI
NP-66G/LP, Q-70G/LP
Q-40G, Q-55G/LP.V-Twin, 4 Cycle OHVI
Number of Cylinders
Q-40G, Q-55G/LP, NP-66G/LP, Q-70G/LP.2
NP-50G/LP .1
Valve Configuration.Overhead Valves
Cooling Method .Air-Cooled
Rated Horsepower
NP-50G/LP . 1 3 at 3600 RPM
Q-40G.16 at 3600 RPM
Q-55G/LP .16 at 3600 RPM
NP-66G/LP .16 at 3600 RPM
Q-70G/LP .19 at 3600 RPM
Displacement
NP-50G/LP .363cc
Q-40G .480cc
Q-55G/LP.480CC
NP-66G/LP .480CC
Q-70G/LP.570CC
Compression Ratio.8.6 tol
Cylinder Block.Aluminum with cast iron sleeve
Type of Governor.Mechanical, fixed speed
Air Cleaner.Paper element with foam pre-cleaner
Starter.12 volts DC electric
Recommended Spark Plugs.Champion RC12YC
Spark Plug Gap.0.030 inch (0.8mm)
Oil Filter ..Generac Part No. 70185
Crankcase Oil Capacity .1.5 U.S. quarts
Battery Voltage.12 volts DC
Recommended Battery§
Amp-Hour Rating .70 amp-hour
Cold Cranking Amperes .360.
Cranking Current...100 DC amperes
Battery Ground..Negative (-)
§ If ambient temperature is usually below 32“F (O^C),
use a battery rated at 95 amp-hours and 450 cold¬
cranking amperes.
RECOMMENDED FUEL
For the gasoline-powered units: Use clean, fresh
UNLEADED gasoline with a minimum octane rating of
87. Leaded REGULAR grade gasoline is an accept¬
able substitute.
■ FOR GASEOUS FUEL-POWERED UNITS
Use clean, fresh commercial propane gas. The
optional LP gas system was designed for a VAPOR
WITHDRAWAL type system.
FUEL CONSUMPTION
Gasoline fuel system In U.S. gallons per hour:
% '
OF WATTS
1 SERIES 1
NP-50G Q-40G Q-55G
NP-66G Q-70G
25% 0.16
0.16 0.21
0.25
0.27
50^S^
0.32
0.32 0.42 0.50
0.54
75%
0.46
0.47 0.62
0.74 0.81
100% 0.63
0.63
0.83 0.99 1.08
RECOMMENDED ENGINE OIL
Use oil classified “For Service SP and having an SAE
viscosity rating of 10W-30. Engine crankcase oil
capacity is 1.5 U.S. quarts (1.6 liters).
— 4 —

LOCATION AND SUPPORT
GENERATOR LOCATION
The most desirable location for the generator set is
between the vehicle's main frame members However,
this is seldom possible. Most units must be installed
on the side of the vehicle and are difficult to reinforce.
Many recreational vehicles have been factory
equipped with an area for the generator set. Some
vehicles may even have a generator compartment,
provided by the vehicle manufacturer.
Plan the generator location based on the following;
• The generator set must be installed on a framework that
is part of the recreational vehicle, as outlined in the para¬
graph entitled “Generator Support.”
• The location must provide an access opening that is large
enough to permit generator removal (unless the genera¬
tor is to be removed from underneath the supporting
framework.
• The location must provide easy access to frequently ser¬
viced components, such as filters, oil drains, spark plugs
and other common maintenance parts.
• The location must provide sufficient room to allow mini¬
mum clearance of at least 1 inch between all sides and 1 •
1/2 inches on top of the generator. If sound insulation is
to be used on compartment walls and ceiling, the mini¬
mum recommended applies to the space between the
generator and such insulation.
• The location must provide adequate cooling and ventilat¬
ing air flow for the generator without a great deal of work
and expense.
GENERATOR SUPPORT
The generator must be securely attached to a metal
framework that has been made part of the vehicle
frame structure by bolting or welding. The metal
framework on which the generator will rest and which
will restrain the generator set should consist of at
least two horizontal beams. These beams should con¬
sist of (a) 1-1/2 inch square, 11 gauge steel tubing
OR (b) 1-1/2 inch, 11 gauge angle iron. A typical sup¬
porting frame with horizontal support tubing, is shown
in Figure 3.
The generator can be installed so that it sits on top of
the horizontal support tubing, if the vehicle design
permits. Another method is to suspend the generator
below the horizontal support tubing by means of suit¬
able, structurally sound metal framework. The follow¬
ing general rules apply:
• Vehicle construction MUST be capable of supporting the
weight of the generator.
• Whether the generator is mounted above the horizontal
support tubing or suspended below the tubing, the sup¬
porting frame used must be structurally sound.
• If the generator cannot be bolted directly to the support¬
ing frame or support tubing, consider using additional
tubing, angle brackets or other supports to give the sup¬
porting frame sufficient strength.
Figure 3 — Typical Horizontal Support Frame
SUSPENDED MOUNTING
If you are going to suspend the generator below the
horizontal support tubing, the suspension method you
use with the vehicle frame members must have the
following; (a) be able to support the weight of the gen¬
erator; and (b) provide sufficient restraint for the gen¬
erator. One typical suspended mounting system is
shown in Figure 4. The location of a suspended
mounting system must be carefully planned, keeping
the following general rules in mind:
• Protect the generator against road splash and debris.
Baffles or splash guards may be required to protect cer¬
tain areas of the generator. To make sure the generator is
adequately protected, road test the installation through
mud, water and slush.
Figure 4 — Typical Suspended Mounting System
• The installer must make certain the selected location will
permit adequate cooling and ventilating air flow to be
supplied.
— 5 —

GENERATOR RESTRAINT
Use four 3/8''-16 hardened steel bolts (Grade 5) to
fasten the generator to the supporting frame or the
support tubing. These bolts must pass through (a) the
generator mounting base, (b) the compartment floor,
if a compartment is used, and (c) the supporting
framework (Figure 5). All bolts must be long enough
so that when tight, at least 3 threads are visible past
the retaining lock nuts. Refer to “COMPARTMENT’
section for location of generator mounting holes.
SWING MOUNT GENERATOR TRAY
If you use a suspended mounting system, the installer
may wish to consider using the Generac Model 9164
Swing Mount Generator Tray, The Model 9164 tray
allows you to swing the generator downward and
away from the vehicle frame. This makes it simple to
remove the unit and have easy access to parts
(Figure 6).'
The tray on which the generator rests is hinged, per¬
mitting it to swing downward after two side support
rails and a center support rail are unbolted.
Instructions for tray installation are included with the
tray mounting kit.
— 6 —

GENERATOR COMPARTMENTS
The generator set may or may not be installed inside
a compartment that is constructed specifically for
housing a generator. This section applies to generator
compartments when they are installed. The following
general rules apply to compartments:
• The generator compartment should be either
constructed of, or lined with, 26 gauge galvanized
steel.
IMPORTANT: ALUMINUM IS NOT AN ACCEPT¬
ABLE ALTERNATIVE TO GALVANIZED STEEL.
DUE TO ALUMINUM'S LOW MELTING POINT.
• If the compartment is lined with galvanized steel,
it may be constructed of any material. Generac
recommends that the compartment be construct¬
ed of 1/2-inch thick plywood, with the floor made
of a double thickness of plywood for added
strength.
• All seams, splices and joints of the compartment
walls (unless vapor tight by design) should be
caulked.
IMPORTANT: CAULKING MUST BE DONE SO
THAT THE CAULKING MATERIAL WILL STAY IN
PLACE PERMANENTLY. PRESSING SUCH MATE¬
RIALS AS PUTTY TAPE ONTO JOINTS AND
SEAMS WILL NOT MEET THAT REQUIREMENT. A
HIGH QUALITY SILICONE RUBBER SEALANT IS
RECOMMENDED.
• Holes and openings through the compartment
walls for passage of electrical conduit, conduc¬
tors, etc, into vehicle living area must be sealed
vapor-tight with silicone rubber base sealant.
• If you use flexible metal conduit, seal the conduit
at the end where it terminates inside the junction
box. Flexible metal conduit is NOT vapor tight
along its entire length.
• Seams and joints of the galvanized steel
(whether used as a liner or the compartment
itself) must be lapped and mechanically secured.
Such seams may be manufactured, welded, bolt¬
ed, riveted, or screwed. Manufactured lock
seams are shown in Figure 7.
Fold Locked Off Set
Standing Double Lock Double Seam
Acme Lock Gordon Seam Lock Seam
COMPARTMENT SIZE
Plan the compartment size carefully. Provide a mini¬
mum of at least 1 inch of clearance between the gen¬
erator and compartment walls and 1-1/2 inch of clear¬
ance between the generator and the ceiling AFTER
you have lined the compartment with metal, and
AFTER you have installed sound insulation (Figure
8 ).
NOTE: Refer to the “Dimensions and Features” draw¬
ing in the back of this manual.
Figure 8 — Provide Clearance Around Generato
1 INCH (2.S4CM)
PLYWOOD MINIMUM CLEARANCE
L— INSULATION METAL LINING—^
COMPARTMENT CONSTRUaiON
• The generator compartment should be constructed of 1/2
inch thick plywood. Make the compartment floor a double
thickness of 1/2 inch plywood with the grain of the wood
at cross section for added strength (Figure 9).
Figure 9 — Typical Compartment Construction
• Line the entire compartment interior with 26 gauge galva¬
nized steel as described above.

• Line the exterior (underside) of the compartment floor
with 26 gauge galvanized steel.
• Vapor seal all compartment seams and joints, to prevent
poisonous, flammable or explosive vapors from entering
the vehiclef interior.
NOTE: Silicone rubber base sealant is an acceptable
caulking material. Pressing putty tape onto compart¬
ment joints and seams is NOT acceptable.
• After the compartment has been metal lined and vapor
sealed, line the compartment interior walls and ceiling
with an approved, non-flammable sound insulating mater¬
ial. See “Sound Insulating Materials.”
DANGER: DO NOT INSTALL SOUND INSULATION
OR ANY ABSORBENT MATERIAL ON THE COM¬
PARTMENT FLOOR INTERIOR. SUCH MATERIALS
WILL BECOME SOAKED WITH COMBUSTIBLE OR
EXPLOSIVE VAPORS AND LIQUIDS AND WILL
BECOME A FIRE HAZARD.
• Openings in compartment walls for passage of electrical
conduit, conductors, hoses, cables, etc., must be made
vapor tight with suitable caulking material.
• Flexible conduit must be sealed internally at the end
where it terminates inside a compartment's electrical
junction box.
NOTE: The preceding is required because flexible
conduit, due to its unique construction, is not vapor-
tight along its entire length.
DANGER: DO NOT INSTALL ANY FLAMMABLE
MATERIAL DIRECTLY ABOVE OR AROUND THE
COMPARTMENT. HEAT, TRANSFERRED THROUGH
THE COMPARTMENT STRUCTURE, MAY BE SUF¬
FICIENT TO IGNITE, CHAR OR DISCOLOR SEAT
CUSHIONS, FIBERBOARD AND OTHER FLAMMA¬
BLE MATERIALS. YOU MAY NEED TO USE
APPROVED NON-FLAMMABLE INSULATING
MATERIALS IN HIGH TEMPERATURE AREAS.
SOUND INSULATING MATERIALS
Once installers have determined that compartments
are properly constructed and metal lined, they can
add acoustical material. This may include additional
sealant or insulating material, to reflect noise away
from the vehicle interior.
Sound insulating materials should be of a non-flam¬
mable type. One excellent insulating material is a 1
inch thick fiberglass having a 2-pound density. When
fiberglass is used, its coated side should face toward
the compartment interior.
Using a combination of sound insulating materials can
often reduce noise more effectively than a single
material. For example, a sheet of lead or visco-elastic
material, along with a layer of other acoustical materi¬
al, is more effective than when a single material is
used.
COMPARTMENT FLOOR CUTOUTS
You rriust provide openings in the generator compart¬
ment for the following items (Figure 10):
• Engine exhaust and cooling air outlets
• Generator cooling air inlet
• Four holes for passage of generator mounting bolts. See
“Generator Restrainf on Page 6.
DANGER: FUEL UNES AND EXHAUST PIPING
MUST NOT PENETRATE INTO VEHICLE LIVING
AREA.
Figure 10 — Compartment Floor Cutout
If excessive noise levels should become a problem,
the installer may wish to consider the following:
• Using special sound insulating materials.
• Construction of a special noise abatement compartment.
IMPORTANT: ANY METHOD USED TO REDUCE
NOISE MUST NOT ADVERSELY AFFECT THE
FLOW OF COOLING AND VENTILATING AIR INTO
OR OUT OF THE COMPARTMENT.
o
— 8 —