Onan MGKBC Series User manual

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Installation
Manual
MGKBC, MGKBD
Printed in U.S.A. 02-04 981-0635B
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The engine exhaust from this product
contains chemicals known to the State
of California to cause cancer, birth
defects or other reproductive harm.
!!
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i
Table of Contents
SECTION PAGE
SAFETY PRECAUTIONS ii. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
THE HAZARDS OF CARBON MONOXIDE iv. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SPECIFICATIONS v. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INTRODUCTION 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Standards for Safety 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Outline Drawings 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LOCATION AND MOUNTING 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lifting the Genset 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Locating the Genset 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mounting the Genset 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VENTILATION 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ventilation Exhaust System 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Carbon Monoxide 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ignition Protection 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FUEL SUPPLY 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ENGINE COOLING 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling System Overview 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
System Components 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Raw Water Pickup Test 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ENGINE EXHAUST 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
System Components 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust Water Separator Backflow Test 10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ELECTRICAL CONNECTIONS 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Generator 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Remote Control 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Batteries 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DC Grounding 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
External Shutdown Devices 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CHANGING FREQUENCY AND ADJUSTING VOLTAGE 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing Frequency 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adjusting Voltage 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
INSTALLATION CHECKS AND STARTUP 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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ii
Safety Precautions
Electricity, fuel, exhaust, hot engine coolant, moving
parts and batteries present hazards which can re-
sult in severe personal injury or death.
Thoroughly read the OPERATOR’S MANUAL be-
fore operating the genset. Safe operation and top
performance can only be attained when equipment
is operated and maintained properly.
The following symbols in this manual alert you to po-
tential hazards to operators, service personnel and
equipment.
DANGER alerts you to an immediate hazard
that will result in severe personal injury or
death.
WARNING alerts you to a hazard or unsafe
practice that can result in severe personal injury
or death.
CAUTION alerts you to a hazard or unsafe
practice that can result in personal injury or
equipment damage.
GENERAL PRECAUTIONS
•Keep children away from the genset.
•Do not step on the genset when entering or
leaving the generator room. Parts can bend or
break leading to electrical shorts or to fuel, cool-
ant or exhaust leaks.
•To prevent accidental or remote starting while
working on the genset, disconnect the nega-
tive (−) battery cable at the battery.
•Let the engine cool down before removing the
coolant pressure cap or opening the coolant
drain. Hot coolant under pressure can spray
and cause severe burns.
•Do not use evaporative starting fluids such as
ether. They are highly explosive.
•Keep the genset, drip pan and compartment
clean. Oily rags can catch fire. Gear stowed in
the compartment can cause the genset to over-
heat.
•Make sure all fasteners are secure and proper-
ly torqued.
•Do not work on the genset when mentally or
physically fatigued or after having consumed
alcohol or drugs.
•You must be trained and experienced to make
adjustments while the genset is running—hot,
moving or electrically live parts can cause se-
vere personal injury or death.
•Used engine oil has been identified by some
U. S. state and federal agencies as causing
cancer or reproductive toxicity. Do not ingest,
inhale, or contact used oil or its vapors.
•Benzene and lead in some gasolines have
been identified by some U. S. state and federal
agencies as causing cancer or reproductive
toxicity. Do not to ingest, inhale or contact gaso-
line or its vapors.
•Ethylene glycol, used as engine antifreeze, is
toxic to humans and animals. Clean up spills
and dispose of used engine coolant in accor-
dance with local environmental regulations.
•Keep USCG Approved multi-class ABC fire ex-
tinguishers on the boat. Class A fires involve or-
dinary combustible materials such as wood
and cloth; Class B fires, combustible and flam-
mable liquid fuels and gaseous fuels; Class C
fires, live electrical equipment. (ref. NFPA
No. 10)
•Genset installation and operation must comply
with all applicable local, state and national
codes and regulations.
POST THESE SUGGESTIONS IN POTENTIAL HAZARD AREAS OF THE BOAT
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iii
GENERATOR VOLTAGE IS DEADLY
•Generator electrical output connections must
be made by a trained and experienced electri-
cian in accordance with applicable codes.
•When the boat has provisions for connection to
shore power, the genset must be connected to
the boat electrical system through an approved
transfer switch to prevent backfeed. Backfeed
can lead to electric shock resulting in severe
personal injury or death.
•Use caution when working on live electrical
equipment. Remove jewelry, make sure cloth-
ing and shoes are dry, stand on a dry wooden
platform or rubber insulating mat and use tools
with insulated handles.
ENGINE EXHAUST IS DEADLY
•Never sleep in a boat while the genset is run-
ning unless the cabin is equipped with a proper-
ly working carbon monoxide detector-alarm.
•Inspect for exhaust leaks at every startup and
after every eight hours of operation.
•The exhaust system must be installed in accor-
dance with the genset Installation Manual.
•When modifying or repairing the boat, care
must be taken to maintain sealing of the living
quarters from spaces where exhaust gas can
accumulate.
•The ventilation exhaust blowers must be kept
in good working order to prevent the accumula-
tions of engine exhaust.
•For more information about the hazards of car-
bon monoxide see American Boat and Yacht
Council (ABYC) publication TH-22—Educa-
tional Information About Carbon Monoxide.
GASOLINE IS FLAMMABLE AND
EXPLOSIVE
•Do not smoke where fuel vapors are present or
in areas sharing ventilation with fuel tanks, en-
gines and other such equipment. Keep flames,
sparks, pilot lights, electrical switches, arc-pro-
ducing equipment and all other sources of igni-
tion well away.
•All electrical devices, such as switches, circuit
breakers, meters and control panels used in
areas where gasoline vapors can accumulate
must be Ignition Protected.
•No substitutes are permitted for the parts listed
in the Critical Parts Index of the genset Parts
Catalog. They must be purchased from Onan
and be installed in accordance with the genset
Service Manual by those who are trained and
experienced in marine gasoline genset service.
•Fuel lines must be secure, free of leaks and
separated or shielded from electrical wiring.
•When modifying or repairing the boat, care
must be taken to maintain sealing of the living
quarters from spaces where gasoline vapors
can accumulate.
•The ventilation exhaust blowers must be kept
in good working order to prevent the accumula-
tions of gasoline vapors.
BATTERY GAS IS EXPLOSIVE
•Do not smoke near batteries.
•Wear safety glasses while servicing batteries.
•To reduce arcing when disconnecting or recon-
necting battery cables, always disconnect the
negative (−) battery cable first and reconnect it
last.
MOVING PARTS CAN CAUSE SEVERE
PERSONAL INJURY OR DEATH
•Do not wear jewelry or loose clothing near mov-
ing parts such as PTO shafts, fans, belts and
pulleys.
•Keep hands away from moving parts.
•Keep guards in place over fans, belts, pulleys,
and other moving parts.
POST THESE SUGGESTIONS IN POTENTIAL HAZARD AREAS OF THE BOAT
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iv
The Hazards of Carbon Monoxide
Most people know not to run a car in the garage.
Many people know about the threat of carbon mon-
oxide poisoning in the house. But few people are
aware that this invisible killer is even more insidious
aboard a boat.
Engine-driven generators can produce harmful lev-
els of carbon monoxide that can injure or kill you.
The nature of boating is such that you can be
harmed by this poisonous gas despite good genera-
tor set maintenance and proper ventilation.
WHAT IS CARBON MONOXIDE
POISONING?
Carbon Monoxide (CO) is an odorless and colorless
gas. You cannot see it or smell it. Red blood cells,
however, have a greater affinity for CO than for Oxy-
gen. Therefore, exposure even to low levels of CO
for a prolonged period can lead to asphyxiation (lack
of oxygen) resulting in death. Mild effects of CO poi-
soning include eye irritation, dizziness, headaches,
fatigue and the inability to think clearly. More ex-
treme symptoms include vomiting, seizures and col-
lapse.
WHAT ARE THE SPECIAL RISKS OF CO
ON BOATS?
Depending on air temperature and wind, CO can ac-
cumulate between hulls, under an overhanging
deck or rear swimming platform and in and around
the boat. A swimmer can be exposed to lethal levels
of CO when the genset is running. Passengers on
deck and in the living quarters can also be exposed,
especially when the boat is docked, beached or tied
to a neighboring boat.
The risk of exposure to CO can be multiplied greatly
by the “station wagon” effect, obstructions that block
exhaust dissipation, and infiltration from neighbor-
ing boats. To protect against all three situations,
Onan recommends that reliable CO detector-
alarms be installed on your boat.
•The Station Wagon Effect − A boat pushes
aside the air through which it is moving, causing
a zone of low pressure in the back of the boat
and cabins into which exhaust gases can be
drawn (see figure). A breeze across an an-
chored boat can have the same effect. Opening
doors and windows so that air can flow through
the boat can reduce the effect.
•Obstructions − Anchoring near a large object
such as a boat house or sea wall or in a con-
fined space such as a canyon can cause ex-
haust gases to accumulate in and around the
boat despite good generator set maintenance
and proper ventilation. Don’t run the generator
set when anchored in such places.
•Exhaust from Neighboring Boats − When
boats are anchored in close quarters exhaust
from neighboring boats can accumulate in and
around yours.
ONLY YOU CAN PROTECT YOURSELF
FROM CO POISONING!
•Watch constantly for swimmers when the gen-
erator set is running.
•Make sure exhaust cannot get under the deck,
between hulls or enter the living quarters
through a window, vent or door.
•Make sure all CO detectors are working.
•Pay attention to the signs of CO poisoning.
•Check the exhaust system for corrosion, ob-
struction and leaks each time you start the gen-
erator set and every eight hours if you run it
continuously.
POST THESE SUGGESTIONS IN POTENTIAL HAZARD AREAS OF THE BOAT
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v
Specifications
MGKBC MGKBD
GENERATOR: Two-Bearing, 2-Pole Rotating Field, Microprocessor Regulated. See Genset Nameplate for Rating
FUEL CONSUMPTION:
60 Hz: Full Load
Half Load
1.59 gph (6.0 liter/hr)
0.95 gph (3.6 liter/hr)
1.4 gph (5.3 liter/hr)
0.77 gph (2.9 liter/hr)
50 Hz: Full Load
Half Load
1.4 gph (5.3 liter/hr)
0.77 gph (2.9 liter/hr)
−
−
Engine/Generator Speed: 60 Hz
50 Hz
2900/3600 rpm
2400/3000 rpm
2400/3600 rpm
−
ENGINE: 4-Stroke Cycle, Spark-Ignited, Water Cooled, Microprocessor Governed (Isochronous)
Number of Cylinders 3 3
Bore 2.68 inch (68 mm) 2.68 inch (68 mm)
Stroke 2.68 inch (68 mm) 2.68 inch (68 mm)
Displacement 45.2 inch3(740 cm3)45.2 inch3(740 cm3)
Compression Ratio 9.2:1 9.2:1
Firing Order (Clockwise Rotation) 1-2-3 1-2-3
Ignition Timing 18°BTDC 18°BTDC
Spark Plug Gap 0.039 − 0.043 inch (1.0 − 1.1 mm) 0.039 − 0.043 inch (1.0 − 1.1 mm)
Valve Lash (cold) 0.0059 − 0.0073 inch (0.145 − 0.185 mm) 0.0059 − 0.0073 inch (0.145 − 0.185 mm)
Engine Oil Capacity 2.0 quart (1.9 liter) 2.0 quart (1.9 liter)
Engine Oil Drain Connection 3/8 NPT 3/8 NPT
Coolant Capacity 3.3 quart (3.1 liter) 3.3 quart (3.1 liter)
Coolant Flow: 60 Hz
50 Hz
3.5 gpm (13 liter/min)
3.0 gpm (16 liter/min)
3.5 gpm (13 liter/min)
−
Raw Water Flow: 60 Hz
50 Hz
5.0 gpm (19 liter/min)
4.0 gpm (15 liter/min)
5.0 gpm (19 liter/min)
−
Maximum Raw Water Pump Lift 4 feet (1.2 m) with 5/8 inch ID hose 4 feet (1.2 m) with 5/8 inch ID hose
Raw Water Inlet Connection 5/8 inch (15.9 mm) ID Hose 5/8 inch (15.9 mm) ID Hose
Maximum Fuel Pump Lift 4 feet (1.2 m) with 1/4 inch ID fuel line 4 feet (1.2 m) with 1/4 inch ID fuel line
Required Fuel Line Size 1/4 inch (6.4 mm) ID 1/4 inch (6.4 mm) ID
Fuel Supply Connection 1/8 NPT female 1/8 NPT female
Wet Exhaust Outlet Connection 2.0 inch (50.8 mm) ID Hose 2.0 inch (50.8 mm) ID Hose
Maximum Exhaust Back Pressure 3 inch (76 mm) Hg 3 inch (76 mm) Hg
Combustion Air Flow: 60 Hz
50 Hz
32 cfm (0.91 m3/min)
26.7 cfm (0.76 m3/min)
26.7 cfm (0.76 m3/min)
−
Generator Cooling Air: 60 Hz
50 Hz
100 cfm (2.83 m3/min)
80 cfm (2.26 m3/min)
100 cfm (2.83 m3/min)
−
BATTERIES:
Nominal Battery Voltage 12 volts 12 volts
Minimum CCA Rating 360 amps 360 amps
Battery Charging Output (Optional) 3 amps 3 amps
SIZE, WEIGHT, NOISE:
Size: L x W x H 26.6 x 23 x 21.1 inch
(676 x 583 x 535 mm)
26.6 x 23 x 21.1 inch
(676 x 583 x 535 mm)
Weight (dry) 425 lbs (193 kg) 425 lbs (193 kg)
Noise (Full Load @ 1 m): 60 Hz
50 Hz
71 dB(A)
69 dB(A)
69 dB(A)
−
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vi
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1
Introduction
This genset is suitable for installation in accordance
with USCG Pleasure Craft Regulations and ISO
Small Craft Standards.
A generator set (genset) must be installed properly
to attain safe, reliable and quiet operation. Read
through this manual completely before starting the
installation. It is a guide only. You must decide how
to address the particular concerns of the installa-
tion.
Decisions you have to make will concern:
•Location and mounting
•Engine exhaust discharge and silencing
•Engine cooling
•Genset compartment ventilation
•Selection of Ignition Protected devices for
areas where gasoline vapors can accumulate
•Preventing the migration of exhaust gases and
gasoline vapors into the living quarters
•Fuel connections
•Batteries
•Electrical connections
•Bonding for grounding
•Accessibility for operation and maintenance
•Noise and vibration.
See the Operator’s Manual for operation and main-
tenance and the Service Manual for service.
Note: Manuals are updated from time-to-time to re-
flect changes in the equipment and its specifica-
tions. For this reason, only the copy of the installa-
tion manual supplied with the genset should be used
as a guide for the installation.
STANDARDS FOR SAFETY
You must find out which standards for safety are ap-
plicable. Compliance with United States Coast
Guard (USCG) regulations is mandatory for boats in
U. S. waters. The American Boat and Yacht Council
(ABYC) and the National Fire Protection Associa-
tion (NFPA) are typical of agencies that publish
safety standards for the construction and installa-
tion of marine equipment. It is suggested that you
obtain the following standards:
•USCG regulations are under Titles 33 and 46 of
the Code of Federal Regulations (CFR),
U.S. Government Printing Office
Washington, D.C. 20404.
•NFPA No. 302, Pleasure and Commercial Mo-
tor Craft,
National Fire Protection Association
Batterymarch Park
Quincy, MA 02269
•Standards and Recommended Practices For
Small Craft,
American Boat and Yacht Council, Inc.
P.O. Box 747
Millersville, MD 21108
Particular attention should be paid to ABYC P-1,
Installation of Exhaust Systems for Propulsion and
Auxiliary Machinery; ABYC E-8, Alternating Current
(AC) Electrical Systems on Boats; and ABYC E-9,
Direct Current (DC) Electrical Systems on Boats.
OUTLINE DRAWINGS
See OUTLINE DRAWING (Page 23) for installa-
tion details: mounting bolt hole locations, connec-
tion points (fuel, battery, raw water, exhaust, remote
control and AC output), sizes and types of fittings,
weight, overall dimensions, etc. See your Onan
dealer to obtain a large-scale copy of the drawing.
WARNING Improper installation can result in
severe personal injury or death and damage to
equipment. The installer must be trained and ex-
perienced in the installation of marine gasoline
gensets.
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2
Location and Mounting
LIFTING THE GENSET
The genset weighs 425 pounds (193 kg) and has
two lifting eyes accessible through the round covers
in the top panel (Page 23). Use proper equipment
for safe handling. Use both lifting eyes.
Save the four steel clamps that secured the genset
to the shipping skid if they are to be used for secur-
ing the genset to the floor or frame. See MOUNT-
ING THE GENSET.
LOCATING THE GENSET
See the other sections titled Ventilation, Fuel Sup-
ply, Engine Cooling and Engine Exhaust for addi-
tional considerations that bear on location.
The genset is ignition protected and therefore per-
mitted under USCG regulation 33CFR183 to be lo-
cated in a gasoline fuel environment.
Because of noise, vibration, exhaust and vapors,
the generator compartment should be located as far
from the living quarters as practical.
Locate the genset where there will be enough room
to perform periodic maintenance and service. Non-
service sides should have at least 2 inches (51 mm)
of clearance. The left side must have at least 1 inch
(25 mm) of clearance for inlet air flow. The top must
have at least 2 inches (51 mm) of clearance for re-
moval. The right side must have at least 2 inches
(51 mm) of clearance for removing the side panel,
which must be remove to adjust the V-belt, replace
the raw water pump impeller, service the heat ex-
changer and replace the fuel pump. At least 1 inch
(25 mm) of clearance is required in front of the outlet
air grille on the right side.
There must be access for:
•Starting and stopping the genset
•Resetting the line circuit breakers
•Checking, filling and draining engine oil
•Changing the engine oil filter
•Checking, filling and draining engine coolant
•Replacing raw water and exhaust hoses
•Replacing the raw water pump impeller
•Adjusting the V-belt
•Replacing the fuel pump
•Inspecting the drive belt system and generator
bearing at the back of the genset
•Making fuel connections
•Making battery and ground connections
•Making AC connections
•Making remote control connections
MOUNTING THE GENSET
The genset has integral vibration isolators. The sup-
porting structure underneath should be level and
able to support the weight of the genset. Floor or
frame stiffness should be greatest under the vibra-
tion isolators. Secure the genset to the floor or frame
in one of the following ways:
•By bolting it with three (3) bolts through the bolt
holes in the drip pan (Page 23).
•By clamping it with the four (4) steel clamps that
secured it to the shipping skid: one at each cor-
ner (Page 23). A clamp can be on either side
of a corner.
•By bolting it through the front bolt hole in the
drip pan and clamping each rear corner with a
steel clamp.
To reduce noise, plug the unused clamp openings in
the drip pan with the four rubber plugs shipped in the
literature packet.
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3
Ventilation
WARNING EXHAUST GAS IS DEADLY—GAS-
OLINE VAPORS ARE EXPLOSIVE! Failure to
provide proper ventilation can result in asphyxi-
ation, fire and explosion. The ventilation system
must meet applicable standards and regula-
tions, including those of the USCG, ABYC and
NFPA.
VENTILATION EXHAUST SYSTEM
The USCG requires the genset be open to the atmo-
sphere or be ventilated by an exhaust blower sys-
tem to prevent dangerous concentrations of gaso-
line vapors and exhaust.
Exhaust Blower System Capacity
Each exhaust blower or combination of blowers
must be rated at an air flow capacity not less than
that computed by the formulas in Table 1.
TABLE 1. EXHAUST BLOWER CAPACITIES (USCG)
NET
COMPARTMENT
VOLUME (V)
(Cubic Feet)
MINIMUM
BLOWER
RATING
(CFM)
MINIMUM
SYSTEM
OUTPUT
(CFM)
Smaller than 34 50 20
Between 34 and 100 V x 1.5 V x 0.6
Larger than 100 (V ÷2) + 100 (V x 0.2) + 40
V = Net volume of genset compartment and compartments
open thereto. CFM = Cubic Feet per Minute.
Warning Labels
To remind the boat operator to turn on the ventilation
exhaust system before starting the genset, a label
must be affixed next to each genset starting switch,
to the effect that:
WARNING Gasoline vapors can explode. Be-
fore starting the genset, operate the exhaust
blower for 4 minutes and check the genset
compartment and bilge for gasoline vapors.
Ventilation Ducts
Ventilating air should enter near the bottom of the
compartment at the left side, near the air inlet
(Page 23), and exit near the top at the right side.
This will promote natural convective air flow, good
air exchange and fresh air for combustion and gen-
erator cooling when the exhaust blower system is
not running.
Ventilation Air Inlets
The free-air area of a ventilation air inlet should be at
least twice that of the duct. Use 40 in2(258 cm2) as
the basis for calculating inlet and outlet air duct
sizes and areas for screens and louvers. Do not use
flush air inlets or louvered transom outlets, which
are easily blocked. Means must be provided to keep
out sea spray.
Ventilation for Cooling
Ventilation is also necessary for genset cooling, es-
pecially just after the boat has been under way. Op-
erating a genset in ambient temperatures above
104°F (40°C) will result in noticeable loss of power.
Operating a genset in ambient temperatures higher
than 122°F (50°C) will reduce the life of electrical
components, generator windings, rubber and other
construction materials.
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4
CARBON MONOXIDE
CO Detector-Alarms
Carbon monoxide (CO) detector-alarms, listed for
marine applications, must be installed in the living
quarters of the boat. Wind shifts, boat motion, ex-
haust from other boats at dockside and other condi-
tions can cause exposure to harmful concentrations
of carbon monoxide even when proper ventilation is
provided and living quarters are sealed off from en-
gine rooms.
Openings and Feed-Through Holes in
Decks and Bulkheads
All openings and feed-through holes in decks and
bulkheads for wiring, conduit, pipe and hose must
be sealed to prevent exhaust gases and gasoline
vapors from entering the rest of the boat. Wiring
conduit must be sealed inside as well as outside.
Plumbing Fixtures
Cabin plumbing drains must have approved traps to
prevent the entrance of exhaust gases from outside.
IGNITION PROTECTION
The genset is ignition protected and therefore per-
mitted under USCG regulation 33CFR183 to be lo-
cated in a gasoline fuel environment.
All electrical devices, such as switches, circuit
breakers, meters and control panels used in areas
where gasoline vapors can accumulate must be
Ignition Protected.
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5
Fuel Supply
WARNING Gasoline is highly flammable and
explosive and can cause severe personal injury
or death. Fuel tank construction, location,
installation, bonding for grounding, ventilation,
piping, inspection and leak testing must be in
accordance with applicable standards and reg-
ulations, including those of the USCG, ABYC,
and NFPA.
Fuel
See the Operator’s Manual for recommended fuel.
Fuel Inlet Fitting
A 1/8 NPT fuel inlet fitting is mounted on the drip pan
on the right side (Page 23).
Fuel Lines and Hoses
Use USCG TYPE A1 fuel hose. Fuel lines and
hoses must have an inside diameter of 1/4 inch
(6.4 mm).
Do not connect the genset to a shared fuel distribu-
tion manifold. The genset fuel pump might not be
able to prime the fuel manifold nor overcome the
draw of a propulsion engine fuel system.
Use non-conductive fuel lines for connections at the
genset to prevent the fuel lines from carrying crank-
ing currents back through the fuel tank. Fuel tanks
are required to be bonded to the common nega-
tive (−) grounding system of the boat.
WARNING Fuel lines must not carry cranking
currents, which can cause fire resulting in se-
vere personal injury or death. Use non-conduc-
tive fuel lines for connections at the genset.
Fuel Filter
A fuel filter is installed at the inlet to the carburetor.
An external in-line fuel filter is provided in the litera-
ture packet. The filter must be readily accessible for
regular replacement and be install as close as pos-
sible to the genset.
Fuel Pickup
Provide a separate pickup tube in the fuel tank for
the genset. The inside diameter should be 1/4 inch
(6.35 mm). It must not be greater than 3/8 inch
(9 mm). In a common fuel supply tank, the genset
pickup tube should be shorter than those for the pro-
pulsion engines so that the genset cannot empty the
fuel tank.
Maximum Fuel Pump Lift
The genset fuel inlet fitting must not be more than
48 inches (122 cm) higher than the bottom of the
fuel pickup tube. The suction required at the genset
fuel inlet to overcome lift and line flow resistance (in-
cluding fittings, filters and valves) must not exceed
3 inches Hg (10 kPa).
Fuel Anti-Siphon Device
If any part of the fuel line is routed below the top of
the fuel tank, a fuel anti-siphon device must be
installed at the tank fitting to prevent accidental dis-
charge of gasoline.
Check Valve-Type Anti-Siphon Devices: A fuel
check valve used as an anti-siphon device must not
require a pull-off vacuum of more than 1.6 inches
Hg (5.5 kPa).
Solenoid-Type Anti-Siphon Devices: The genset
wiring harness has leads with quick-connect termi-
nals labeled SWB+ and CUSTOMER GND
(Page 21) that can be connected to power a pilot
relay for a fuel solenoid stop valve at the fuel tank
fitting. They are accessible by removing the access
cover on the left end of the genset (Page 23). The
total load on SWB+ must not exceed 0.5 amps.
Note: The genset leaves the factory with SWB+ jump-
ered to two other connectors, ESTOP and CO. When
making connections for a fuel solenoid pilot relay,
SWB+ must continue to be jumpered to ESTOP and
CO unless they are connected to normally closed ex-
ternal shutdown devices (Page 18), otherwise the
genset will not run.
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6
Engine Cooling
COOLING SYSTEM OVERVIEW
Refer to Figure 1. The engine is cooled by a pres-
surized, closed-loop liquid cooling system. Coolant
is pumped through passages in the engine block,
head and exhaust manifold. The exhaust manifold
also serves as the engine coolant reservoir.
The heat exchanger is mounted inside the exhaust
manifold. Raw water (the flotation water) is pumped
through tubes in the heat exchanger to cool the en-
gine coolant and then is passed through a hose into
the exhaust-water mixer to cool the exhaust gases.
The raw water is expelled from the boat along with
the exhaust gases. The V-belt drives the coolant
and the raw water pumps.
RAW
WATER IN
EXHAUST &
RAW WATER
OUT
THERMOSTAT
HOUSING
BLOCK
DRAIN CAP
RAW WATER
PUMP PULLEY
COOLANT
RAW WATER
EXHAUST-WATER
MIXER WITH HIGH
TEMPERATURE
EXHAUST SWITCH
RAW WATER FLOW
SENSOR
HOSE BARB TO
CONNECT COOLANT
RECOVERY TANK
EXHAUST MANIFOLD &
COOLANT RESERVOIR
PRESSURE CAP &
COOLANT FILL NECK
COOLANT
PUMP PULLEY
INSULATED
GASOLINE
HOSE
WHEN REQUIRED,
REMOVE THIS HOSE
AND CONNECT A
SIPHON BREAK
(PAGE 7)
DISCONNECT THE
RAW WATER PICKUP
HOSE HERE FOR THE
RAW WATER PICKUP
TEST (PAGE 8)
FIGURE 1. ENGINE COOLING SYSTEM
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7
SYSTEM COMPONENTS
Raw Water Pump
The raw water pump can work against a maximum
lift (suction) of 48 inches (122 cm) WC to deliver the
required flow of cooling water. Lift is a combination
of the actual vertical lift and the resistance to flow
cause by the hose, strainer, sea cock and through-
hull fitting.
The pump impeller must be wetted with water to es-
tablish initial pump lubrication and suction. See the
Operator’s Manual.
Raw Water Hose
The 5/8 inch (15.9 mm) hose barb for raw water
pickup is mounted on the drip pan on the right side
(Page 23). Use SAE 20R3 or equivalent hose to
supply raw water to the genset. The hose must be
able to resist a slight vacuum.
Sea Water Strainer
The sea water strainer should have a 5/8 inch
(15.9 mm) inlet. It should be located below the level
of the raw water pump (Page 23) and as close as
possible to the genset. The basket must be remove-
able for cleaning.
Sea Cock
Install a bronze, full-flow sea cock on the through-
hull fitting.
Through-Hull Fitting and Strainer
The through-hull fitting should have a 5/8 inch (15.9
mm) inlet and be as close to the genset as possible.
If the strainer has slotted openings, the slots must
be parallel to the keel for best flow when the boat is
under way. Also, stagger the through-hull fittings
along the keel so that downstream fittings are not
starved.
CAUTION Do not use a scoop-type through-
hull fitting. A forward-facing scoop can develop
enough ram pressure to flood the engine. A
rear-facing scoop can develop enough suction
to impede flow.
Siphon Break
Conduct the RAW WATER PICKUP TEST to deter-
mine whether a siphon break is required to prevent
the engine from being flooded with floatation water.
Siphon Break Kit 541-0876 is available if a siphon
break is required. Carefully follow the instructions in
the kit. The hoses in the kit replace the hose be-
tween the engine heat exchanger and exhaust-wa-
ter mixer (Figure 1). The end panel of the genset
has knockouts for the hoses to pass through
(Page 23). The kit has the hole grommets. Fig-
ures 4 and 5 illustrate typical siphon break installa-
tions.
CAUTION Engine damage due to flooding as a
result of failing to install a required siphon break
is not covered by Warranty.
Coolant Recovery Tank
The genset is shipped with a coolant recovery tank
kit. Follow the instructions in the kit. The tank must
be accessible for daily inspection and refilling.
Clamp the recovery hose to the hose barb on the
coolant fill neck (Figure 1). Route the tank recovery
and overflow hoses through the holes in the end of
the enclosure (Page 23). Make sure the overflow
hose terminates in the drip pan where it will not
splash coolant on electrical components. Fill the
tank in accordance with the Operator’s Manual.
Initial Coolant Fill
The genset is normally shipped from the factory with
coolant, unless prohibited by shipping regulations.
Fill the system, if necessary, in accordance with the
Operator’s Manual.
CAUTION Engine damage due to running the
engine without coolant is not covered by War-
ranty.
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8
RAW WATER PICKUP TEST
Objective
The objective is to determine the elevation of the
water line relative to the genset under all anticipated
uses and speeds of the boat.
Method
When the boat is ready for its sea trials and loaded
to its maximum rated capacity:
1. Close the sea cock and disconnect the raw wa-
ter pickup hose from the genset (Figure 1). Al-
ternatively, connect a clear plastic hose to the
strainer or sea cock.
2. Raise the end of the hose above expected wa-
ter level and open the sea cock. The water line
is at the level visible in a clear plastic hose or
where water just begins to spill as the end of the
hose is lowered. While the boat is still docked,
mark the level on the genset enclosure.
3. Operate the boat through its speed range, for-
ward and reverse. While the boat is operating,
have someone monitor the water level in the
hose and mark the highest level on the genset.
Requirement
A siphon break must be installed if the engine ex-
haust-water mixer (Page 23) is not at least 6 inches
(152 mm) above both water lines (docked and mov-
ing).
Note: If the water line when the boat is moving is
much higher than when the boat is docked, the differ-
ence could be due to the through-hull fitting or its
location. If the through-hull fitting is of the forward-
facing scoop-type designed to create ram pressure,
replace it with a flush-type fitting. Another possibility
might be to move the fitting to a location where the
dynamic hull pressure is less.
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9
Engine Exhaust
SYSTEM COMPONENTS
WARNING EXHAUST GAS IS DEADLY! The ex-
haust system must be leak-free and convey all
exhaust outside the boat, away from windows,
doors and vents.
Figures 2 and 3 illustrate typical exhaust systems
where the exhaust-water mixer is above the load
water line and Figures 4 and 5 where it is below.
See Engine Cooling (Page 6) regarding raw water
connections. The installation must comply with ap-
plicable standards and regulations, including those
of the USCG and ABYC.
Mufflers, water separators, resonators and siphon
breaks are available as kits from Onan. Muffler kits
include a strainer for the through-hull fitting.
Fitting and Hose Diameters
No fitting or hose section in the exhaust system may
have a smaller inside diameter than the genset ex-
haust outlet. Exhaust back pressure must be mea-
sured if the total run of the exhaust system is more
than 20 feet (6 meters). Use larger diameter hose if
back pressure exceeds 3 inches Hg (10 kPa).
Exhaust Hose
Use hose that has been approved for wet exhaust
systems. Approved hose and stainless steel el-
bows are available from Onan. Horizontal runs of
hose must slope down at least 1/2 inch per foot
(42 mm/meter) and be supported such that there
are no sags. The entire run of hose must be accessi-
ble for regular, visual inspections and replacement.
Hose Clamps
Use two 1/2 inch (12.7 mm) wide stainless steel
hose clamps to clamp each end of each hose.
Muffler
Install the muffler as close a practical to the engine,
observing the following:
1. The length of hose between the genset and the
muffler should be 1 to 5.5 feet (30 to 170 cm).
2. The muffler inlet must be more than 1 foot
(30 cm) below the exhaust-water mixer
(Page 23).
3. The muffler outlet hose must rise straight up
from the muffler into a water separator (Fig-
ures 2 and 4) or elbow that turns sharply down
(Figures 3 and 5).
4. When a water separator is use, the base of the
muffler should not be more than 54 inches
(1.4 meter) below the top of the water separa-
tor (Figure 2 or 4 ). When an elbow is used, the
base of the muffler should not be more than
48 inches (1.2 meter) below the elbow (Fig-
ure 3 or 5).
5. The muffler must be mounted such that air can
circulate underneath to prevent condensation
and mold.
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10
Exhaust Water Separator
When an exhaust water separator is used (Figure 2
or 4), the muffler outlet and water separator inlet di-
ameters must be the same size. The water separa-
tor should be installed directly above the muffler to
maintain a vertical lift. The through-hull fitting for the
drain hose should be below the load water line and
must have a sea cock. An EXHAUST WATER SEP-
ARATOR BACKFLOW TEST must be conducted
during the sea trials to determine that there is no
backflow that could flood the engine.
Exhaust Through-Hull Fitting
The exhaust through-hull fitting must be above the
load water line under all anticipated uses and
speeds of the boat. To reduce wave wash-in when a
water separator is used (Figure 2 or 4), the top of
the water separator must be at least 18 inches
(450 mm) above the load water line. When an elbow
is used at the top of the muffler outlet hose, the el-
bow must be at least 12 inches (305 mm) above the
through-hull fitting (Figure 3 or 5).
CAUTION Backflow can cause major engine
damage if the cylinders become flooded. The
sea trials must verify that there is no backflow
through either the exhaust hull fitting or the wa-
ter separator drain hose fitting.
Other Engine Exhaust Systems
Do not “T” into any other engine exhaust system.
Run the genset exhaust piping all the way to the hull
and terminate it flush with or extended slightly from
the outside of the hull.
CAUTION Corrosive exhaust vapors can mi-
grate through a shared exhaust system and
cause damage to idle engines. Provide a sepa-
rate exhaust system for each engine.
EXHAUST WATER SEPARATOR
BACKFLOW TEST
Objective: To determine that there is no backflow
through the exhaust water separator under any op-
erating condition (Figure 2 or 4).
Method: Conduct this test during the sea trials in
conjunction with the RAW WATER PICKUP TEST.
Prepare by closing the drain hose sea cock and dis-
connecting the hose from the water separator. Con-
duct the test by opening the sea cock while keeping
the hose raised to its fitting on the water separator.
Requirement: There must not be any back flow
while operating the boat throughout its speed range.
If there is, relocate the through-hull fitting.
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11
LOAD WATERLINE
GENSET
MUFFLER
WATER-EXHAUST MIXER LEVEL
SEE OUTLINE DRAWING (PAGE 23)
WATER
SEPARATOR
18 INCH
(457 MM)
MIN.
MUST BE
ABOVE WA-
TERLINE
Notes:
1. All exhaust hose and pipe must slope, without sagging, at least 1/2 inch per foot (42 mm/meter).
2. The operator will not be able to look for water discharge from the hull to tell whether engine/exhaust cooling water is flowing.
However, the genset will shutdown if water stops flowing (Code No. 7). See Troubleshooting in the Operator’s Manual.
12 INCH
(305 MM)
MIN.
SIPHON BREAK NOT REQUIRED WHEN WATER-EXHAUST
MIXER IS AT LEAST 6 INCHES (152 MM) ABOVE LOAD WATER LINE
SEA
COCK
6 INCH
(152 MM)
MAX.
54 INCH
(1.4 METER)
MAX.
FIGURE 2. TYPICAL INSTALLATION ABOVE LOAD WATERLINE—WITH MUFFLER AND WATER SEPARATOR
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