Onan 3.0 AJ User manual

SAFETY PRECAUTIONS
The following symbols in this manual signal poten¬
tially dangerous conditions to the operator or equip¬
ment. Read this manual carefully. Know when these
conditions can exist. Then, take necessary steps to
protect personnel as well as equipment.
WARNING I Onan uses this symbol
throughout this manual to
warn of possible serious personal injury.
This symbol refers to possible
equipment damage.
Fuels, electrical equipment, batteries, exhaust gases
and moving parts present potential hazards that could
result in serious, personal injury Take care in follow¬
ing these recommended procedures.
• Use Extreme Caution Near Gasoline. A constant
potential explosive or fire hazard exists.
Do not fill fuel tank near unit with engine running.
Do not smoke or use open flame near the unit or
the fuel tank.
Be sure all fuel supplies have a positive shutoff
valve.
Fuel lines must be of steel piping, adequately
secured and free of leaks. Use a flexible section of
fuel line between generator set and stationary fuel
line in the vehicle. This flexible section must be
100% NON-METALLIC to prevent electrical
currents from using it as a conductor.
Have a fire extinguisher nearby. Be sure ex¬
tinguisher is properly maintained and be familiar
with its proper use. Extinguishers rated ABC by
the NFPA are appropriate for all applications.
Consult the local fire department for the correct
type of extinguisher for various applications.
• Guard Against Electric Shock
Remove electric power before removing protec¬
tive shields or touching electrical equipment. Use
rubber insulative mats placed on dry wood plat¬
forms over floors that are metal or concrete when
around electrical equipment. Do not wear damp
clothing (particularly wet shoes) or allow skin
surfaces to be damp when handling electrical
equipment.
Jewelry is a good conductor of electricity and
should be removed when working on electrical
equipment.
Always use an appropriately sized, approved
double-throw transfer switch with any standby
generator set. DO NOT PLUG PORTABLE OR
STANDBY SETS DIRECTLY INTO A HOUSE
RECEPTACLE TO PROVIDE EMERGENCY
POWER. It is possible for current to flow from
generator into the utility line. This creates ex¬
treme hazards to anyone working on lines to
restore power.
Use extreme caution when working on electrical
components. High voltages cause injury or death.
Follow all state and local electrical codes. Have all
electrical installations performed by a qualified
licensed electrician.
• Do Not Smoke While Servicing Batteries
Lead acid batteries emit a highly explosive
hydrogen gas that can be ignited by electrical
arcing or by smoking.
• Exhaust Gases Are Toxic
Provide an adequate exhaust system to properly
expel discharged gases. Check exhaust system
regularly for leaks. Ensure that exhaust manifolds
are secure and not warped.
Be sure the unit is well ventilated.
• Keep The Unit And Surrounding Area Clean
Remove all oil deposits. Remove all unnecessary
grease and oil from the unit. Accumulated grease
and oil can cause overheating and subsequent
engine damage and may present a potential fire
hazard.
Do NOT store anything in the generator com¬
partment such as oil or gas cans, oily rags,
chains, wooden blocks, propane tanks, etc. A
fire could result or the generator set operation
(cooling, noise and vibration) may be adversely
affected. Keep the compartment floor clean and
dry.
• Protect Against Moving Parts
Avoid moving parts of the unit. Loose jackets,
shirts or sleeves should not be permitted because
of the danger of becoming caught in moving
parts.
Make sure all nuts and bolts are secure. Keep
power shields and guards in position.
If adjustments must be made while the unit is
running, use extreme caution around hot
manifolds, moving parts, etc.
Do not work on this equipment when mentally or
physically fatigued.

TO THE OWNER
Welcome to the growing family of Onan Power users
. . . We are proud to have you as a customer.
Read this manual carefully and observe all safety
rules within. Operating instructions, adjustments and
periodic maintenance procedures are given so that
you . . , the owner, can keep your unit running like
new and expect many years of dependable service
from it. Remember . . . any machine, regardless of
design or type, will perform only in relation to the
services it receives.
If your generator set needs special attention, ask your
Onan dealer for assistance; the Onan Parts and
Service Organization has been factory-trained to
provide up-to-date know-how for keeping your RV
electric generating set “on the road”, A complete
Parts Catalog is available at nominal cost and may be
ordered under 924-0222.
TABLE OF CONTENTS
General Information. 2
Specifications. 3
Installation Checks. 4
Operation. 6
Adjustments. 9
Engine Troubleshooting Guide. 12
Maintenance. 13
Control Troubleshooting. 17
Remote Accessories. 19
Parts Information. 21
EARNING
TO PREVENT FIRE OR ACCIDENT HAZARD. . .
THIS UNIT MUST BE INSTALLED ACCORDING
TO THE MANUFACTURER’S DETAILED IN¬
STALLATION PROCEDURES OBSERVING ALL
MINIMUM CLEARANCES.
TO AVOID POSSIBLE PERSONAL INJURY OR
EQUIPMENT DAMAGE, ANY INSTALLATION
AND ALL SERVICE MUST BE PERFORMED BY
QUALIFIED PERSONNEL.
1

GENERAL INFORMATION
YOUR MANUAL
This manual contains operation and other informa¬
tion to properly maintain, service, and make ad¬
justments on your AJ generator set. Study and follow
the instructions carefully. A well-planned service and
maintenance program will result in longer unit life and
better performance. Because the most important part
of repair is diagnosis, a troubleshooting chart is
included.
Throughout the manual, engine end of the generator
set is the front. Left and right sides are determined
when facing the engine (front) end.
When contacting your Onan dealer, distributor, orthe
factory about the generator set, always supply the
complete model number and serial number as shown
on the nameplate (see Model Designation following).
This information is necessary to identify your
generator set among the many types manufactured
by Onan.
MODEL DESIGNATION
The following typical model number is broken down
into code segments used by Onan.
3.0 AJ - 1 R 16017 S
—I - r- -r - \ - T~
1 2 3 4 5 6
1. Indicates kilowatt rating.
2. Series identification.
3. Voltage code of the generator, 1 = 120 volts.
4. Method of starting:
R—Remote electric starting.
5. Factory code for designating optional equipment,
if any.
6. Specification letter which advances when the
factory makes production modifications.
FUEL REMOTE CONTROL
PUMP PLUG
GOVERNOR
ADJUSTMENT
VIBRATION ISOLATOR
FUEL SOLENOID
SHUTOFF VALVE
FUEL
INLET
GENERATOR
OIL DRAIN
OIL FILL
VACU'FLO
SCROLL
START-STOP
SWITCH
CARBURETOR-
AIR CLEANER
EXHAUST
OUTLET
CIRCUIT BREAKER
GENERATOR
COOLING AIR
IN
BREAKER
BOX
ENGINE
/
DRIP PAN
TYPICAL AJ RECREATIONAL VEHICLE GENERATOR SET
2

SPECIFICATIONS
This manual contains SI metric equivalents that follow immediately in parentheses
after the U.S. customary units of measure.
GENERAL
Nominal Dimensions of Set
Height. 1 5 . 5 0 in. (394 mm)
Width.12 in. (305 mm)
Length. 23.19 in. (589 mm)
Weight.160 lbs. (73 kg)
ENGINE DETAILS
Manufacturer.
Number of Cylinders.
Displacement (cubic inches)
Cylinder Bore.
Piston Stroke.
Compression Ratio.
Engine Speed.
Engine Design.
Starting System.
GENERATOR DETAILS
Manufacturer. OMAN
Design. Revolving Armature, Two Pole, Inherently Regulated, 3600 RPM
Rating (in watts) 60 Hertz. 3000 Watts (3 kW)
Voltage .120
Current Rating .25 Amperes
Phase.Single
Wire. Two
Power Factor..
Cranking Current. 4 0 Amps
Break-away Current. 225 Amps
CAPACITIES AND REQUIREMENTS
Oil Capacity.
Recommended Battery, Electric Start
Battery Charge Rate—Fixed.
Ventilation Requirements (total).
TUNE-UP SPECIFICATIONS
Spark Plug Gap .025 (0.64 mm)
Breaker Point Gap (cold setting).022 (0.56 mm)
Ignition Timing Reference (cold setting).22° BTC
Valve Tappet Adjustment (engine cold)
Intake.011 (0.28 mm)
Exhaust.018 (0.46 mm)
.2 qts. (1.89 litres)
12 Volt, 92 Amp/hr (331.20 kC)
. 1-2 Amps
.50 sq. in. (323 cm^)
. OMAN
.One
. 14.9 (244.16 cm3)
.2-3/4 in. (69.85 mm)
.2-1/2 in. (63.50 mm)
.6.25:1
.3600 RPM
Four Cycle, Air Cooled, L Head
... Exciter Cranking Generator
3

INSTALLATION CHECKS
INSTALLATION
Nearly all Onan electric generating sets are installed
by the motor home manufacturer. Although the
manufacturer must follow safety codes when install¬
ing, certain installation problems could ariseafterthe
unit is installed and subjected to vibration. There are a
few areas that you as the operatorshould be concern¬
ed with. If in doubt aboutany aspect ofyourgenerator
set’s operation or safety, contact your nearest
authorized Onan Service Center. A daily inspection of
your installation should include the following;
• Exhaust
• Fuel System
• Electrical
• Ventilation
EXHAUST
Check for leaks around manifolds, gaskets and welds.
Make sure exhaust lines are not heating surrounding
areas excessively. If so, have corrected immediately.
Remember EXHAUST GASES CONTAIN DEADLY
CARBON MONOXIDE. Be sure all holes to the inside
of RV from set compartment are sealed to prevent
poisonous exhaust gases from entering vehicles.
FUEL SYSTEM
With set running, check for leaks. Raw fuel will cause
fumes which could EXPLODE. Check around car¬
buretor and fuel pump inlets. Make sure fuel lines are
not rubbing against anything which could cause
breakage.
Inlet hose connection to fuel filter requires a clamp.
ELECTRICAL
AC Output
Two AC leads. Ml (hot) and M2 (ground), terminate in
generator junction box. These wires should be con¬
nected to distribution box with multistrand wire
enclosed in a flexible conduit. Check all wires (to and
from the generator set) for fraying and loose connec¬
tions. For information on load connections refer to
OPERATION section following.
Battery Connections
Battery positive (+) connection connects to start
solenoid. Battery negative connects to location on
rear of generator. Check terminals on set and battery
for clean and tight connections.
4

Onan recommends using a separate battery for operation of the
generator set in addition to the regular vehicle starting battery.
Refer to individual installation guide or T-012 for additional
information on battery sharing.
WARNING^ discharged cooling air for com¬
partment heating since it could contain
poisonous exhaust gases.
Grounding: Generator must be effectively bonded to
recreational vehicle chassis.
For additional information on installation contact
your ONAN Service Representative or request In¬
stallation Guide #924-0611.
Vehicle chassis (frame) ground and the battery and generator set
ground should all be electrically connected to be at 0 ground
potential. All Onan units are designed for negative ground
apollcation.
WARNING
ANSI 198.1 AND
recreational vehicles
I Insulation must not reduce the minimum
I clearances as specified In Figure 1 to meet
CSA #946 temperature rise requirements for
Do not terminate poisonous carbon monox¬
ide exhaust gas under vehicle. Direct exhaust
gases away from window and door openings. Keep all openings
above or to the rear of exhaust pipes closed when generator set Is
operating.
WARNING \
WARNING
DO NOT DISCONNECT BATTERY CABLES
FROM BATTERY WHILE GENERATOR SET
IS CRANKING OR RUNNING; SPARKS MAY CAUSE AN EXPLO¬
SION.
WARNING
Mount the battery In a separate compartment
from the set or any spark-producing device to
prevent fire or explosion.
WARNING I
being charged.
Do not smoke while servicing batteries. Lead
acid batteries give off explosive gases while
VENTILATION
The biggest enemy of electric generating sets in¬
stalled in motor homes is excessive heat. Make sure
the set's air inlet and outlet are not plugged with dust,
dirt, bugs, leaves or anything that could restrict
cooling air.
IMPORTANT: Certain states (particularly California) have state
ordinances pertaining to the type and usage of exhaust
muffler/spark arresters on internal combustion engines or engine
driven equipment when used In a recreational vehicle such as
electric generating sets. Be sure your installation meets all Federal,
State and local codes pertaining to your unit. Failure to provide and
maintain a spark arrester may be in violation of the law.
WARNING i
ENGINE EXHAUST GAS (CARBON MONOXIDE) IS DEADLY!
Carbon monoxide Is an odorless, colorless gas formed by Incomplete
combustion of hydrocarbon fuels. Carbon monoxide is a dangerous gas that
can cause unconsciousness and is potentially lethal. Some of the symptoms or
signs of carbon monoxide inhalation are:
• Dizziness • Vomiting
• Intense Headache • Muscular Twitching
• Weakness and Sleepiness • Throbbing in Temples
if you experience any of the above symptoms, get out into fresh air
immediately.
The best protection against carbon monoxide inhalation is a regular inspection
of the complete exhaust system. If you notice a change in the sound or
appearance of exhaust system, shut the unit down immediately and have it
inspected and repaired at once by a competent mechanic.
5

OPERATION
GENERAL
inspection: Inspect the engine visually before star¬
ting. Check for loose or missing partsorany shipping
damage. The unit may be tilted during operation to
any maximum angle not exceeding vehicle operation
limitations.
Rust inhibitor oil has been placed In the engine combustion
chamber at the factory and may foul the spark plug. If the plug
should foul, remove it and clean thoroughly. Then dry and replace
in engine.
RECOMMENDED FUEL
Use ciean, fresh, unleaded or regular grade gasoline.
Do not use highly leaded premium fuels. Using
unleaded gasoline results in reduced valve and
carbon cleanout maintenance.
If the use of unleaded gasoline is desired, use regular
gasoline for the first 25 hours to allow the rings to seat
well for best performance. Then use unleaded gas¬
oline thereafter.
If regular gasoline is used continually, carbon and
lead deposits must be removed from the cylinder
heads as required because of engine power loss.
Unleaded gasoline may be used safely after lead
deposits have been removed.
Leakage of gasoline in or around the com¬
partment is a definite hazard. The ventilation
system should provide a constant flow of air to expel any
accumulation of fuel vapor while the vehicle is in transit. Com¬
partments must be vapor tight to the interior to keep fumes from
within the vehicle.
OIL
Check oil level daily (see Figure 2). Be sure unit is
level when checking oil. Add oil to top of fill hole if
required. See MAINTENANCE section of this manual
for type of oil, oil viscosity and crankcase capacity.
Do NOT check oil while the generator set is
operating. Hot oil could cause bums by
blowing out of oil fill tube due to crankcase pressure.
STARTING
Push the start-stop switch to the start position.
Release the switch when engine starts. If engine fails
to start, inhibitor oil used at the factory may have
fouled the spark plugs. Remove the plugs, clean in a
suitable solvent, dry thoroughly and re-install. Heavy
exhaust smoke when the engine is first started is
normal and caused by the inhibitor oil.
OIL DRAIN
FIGURE 2. OIL LEVEL
STOPPING
Push the start-stop switch to the stop position and
hold until unit stops completely.
Automatic Choke
An electric choke provides proper choking for star¬
ting and running the generator set.
BREAK-IN PROCEDURE
Controlled break-in with the proper oil and a con¬
scientiously applied maintenance program will help
to assure satisfactory service from yourOnan electric
generating set. Break-in as follows:
1. One half hourat1/2load (with oneairconditioner
running).
2. One half hour at 3/4 load (with one air con¬
ditioner) and approximately 500 watts additional
load.
3. Change crankcase oil after the first 25 hours of
operation.
APPLYING LOAD
If practical, allow set to warm up before connecting a
heavy load. Continuous generator overloading may
cause high operating temperatures that can damage
the windings. Keep the load within nameplate rating.
BATTERY CHARGING
The battery charge rate is controlled by a fixed value
resistor that allows a trickle charge rate of 1 - 2 amps
under all conditions.
6

SET EXERCISING
Establish an exercise program if unit is not used for
long periods of time. Start and run unit, with a full load
connected if possible, for at least 30 minutes every
week. This exercise program will:
• Lubricate internal engine parts.
• Assure proper starting when set is needed.
• Remove moisture.
• Keep carburetor filled with fuel.
• Bring engine up to operating temperature.
• Recharge battery.
ELECTRICAL OUTPUT
The generator set’s wiring provides for 120 volts, with
the total electrical load not to exceed 25 amperes.
install any outlets between generator
^distribution panel.
120 VOLT. 2 WIRE
UNGROUNDED LOAD WIRE
30 AMP
^ BLACK
120 V (FULL NAMEPLATE RATING)
y WHITE
GROUNDED LOAD WIRE
IM1
GENERATOR LEADS
M2
FIGURE 3. SINGLE-PHASE, “1R” VOLTAGE CODE
GENERATOR CONNECTIONS
POWER REQUIREMENTS FOR APPLIANCES
Appliance or
Tool
Approximate
Running Wattage*
Refrigerator. 600-1000
Electric broom . 200-500
Coffee percolator. 550-700
Electric frying pan. 1000-1350
Hair dryer. 350-500
Electric stove (per element). 350-1000
Electric iron. 500-1200
Radio. 50-200
Electric water heater. 1000-1500
Space heater. 1000-1500
Electric blanket. 50-200
Television. 200-600
Electric drill. 250-750
Battery charger. Up to 800
Electric water pump . 500-600
Air Conditioner. 1400-2200
Converter. 300-350
Microwave oven.700-1500
' - Starting wattages for motors can be three to four
times more than the approximate running wattages.
HIGH OPERATING TEMPERATURES
1. See thatnothingobstructs air flow to and from the
set.
2. Keep cooling fins clean. Air housing should be
properly installed and undamaged.
3. Keep ignition timing properly adjusted.
LOW OPERATING TEMPERATURES
1. Use co; • :t SAE oil for temperature conditions.
Change oil only when engine is warm. If an
unexpected temperature drop causes an
emergency, move vehicle to a warm location.
2. Use fresh gasoline. Protect against moisture
condensation. Below 0° F (-18° C), adjust car¬
buretor main jet for a slightly richerfuel mixture.
3. Keep ignition system clean, properly adjusted
and batteries in a well charged condition.
4. Partially restrict cool airflow, but use care to avoid
overheating.
EXTREMELY DUSTY OR DIRTY
1. Keep unit clean. Keep cooling surfaces clean.
2. Service air cleaner as frequently as necessary.
3. Change crankcase oil every 50 operating hours.
4. Keep oil and gasoline in dust-tight containers.
5. Keep governor linkage clean.
6. Clean generator brushes, slip rings, and com¬
mutator: do not remove normal dark brown film.
Do not polish.
HIGH ALTITUDE OPERATION
For operation at altitudes of 2500 feet (775 m) above
sea level, close carburetor main jet adjustment slight¬
ly to maintain proper air-to-fuel ratio (refer to the
ADJUSTMENTS section). Maximum power will be
reduced approximately four percent for each 1000
feet (310 m) above sea level after the first 1000 feet.
Do not use discharged air from blower scroll
for compartment heating. Poisonous gas
fumes may be present.
OUT-OF-SERVICE PROTECTION
Protect a generator set that will be out of service for
more than 30 days from damage caused by rust or
corrosion. Use the following procedure to properly
protect the set.
1. Run the generator set with at least a 50 percent
load until thoroughly warm (usually about 1
hour).
2. Turn off fuel supply and allow the engine to run
out of fuel. Also operate the choke manually as
the engine stops to help drain the carburetor
completely.
warning!
7

3. Drain the oil from oil base while engine is still
warm. Replace the oil filter if so equipped.
Replace drain plug and refill. Attach a warning tag
stating type and viscosity of oil used.
4. Remove spark plug. Spray 1 ounce of rust in¬
hibitor oil (or SAE #10) into the cylinder. (Spray
cans work well for this application.) Turn engine
over by hand at least 2 complete revolutions.
Replace the spark plug.
5. Replace the air cleaner at least on an annual
basis.
6. Plug the exhaust outlet to prevent entrance of
moisture, dirt, bugs, etc.
7. Clean and oil all exposed engine parts including
carburetor and governor linkage.
8. Wipe generator brushes, slip rings, housing, etc.
Do not apply any lubricant or preservative.
9. Remove the battery and store in a cool dry place.
Coat the battery terminals and cable connections
with vasoline or grease to prevent any corrosion.
Recharge the battery at least monthly or maintain
with a trickle type battery charger.
10. P r ovide a suitable cover if the unit is exposed to
the elements.
RETURNING THE UNIT TO SERVICE
1. R e m o v e the cover and all protective wrapping.
Wipe the oil film off all exposed engine parts.
Remove the plug from the exhaust outlet.
2. Visually inspect the unit for any damage. Check to
be sure the carburetor and governor linkage are
free. Remove the generator end bell band and
check to be sure the brushes work freely in their
holders.
3. Check the tag to ensure oil of the proper brand
and grade has been installed. Check the oil level.
4. Install the battery (be sure battery is fully charg¬
ed), observing proper polarity. Ground is
negative.
5. Remove spark plugs, clean and gap. Turn the
engine over by hand several times. Reinstall spark
plugs.
6. Remove all load and start the generator set at the
unit. Initial start may be slow due to oil or rust
inhibitor in the cylinders. Excessive smoke and
rough operation will occur until the oil or rust
inhibitor is burned off.
7. Apply a 50 percent load after the set runs smooth.
Allow the generator set to warm up (1 hour) with
the load connected. Check speed and voltage.
8. Unit is now ready for service.
GENERATOR MAINTENANCE
The generator normally needs little care other than a
periodic check of the brushes, commutator and
collector rings. If a major repair job on the generator
should become necessary, have the equipment
checked by a competent electrician who is thorough¬
ly familiar with the operation of electric generator
equipment.
8