Onan MDJF Series Instruction Manual

OPERATORS
AND
ANUAL
FOR
Onan
ELECTRIC GENERATING SETS
MDJF
SEkiES
t
968-0345
6Abt3

TABLE OF CONTENTS
TITLEPAGE
GeneralInformation 3
Specifications 4
Dimensions and Clearances 5
AssemblyTorques and SpecialTools 7
Installation 8
Operation . 17
Adjustments 21
GeneralMaintenance 24
RoutineCheckChart 26
MaintenanceSchedule . . 27
TroubleshootingGuide 28
PartsCatalog 29
PERFORMANCE
CERTIFIED
We certify thatwhenproperlyinstalledand operated
thisOnanelectricplant will deliverthe full powerandthe
voltageandfrequencyregulationpromisedbyits nameplate
andpublishedspecifications.Thisplanthas undergone several
hours ofrunning-inandtesting under realisticloadconditions,
in accordance with procedures certified byanindependent
testinglaboratory.
ONAN 140073RDAVENUE
N.E.• MINNEAPOLIS,MINNESOTA55432
*OIVISIOH Of ONAN CORPOI'llON
IMPORTANT! RETURN WARRANTY CARD ATTACHED TO UNIT.

INTRODUCTION
THISOPERATOR'S MANUAL CONTAINS INFORMATION PERTAINING
TOTHEINSTALLATION,OPERATION,ANDMAINTENANCEOFYOUR
ONAN UNIT. A PARTSCATALOGISALSOINCLUDEDINTHIS
MANUAL.
WESUGGESTTHATTHIS MANUAL ANDTHE WIRING DIAGRAM WHICH
ACCOMPANIES EVERY ONAN UNIT BERETAINEDAND REFERRED
TO WHEN MAKING EQUIPMENTADJUSTMENTSORORDERINGPARTS.
ADDITIONALCOPIESAREAVAILABLEFORA NOMINAL CHARGE
FROMYOUR ONAN DISTRIBUTOR.
WHEN ORDERINGPARTSREMEMBERTOINCLUDETHE ONAN
MODEL,SPECIFICATION LETTER, ANDSERIALNUMBERLOCATED
ONTHENAMEPLATEOFYOUR ONAN UNIT. THISISESSENTIALTO
ENSURE THECORRECTPARTISSHIPPEDTOYOU.
FOR MAJORREPAIR SERVICE, CONTACTYOUR ONAN AUTHORIZED
DISTRIBUTOR.

GENERAL INFORMATION
When theinsttuctionsinthismanualrefertoa specific
modelofgeneratingset,identifythemodelbyreferring
tothe MODEL AND SPECIFICATION NO.asshownon
the Onan nameplate. Electrical characteristicsareshown
onthelowerportionofthesetnameplate.
How to Interpret MODEL and SPEC NO.
15 OMDJ F - 4R/ 96 D
1 3
4
1.Factory code forgeneralidentification.
2. Specific Type:
E - ELECTRIC. Electric startingatthesetonly.
R - REMOTE. Electric starting.Forpermanentinstalla-
tion,canbeconnectedtooptionalaccessoryequipment
forremoteorautomaticcontrolofstartingandstopping.
3. Factory code foroptionalequipment.
4.Specification(Spec)letter(advanceswhenfactory
makesproductionmodifications).
CAUTION
'Onan uses this symbol throughout the text
to warn ol possible equipment damage.
WARNING |^"ssym^'s used to warn ol any possi-
H^HHMBBi^J&/e personal injury.
MANUFACTURER'S WARRANTY
Onanwarrants.Inihe nrigmal iiAt-r. thaitar.bproductofitnma mi fact u
is frrr frnm drfwlft in. motrriol onH fnrlory workmanshipifproperlyin*
siollcil. servicedandoperatedundernormalconditionsaccordingto Onan's
inplrnrlinno.
Onan will, underthis worrnnty. repairnrreplace,asOnanmayelect,any
pan which onexamination nhall diocloaeto Onan's fintisfaction lohove
hern defeciiveinmaterialandworkmanship:providedlhatsuchpart .ihall
hereturnedto Onan's factoryoroneofitsAuthorizedServiceSta linns,
ironsporluiion charges prepaid,not hiler thanone f I) yearaflertheproduci
if first placedin wrvic*. Suchdefectivepart will herepairedorreplaced
freeofcharpe, including lahor(in accordance wilh rates approvedhyOnon)
during ihestatedone(1)yearcoverageunder thin warranly.
THIS WARRANTY AM) ON.AN'S OII LIGATION TMKRF.l'NDK.H IS
IN l.l KL.' OKALL VIARK.ANTIK.S. KX I'H KSSK.I) OK I.MPUKO. IN-
<XUr>l.N(; WITHOUT LIMITATION.THK IMIMJKI) W.ARRANTIKS
OK MKRCIIANTAIIIUTY AND K ITN KSS KOHA PARTICULAR
I'l HI'O.SK. ANOAM. OTIIKH OIII.I<;ATIONS OR I.1ABILITIKS.
I.NCI.I IHN<; LIAHILITY KOK INCIDKNTAI. AND CONSKQt'KN-
TIM. DAM ACK.
No ]MTMin i>aulhoriiedlopi\eanyotherwarrantyorloa*<iumeany olhei
lialiililt on Onan's (..-half unh-** made ora KM u med' in wrilinp hyan fKhr.
of * Inuu. amino jiernon ii> uulhorizediopiveanvwarranlvoi
liuhililies ..niheSeller's l.ehalf unle« made'ora^nmedin writinp hy
>urh Sell. r.
ONAN

SPECIFICATIONS
Nominal dimensionsofgeneratingset(inches):
Height 2611/16
Width 205/16
Length '.513/8:'
Weight (approx.lb.)'. :.'..".....865
Numbercylinder(vertical in-line) 4
Displacement(cubicinch)140
Cylinder bore< , 31/2
Pistonstroke3 5/8
BHP at1800rpm: 33.3
RPM (for 60 hertz) 1800
RPM (for50hertz)1500
Compressionratio19:1
Battery voltage(ACset,exceptdualpurpose)*12
Batery size (ACset,exceptdualpurpose)
SAE group IH-two in series • Yes
Amp - hr,SAE20- hr(nominal)120
Battery charge rate amperes (normal)- AC sets 2 to5
*Oil capacityinU.S. quarts - Refill : .•6
Cooling water flow (gallonsperminute). ' 6
Generatorcoolingair (CFM at1800rpm)136
Combustion air (CFM at1800rpm): ^ '2
Total cu.ft.permin.ofairrequired208
Diesel fuel lift (maximumfeet).'6 •"
Maximum recommendedpower take-off from front pulleyatanyload2 hp
Power take-off limit atratedload'. 1 hp.
Injection pump (Am. Boschtype)PSU
Output isratedat unity powerfactorload 1-phase
Output isratedat0.8powerfactor 3-phase
Rating (outputinwatts)
AC, 50hertzset.,12,000
AC, 60hertzset, 15,M0
AC voltageregulation in t %
: ; 3
AC frequencyregulationin % .•5
Revolving field type generator , Yes
120/240- volt single phase modelreconnectibleYes
Statictypeexciter(Magneciter): Yes
* - Plus1/2quartfornew filter.
• . 24and32voltbatteriesoncertainmodifications.
NOTE: Hertzisa unit offrequencyequaltoonecycleper second.

DIMENSIONS AND CLEARANCES
Allclearancesgiven at roomtemperature of 70°F.
Alldimensions in inchesunlessotherwisespecified.
MinimumMaximum
CAMSHAFT
Bearing JournalDiameter,Front2.25002.2505
Bearing Journal Diameter, Rear 1.1875 1.1880
Bearing Clearance Limit 0012.0037'
End Play,Camshaft(inback position) 007.039
Cam Tappet Hole Diameter8755.8765
Cam TappetDiameter8730.8725
CONNECTINGRODS
Large BearingDiameter (I.D.) ' 2.06152.0630
Small BushingDiameter (I.D.) . . . 0.99030.9906
Clearance,LargeBearingtoCrankshaft' 001.0033
CYLINDER
Cylinder Bore3-1/2
Cylinder Diameter Limits 3.49953.5005
CRANKSHAFT
Main BearingJournalDiameter2.24272.2435
Crankshaft Main BearingClearance (Original Equipment)0030.0043
Connecting RodJournalDiameter2.05972.0605
End Play,Crankshaft010.015
PISTON(Measure 90°toPin)
Piston Clearanceto Cylinder Wall belowOil Ring Groove0055.0075
Piston Pin Hole Diameter99005.99025
Ring Groove Width, Top097.098
Ring Groove Width, 2nd. .0965.0975
Ring Groove Width, 3rd0965.0975
Ring Groove Width, 4th1895.1880
PISTON PIN
Length 3.003 2.988
Diameter 9899.9901
Piston ClearanceThumbPushFit
Connecting RodBushingClearance0002.0007
PISTON RINGS
Ring Type
Top Compression
2nd Compression
3rd OilScraper& Compression
RingWidth
Top f 0925.0935
2nd 0925.0935
3vd *":::09251 .0935

Minimum Maximum
STARTING MOTOR
Rotation ". . . . Counterclockwise
Pinion Clearanceto Pinion Stop(SolenoidPlungerBottomed).070.120
Pinion RestPosition — Distance from Pinion Housing Mounting Face
to OuterEdgeof Pinion 1-9/32 1-15/32
Armature EndPlay.005.030
TestSpecifications
No Loadv.;10volts- 80 amps
5000 rpm Min.
Stall Torque4volts- 420 amps
7.8lbs. ft. Min.
Brush SpringTension32-40 ounces
with new brushes
VALVE, INTAKE (Hardened Chrome Alloy)
StemDiameter.3405.3410
ClearanceinGuide'. . . . . . .0015.0030
Valve Face Seat Angle . . . 426
Valve Clearance.017
VALVE, EXHAUST (Hardened Chrome Alloy)
StemDiameter3405.3415
ClearanceinGuide". . . .0030.0050
Valve Face Seat Angle 45°
Valve Clearance.017

ASSEMBLY TORQUES AND SPECIAL TOOLS
TORQUE SPECIFICATIONS FT.-LB.
Center Main Bolt 97-102
Connecting Rod Bolt 27-29
Cover-RockerBox8-10
Cylinder Head Bolt 44-46
Exhaust Manifold Nuts13-15•
Flywheel Mounting Screw65-70
Flywheel HubNut17-21
Fuel Pump Mounting Screws. 15-20
Gear Case Cover. 18-20
Glow Plug10-15
Injection Nozzle Mounting Screws20-21
Injection Pump Mounting Screws15-16
Intake Manifold 13-15
Oil Base Mounting Screws45-50
Oil Filter Hand Tight + 1/4to1/2 Turn
Oil Pump Mounting Screws15-20
RearBearingPlate4045
Rocker Arm Nut4-10*
Rocker Arm Stud. ...35-40
Thru-Rotor-Stud Nut55-60
* - Thistorqueis friction betweenthe threads only and
locks thenutsinplace.Therockerarmnutsarefor
adjusting valvelash.
CAUTION
Tighten nuts evenly to avoid manilold
damage.
Assembly torques assure propertightness without dangerof
stripping threads.Ifa torquewrenchisnotavailable,
estimatethe degree oftightness.Use reasonable forceand
awrenchofnormallength.
SpecialPlaceBoltsdonotrequirelockwashersor gaskets.
Never attempttousea lockwasher with these bolts,it
will defecttheirpurpose.Checkallstuds,nutsandscrews
often. Tightenasneeded.
SPECIAL TOOLSANDEQUIPMENT
These toolsareavailable from Onantoaidserviceand
repair work.
CrankshaftGear Pulling Ring 420-0275
Diesel CompressionTester420-0283
Diesel NozzleTester420-0184
Diesel PintleNozzleCleaning Tool Set
(Includes injection nozzlecentering tool) . . . 420-0208
Driver, FrontCamshaftBearing420-0252
Driver, RearCamshaftBearing420-0251
Driver, CenterCamshaftBearing420-0254
Driver, Main BearingFrontandRear420-0269
Driver, Valve Seat 420-0270
Oil SealGuideand Driver RearFront420-0281
Ridge Reamer420-0260
ReplacementBladefor420-0260420-0261
Valve Seat Remover420-0272
ReplacementBladesfor420-0272 4 20-0274

INSTALLATION
GENERAL
Proper installation is very important. Consider thefollowing
points: adequate generator coolingair; discharge ofcircu-
lated air; adequate fresh inductionair; adequate engine
cooling water; discharge of circulated water; discharge of
exhaust gases; electrical connections; fuel connection;
sturdy andflatfloor;and accessible for operation and
service. Use this manual asa guide to help withthe
installation; refer toTypical Installation, Figures 2 and3.
For more complete instructions, request Onan Technical
BulletinT-021.
Each installation must be considered individuallyand exe-
cuted in compliance withall regulations whichmay affect
the installation. The advice and guidance contained inthe
booklet entitled Fire Protection Standard (orMotor Cralt:
(NFPANo.302) offered bythe National Fire Protection
Association International, Boston 10, Massachusetts, will
behelpfultothe installer of equipment in vessels.
CAPSCREW
LOCKWASHER
FLATWASHER
SNUBBER
"GENERATOROR
OILBASEMOUNT-
INGFOOT
CUSHION
MOUNTINGSPACER
BUSHING
'-DRIPPAN
FIGUREI.MOUNTINGCUSHION
LOCATION
Select a location fortheunit, preferably near the vessels
main keel, whichisdry, properly ventilated, above low
lying vapors and splash fromthebilge. Provide accessibility
for minor servicing operations, draining ofthe crankcase,
lubricatingoilandthecooling system.
MOUNTING
Thefloor should beflatand give support directly under the
set (Figure 1) mounting points. Theunit will rock onits
mounts.
A 2-1/2inch clearance around theunitis required to permit
rockingonits mounts without restraint. Use adequately
flexible exhaust line,fuelline, batteiy cables, and elec-
trical wires.
WATERLINE EXHAUSTHIGHWATERTEMP-
ERATURECUTOFFSWITCH
SUPPORT
MUFFLER
RUBBER
EXHAUST
HOSE
.^LOAD
<LWATER
LINE
VENTILATED
BATTERYBOX
FIGURE2.TYPICALINSTALLATION

Recommendedfluahtypethru-hull
fittingandwaterfilter.
TOGENERATORSET
SEACOCK
STRAINER
v— FLUSHTHRU-HULL
FITTING
WARNING:Donotusescooptypewaterinletfittings
ongeneratorsetsusingAqualiftmufflersystems
CAUTION Install Siphon Break Kit #155-0950 il
exhaust injection elbow is below load
wa'er line. Locate the Siphon Break at least 12inches
above load water line and in a vertical position. Remote
mounting the siphon break is permissible within a 5 loot
radius ol water injection exhaust elbow. Vertical position
and height ol valve must be maintained.
SIPHONBREAK•
(Seedetail)
-HANSERSTRAPS
Sf|VACUUMRELIEFVALVE
ADAPTER
/""ELBOW(2)
'RUBBERHOSE
WATEROUTLET
EXHAUSTWATER
INJECTIONELBOW
EXHAUSTOUTLET
TYPICAL ABOVE WATER LINE
INSTALLATION
NOTE:
Makeprovisionforpassageofairbeneath
mufflertopreventcondensation..
TYPICAL
BELOW WATER LINE
INSTALLATION
FIGURE 3. TYPICAL INSTALLATION
Installtwo hold-down clamps tothedrippan(frontand rear
or both sides). Secure the clamps tothe mounting base. For
maximum noise reduction on Onan MDJF units, installthe
Onan "Sound Shield" whichisan insulated fiberglass
enclosure which completely surrounds'the generating set
(Figure 2). Openings are provided for connection toallex-
ternal lines and wires. Internal air ducts reduce air borne
noise toa minimum. Contact your localONAN dealer for
noise reduction methods andthe special kits whichare
available.
shut-off valve atthe tank. When thefuel tank is shared with
another engine, usea separate fuellineand return linefor
each to avoid starving the plant. (Figure 4)..
If fuel lift must exceed 6-feet, installanauxiliary electric
fuel pump atthefuel supply.
FUEL TANK
If a separate fuel tank is used, installthe tank sothe bottom
is less than 6^feet below thefuel pump. The tank top must
be below fuel pump levelto prevent siphoning. Installa
FUEL CONNECTION
Connect the fuel line to the fuel pump inlet. Pump is threaded
7/16-24 NPTF (American Standard Internal Tapered Pipe
Thread). Important: Always use llexible tubing between en-
gine and the luel supply.