Onan Ensign 4500 User manual

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MCE
Ensign Series 4500/6500
Printed in U.S.A. 927-0600
8-93

Safetv Precautions
Before operating the generator set, read the Operator's
Manualandbecomefamiliarwithitandyour
unit. Safe andeffl-
cient operation can be achieved only if the unit is properly
operated
and maintained. Many accidentsarecaused byfail-
ure to follow fundamental mles and precautions.
Thruugkout
this manualyou will noticesymbolswhichalert you
to potenliaHy dangerousconditions to theoperator,service per-
sonnel, or the equipment itself.
. l' This symbd warns of immediate haz-
ards which wiil result in severe personal fnjury or
death,
EWARtMG, This symbol refersto a hazardorunsafe
practicewhichcanresuitinseverepersonalinjury
or
death.
l%~cAu-tror\l Thls symbol refers to a hazard or unsafe
practh? whichcanresultinpersonalInjuv or prod-
oct
or property damage.
FUEL, ENGINE OIL, AND FUMES ARE FLAMMABLE AND
TOXIC.
Fire, explosion,andpersonalinjurycan resultfrom im-
proper practices.
Benzene and lead, found
in some gasoline, have been
identified
by some state and federal agencies as causing
cancer
Or reproductive toxicity. When checking,draining
or adding gasoline, take care not
to ingest, breathe the
fumchs, or contact gasoline.
Used engine oils have been identified by some state or
federal agencies as causingcancgr or reproductive toxic-
ity.
When checkingorchangingengine oil, take care not to
ingest, breathe the fumes, or contactused oil.
Do not fill fueltankswiththeengine running. Do not smoke
around
the generator set area. Wipe up any oil or gas
spills.
Do not leave oily rags in enginecompartment or on
the generator set. Keep this and surrounding area clean.
InsprxAfuel
system beforeeachoperationand periodically
while running.
Equip the engine fuel supply with a positive fuel shutoff.
Always disconnect the battery ground (-) lead first and re-
conmct it last. Make sure you connect the batlery cor-
rectly.
A direct short across the battery terminals can
CPUSCI anexplosion. Do not smokewhile servicingbatter-
ies. Hydrogen gasgiven off during charging is very explo-
sive.
Keep a fire extinguisher available in or near the engine
cornpa-tment and
in other areas throughout tke vessel.
Use the correct
ex?inguisher for the area. For most types
of fires, an extinguisherrated AB6 by the NFPA is avail-
able ancl suitablefor use on all types of firesexceptalco-
hol.
EXHAUST GASES ARE DEADLY
e Provide adequateventilation. Equipthebilge with a power
exhauster.
Be surepropuhion and generatorset engineexhaust zys-
ternsare free of leaks. Perform thorough, pcriodrc in:pec-
tions
of the exhaust system and repair leaksimmedistsly.
E:<haust
gases are deadly.
Never sleep in the vessel with the generator set running
unless the vessel is equipped with an operating carbon
monoxide detector.
,
HOT COOLANT CAN CAUSE SEVERE PERSONAL
INJURY
Hot coolant is under pressure. Do not loossn the coolant
pressure
cap while the engine is hot. Let the engina coal
before opening the pressure cap.
MOVING PARTS CAN CAUSESEVERE PERSONAL
INJURY OR DEATH
Do not remove any belt guardsor covers with the genm-
tor set
running.
Keep hands and loose clothing awayfrom moving parts.
Do not wearjewelry while servicing any part of the genera-
tor set.
Never step
on thegsneratorset(aswhenentering or leav-
ing the enginecompartment). It canstressand break unit
components, possible resulting in dangerous operating
conditions.
. from leaking fud, leaking exhaust fumes,
etc.
Before performing any maintenanceon thegerierator cet,
disconnect its batteriesto prevent accidentalstarting. do
not disconnector connectbattery cables if fuel vapors are
present. Ventilatethe generator set compartmentor bilge
thoroughly with the power exhauster.
ELECTRICAL SHOCK WILL CAUSE SEVERE
PERSONAL INJURY OR BEATH
Do not make adjustments in the controlpanel or on engine
with
unit running. High voltages are present. Work that
must be done while unit is running should be doneonly by
qualified service personnel standing on dry surfaces to re-
duce shock hazard.
.
DO NOT CONNECT THE GEldEFWTOR SET TO THE
PUBLIC UTILllY OR TO ANY OTHER ELECTRICAL
POWER SYSTEM. Etectrocuti n or damage to property
can occur
at a sita remote from the boat where line cor
equipmentrepairs are being made if the st is connected
tothe
power system. An approved bander switch mu3 be
used if more than one power source iz to be made avail-
able to servicethe boat.
Do not workonthisequiprnentwhen ~enfa:llyor physically
fatigued,
or after consuming any alcohol or drug that
makes
the operation of equipmmt unsafe.
bit 8
Copy and post these suggestloris in potential hazard areas of the vessel.

Table of Contents
SECTION TITLE PAGE
1 .
2 .
3 .
4 .
5 .
6 .
7 .
8 .
9 .
10 .
SAFETY PRECAUTIONS ............................... Inside Front Cover
INTRODUCTION ................................................... 1-1
General ......................................................... 1-1
Installation Codes and Safety Recommendations ........................ 1-1
Generator Details ................................................. 2-1
Engine Details
................................................... 2-1
Location ........................................................ 3-1
Mounting
........................................................ 3-1
General
......................................................... 4-1
Requirements .................................................... 4-1
Coast Guard and NFPA Requirements ................................ 4-1
General ......................................................... 5-1
Heat Exchanger Cooling ............................................ 5-1
SPECIFICATIONS .................................................. 2-1
LOCATIONAND MOUNTING ......................................... 3-1
VENTILATION ..................................................... 4-1
COOLING SYSTEM ................................................. 5-1
SeaWater Cooling
................................................ 5.3
Combined Cooling Systems ......................................... 5.3
EXHAUST SYSTEM ................................................ 6.1
General
......................................................... 6. 1
Below Load Waterline Installation
.................................... 6-3
Above Load Waterline Installation .................................... 6-4
FUELSYSTEM .................................................... 7.1
General ......................................................... 7-1
Installation
...................................................... 7.1
Fuelianks ...................................................... 7.2
Fuel tines
........................................................ 7.3
SiphonProtection
................................................. 7-3
FuelSystemTest ................................................. 7-3
ELECTRICALSYSTEM .............................................. 8-1
General
......................................................... 8-1
Load Connections .................................................. 8-1
Remote Starting Controls ........................................... 8-4
Batteries ........................................................ 8-4
Installation
Checks ................................................ 9.1
Initial Starting and Checks .......................................... 9-1
FINAL INSTALLATIONCHECKS ...................................... 9.1
DC WIRING DIAGRAM ............................................. 10-1
i

Section 1. Introduction
GENERAL
Eachmarinegeneratorset mustbeinstalledproperly if it
is to operate reliably, quietly, and most important -
safely. Therefore, readthisentire manual beforestarting
the installation. The manual should be used only as a
guide as each installation must be considered on an
individualbasis. Foroperationand maintenanceproce-
dures, refer to the MCE Operator‘s Manual 927-0124
which accompanieseach unit
Proper installation is very important Requirements to
consider should include:
Adequate cooling air
a Adequate combustionair
a Discharge of exhaust gases
a Discharge of circulatedair
Electricalconnectionsand bonding
Fuelconnections
Seawater connections
a Accessibility for operationand servicing
a Level mountingsurface
a Adequate support under mounting points
a Noiselevels
INSTALLATION CODESAND SAFETY
RECOMMENDATIONS
The insthation must follow recommendations of the
American Boat and Yacht Council (ABYC) and the
National FireProtectionAssociation (NFPA).
The installer should be familiar with and follow the
appropriate guidance found in the following
publications:
ABYC
“Safety Standards for Small Craft”from:
ABYC
15 East 26th St
NewYork, NY 10010
NFPA302 “Fire Protection Standard for Motor Craif”from:
NFPA
470 AtlanticAvenue
Boston, MA
02210
USCG 33CFR183from:
U.S. GovernmentPrintingOffice
Washington, D.C. 20404
~AWARNING 1
INCORRECT SERVICE OR REPLACEMENTOF PARTSCANRESULT IN SEVERE
PERSONAL INJURY, DEATH, AND/OR EQUIPMENTDAMAGE. SERVICE PER-
SONNELMUSTBE QUALIFIEDTOPERFORMELECTRICALAND/OR MECHANI-
CALSERVICE.
1 =I

Section 2. Specifications
GENERATOR
Type ................................................ RevolvingField,4-Pole, Self-Excited
Standby Ratings:
60 Hertz, 6.5 MCE
........................................... 6.5 kW, (6.5 kVA @ 1.0 PF)
60 Hertz, 4.5 MCE
........................................... 4.5 kW, (4.5 kVA @ 1.0 PF)
50 Hertz, 5.0 MCE ........................................... 5.0 kW, (5.0 kVA @ 1.0 PF)
AC VoltageRegulation
............................................................. +5%
Frequency Regulation ...................................................... .5% (3 Hertz)
ENGINE
EngineType ............................................ Onan@MCE, 2-Cylinder Opposed
EngineSpeed (r/min)
......................................................... I800/1500
Exhaust Outlet HoseSize
............................................... .2.0 in. (50.8 mm)
Fuel..
.............................................................. Unleaded, 88 octane
FuelInletSize..
............................................................ .1/4-18 NPT
FuelConsumption, Average
@ FullLoad:
60 Hertz, 6.5 MCE
.................................................... 1.3 gph (5.0 Lph)
60 Hertz, 4.5 MCE
.................................................... 1.6 gph (6.1 Lph)
50 Hertz, 5.0 MCE .................................................... 1.1 gph (4.2 Lph)
FuelInletSize..
......................................................... 1/4-18 NPTF
FuelReturnOutletSize
................................................... .1/8-27 NPT
MinimumColdCrankingAmps
@ 0°F (-18°C). ...................................... 360
Voltage
........................................................................... 12
Capacity, Heat ExchangerSystem.. .................................... .10 Quarts(9.4 L)
Heat Rejection:
60 Hertz
@ Load, Block & Exhaust Manifold.. ............................ 800 BTU/min
50 Hertz @ Load, Block & ExhaustManifold.. ............................ 650 BTU/min
HeatExchangerSystem,ThermostatOpen
......................... .2.2 gpm (8.3 L/min)
Sea Water, HeatExchangerSystem
.............................. .3.0 gpm (11.4 L/min)
SeaWater CoolingSystem
...................................... -3.0 gpm (1 1.4 L/min)
Heat ExchangerSystem,ThermostatOpen
......................... .2.2 gpm (8.3 L/min)
SeaWater, HeatExchangerSystem
............................... .2.5 gpm(9.5 L/min)
SeaWater CoolingSystem
....................................... .2.5 gpm (9.5 L/min)
SeaWater Pump
Dry Lift, Maximum ............................................ 3 ft (0.9 m)
TotalAir Required(Generator Coolingand Combustion):
60 Hertz..
.................................................... .146 ft3/min (4.1 m3/min)
50 Hertz .................................................... 120cu. ft./min (3.4 m3/min
EngineOil Capacitywith Filter
............................................ .3Quarts (2.8 L)
Battery Requirements:
CoolingSystem:
CoolingFlow Rate, 60 Hertz:
CoolingFlow Rate,
50 Hertz:
2-1

Section 3. Location and Mounting
LO CAT1 ON
Generatorsetlocationispreferableinthesameroomor
compartmentasthepropulsionengine,asthisisusually
a
well ventilatedarea,insulated,closetothefuelsupply
andisthecenterofelectricalloaddistribution. However,
a generator set cannot be installed in the propulsion
enginecompartmentunlessspecificconditionsaremet.
USCG regulation 33CFR183 pertainsto gasoline fuel
systems, and requiresa generator set operating in a
gasoline fuel environment to be “ignition protected.”
This means aset capableof operatinginan explosive
environmentwithoutignitingthatenvironment. Properly
installed and operated, the
MCE generator set can
operate inan explosive environment.
Gasolinefireorexplosioncanresult
inseverepersonaliniuryordeath.
Do
notinstallagasolinegeneratorsetinthesameroomor
compartment
of a dieselpropulsionengineorgenerator
set. Thediesel unitmay not be ignifionprotected and
mayignitegasolinefumes.Besure
a gasolinegenerator
set
is insfalledin its own room or compartment.
MOUNT1 NG
Thefloormustbeflatandgivesupportdirectlyunderthe
genset mounting points (Figures
3-1 and 3-2). A one
inch
(25 mm) clearance aroundthe unit is requiredto
permit rockingon its mounts without restraint; and
4.2
inches (106 mm) for servicingthe oil filter. Additional
spacemustbeallowedforproperventilationforcooling
and combustion,as well as serviceaccess.
Also allow
accessfor periodicmaintenancesuchasoilfill,coolant
fill, spark plug replacement, etc. The entire exhaust
system must be accessible
so a periodic visual and
audiblecheckfor leakagecanbemadebytheoperator.
Install
two hold-downclampsortwothroughboltstothe
drippanon bothsidesof thegeneratorset.Tightenthe
clamps securelyto the mounting base with bolts and
flatwashers.
Selecta locationthat will allow adequate space on all
sidesfor ventilationand servicingtheset, preferablyon
andparallelwiththekeelorvessel center line. Keepthe
generator set awayfrom livingquarters, andaway from
bilgesplash and vapors.
3-1

2
(i
I
3
FIGURE 3-1. DRIP PAN DIMENSIONS
DIMENSIONS IN (
4.k
"i"
) ARE METRIC
3-2

(HEAT EXCI
SIDE VIEW
NOTES I
I .DIMENSIONS IN t l ARE MILLIMETERS
2.DRY WEIGHT! 335 LBS (152 Kgl
COOLANT FILL
iANGER
MODEL ONLY)
C CONNECTION
.I2
(d HOLE(FARSIDE1
FRONl
IL FILL COOLANT FILL
(HEAT EXCHANGER MODEL ONLY1
1.19
4 I
/WET EXH! 1 ’ 18.04(30.2) {
20.43 4
l518.9)
2.00 ID
HOSE 20.25
(50.8) (458.31 4.18
(106.2)
OIL FILTER
REMOVAL
(514.3)
FIGURE 3-2. OUTLINE DRAWINGS
3-3

Section 4. Ventilation
GENERAL
Theinstallationofboatventilationsystemsmustmeetall
Coast Guardand
NFPA requirements. Establishingthe
correct
air flow quantity is particularlyimportantwith
small compartments under 1000cubicfeet
(28 m3), or
installationsinclosequarters. Ventilationsystemsmeet-
ingCoast Guard requirements for gasolineengines in
passenger vessels (Table 4-1) will normally suffice,
however specialconsiderationmust begivento com-
partment conditionsduring operation.
TABLE 4-1. PASSENGERVESSEL
VENTILATION REQUIREMENTS
SIZE
OF MINUTESREQUIRED
COMPARTMENT TO EXCHANGETOTAL
Cu. Ft. (m3) AIR VOLUME
Less than 500 (14) 2
500 to 1000 (14 to 28)
1000 to 1500(28 to 42)
1500 and Up (42 and Up)
3
4
5
REQUIREMENTS
Marinegeneratorsetsmusthaveairventilationforthree
very important reasons:
1. Toremoveflammableorotherharmfulgases. Coast
Guard regulations require power blowers in the
generator set and propulsionengine rooms be run
atleastfourminutespriortostartingtheengineand
during operation. The operator must also inspect
the engine room
for the presence of fuel vapors
prior to starting, especially when gasoline fueled
equipmentisused(seetextunderCoastGuardand
NFPA Requirements).
2. To provide engine combustion air and generator
coolingair.
CoastGuardregulationsrequirepower
exhausters in all installations, and one blower in
each exhaust duct. Exhausters must have an air
capacity
1-1 /2 to 2 timesthe minimum generator
set total air requirements. The MCE generator set
requiresatotaloperationminimumof 146cubicfeet
perminute (4.2 m3/min).
3. To control compartment temperature during
gensetoperation.
Thiswillavoidoverheatingwhich
can resultinshutdownfromvapor lock,engineand
related control component damage, and power
loss.
As a general rule, the operating environment
for a gasoline genset should not be higher than
14OOF (60OC) maximum. Lower temperatures are
recommended. Often an operating power blower
mayberequiredto maintaintemperaturewhenthe
gensetisoperating, especiallywhen theboat isnot
moving.
The compartment must have air inlets and outlets to
providethis air. Inletducts shouldhave cowlsor equi-
valentfittings of twicethearea of the duct, largerifthe
opening
is screened. Do not use recessed or flushed
inlets,or louveredtransom outlets.
Ifthegasolinefueltankisinaseparatecompartment,
it
also must beventilated.
COAST GUARD AND NFPA REQUIREMENTS
Bothorganizationsrequireat least two inletductsand
two outlet ducts extending to the bilge for gasoline
generator set installations in
a closed Compartment.
When not in a closed compartment, at leastone duct
shouldbe installedinthe fore section of the boat and
another aft. The
NFPA recommends a vent size of at
least two square inches per foot (42.3 cm2/m) of boat
beamfor totalinletarea andtotaloutetarea.
BoatsclassifiedaspleasurevesselsbytheCoastGuard
musthavesufficientventilationto eliminateaccumula-
tionofflammablegases. Boatsunder
65 feet (20 m) long
classifiedas passenger vessels requireventilationbe
sufficienttochangethe compartmentairwithinagiven
time interval(Table 4-1).
Forpassengervessels,theCoastGuardrecommendsa
mechanicalexhaustingsystemtomeettherequirement
in Table 4-1. The exhaust blower motors should be
outsidethe compartment.
If a gasolinefuel tank is in aseparate compartment, it
must be ventilated to the same requirements as the
enginecompartment.
4-1

Section 5. Cooling System
GENERAL
Throughout this manual, flotationwater drawn into the
boatforenginecoolingiscalledseawater. Water recircu-
latedthroughthe engineclosed systemiscalledcaptive
water. Thus, confusion is avoided with other generic
terms describing water use.
The
two typesof marinecoolingsystemscoveredinthis
manual are
heat exchanger and sea wafer cooling. An
explanation
of each system, and the advantages and
disadvantages of each are covered inseparate chapter
headings. The heat exchanger system is ordered most
often and is standard on the
MCE generator set Sea
water coolingisan available option.
System Plumbing
Toadequatelycoolthegeneratorsetunderallconditions,
the plumbing system must be properly planned and
installed. Excess lengths of plumbing increases flow
resistanceand results inreducedcooling.An air leak in
theseawaterintakewillreducecooling,causecorrosion,
and can even destroy the neopreneimpeller inthe
sea
water pump. The neoprene impeller must never be run
dry, andshould be primedbeforeinitialstart
Thewaterlineshouldhaveaminimuminsidediameterof
0.75 inch (1 9 mm). Forrunsover 20 feet (5.2 m), increase
thelineonepipesizeforeachadditional 10 feet (2.6 m) of
length.Waterlinescanbeeithercoppertubingorflexible
hose. Be sure a length of flexible hose is used at the
generator set connectiontoallowset movementandfor
noiseabatement
Unlesstheseawater isvery clean, Onanrecommendsa
water strainer or filter to protectthe sea water cooling
system. See Figure
5-1.
Onanhasahullstrainer(furnishedwithsomemufflerkits)
that can be used with a flush through-hull fitting. The
strainer(Figure
!SI), installedwiththeslotsparalleltothe
keel,helpspreventpressureorvacuumwhen theboatis
underway. Always useaflush-typeinletwith a hydrody-
namic marinemuffler.
The flush-fype through-hull wafer
inlef must have
an openingatleastas
lameas fhe wafer inlef line.
TO
GENERATOR
SET
RECOMMENDED
WATER STRAINER
OR FILTER
FLUSH THRU-
HULL FllllNG
STF
CROSS-SECTION
VlMl
HULL.
--WNER
CS-1312-1
FIGURE 5-1. SEA WATER INLET
Staggerthegeneratorsetwaterinlet so itisnotdirectlyin
linewithotherinlets. Notdoing
so canreducetheamount
of sea water available tothegenerator set when under-
wayandcauseoverheating. Never usescooptypewater
inletfittings with ahydrodynamicmuffler.
-1 Do not use scoop fype wafer inlet fit-
tings with a hydrodynamic muifler.
Forward
facing scoopscandevelopsuiiicienf rampres-
sure to force wafer past the generator sefs sea wafer
pump. Thiscanfloodfheexhausfsystemandfheengine
cylinders. This
happens when the generator set is not
running and theboat
is underway. Rear iacing scoops
develop vacuumwhichcanimpede
ding wafer flow.
HEAT EXCHANGERCOOLING
This coolingsystem,standard on thegenset, keepssea
water andthe resultingsedimentdeposits (salt, silt,etc.),
from the engine cooling jacket It also provides more
uniform coolingand temperature control inthe engine.
Seawater and captivewater arekeptseparated,andthe
enginewaterjacketstayscleanforoptimumheattransfer.
5-1

Figure 5-2 shows the flow directionof sea water and
captivewater. The sea water pump constantlyrenews
thecoolwater bathintheheatexchangerandexhaust
system. The captive water is circulated by a pump
through the engine block, heat exchanger, and the
exhaust manifold. The captive water temperature and
flow rateare controlled
by thermostats.
Eachgensethasarecoverytankkittobeinstalledinthe
captivecoolingsystem. Thetank (similar to automotive
application)isconnectedto the overflow fitting below
thepressurecap. Itkeepsthecaptivesystemfilled with
coolantwhich helpspreventcorrosion and sediment.
Thetankshouldbelocatedforeasychecking
of coolant
level, andfor serviceability.lnstallationinstructionsare
furnishedwith the kit.
BELT-DRIVEN SEA
WATER PUMP HEAT EXCHANGER
r-
I
FROM SEA
WATER INLET
The captivecoolingsystemshouldalwaysusea 50-50
mixture of ethyleneglycol and distilled water to help
prevent corrosion.See the lnstallation Checkout sec-
tionfor filling instructions.
If a heat exchanger other than the Onan standard is
installed, several precautionsarerequiredas follows:
Theheatexchangermustproperlycoolthegenera-
torsetunderallloadconditions.TheOnansystemis
designed to coolthesetatfull loadwithsea water
inlettemperatures up
to 1 OOOF (38OC). Extramargin
(10%) must be allowed for varying conditions of
pumps, coolantand scalebuildup.
Minimumcaptivewater andseawaterflowrequired
by the generator set must be met. The heat
exchangerwill also have minimum and maximum
flow requirementswhichmustbemetforcoolingat
its capacity. The generator set requirementsare
listedinthe
Specificafion section.
r*
I
I
t
I
I
I
I
.-*----
t
MANIFOLD
(MIXER)
EXHAUSTAND SEA
WATER OUTLET
TO MUFFLER
by Separate Pump
--P Captive CoolingWater
Circulatedby
cs1369
....
FIGURE 5-2. COOLANT FLOW, HEATEXCHANGER COOLINGSYSTEM
5-2

SEA WATER COOLING
The sea water coolingsystem isshown in Figure 5-3.
This system uses the belt-driven sea water pump to
directwater throughthe engine coolingsystemandout
theexhaustsystem.The electriccirculatingpump
is not
usedonthissystem. The engineblocks have adrilled
coolantbypassholetoallowsomecoolantflowregard-
lessofthermostatopening.Thisallowsforexhaustcool-
ing and protection of the pump. The sea water and
exhaust is disposed
of similarly as described in Heat
ExchangerCoolingwithahydrodynamicmuffler(above
or belowwater lineinstallation).
Theseawater comesintodirectcontactwiththeengine
coolingjacket, and this system should be avoided for
use in salt or contaminated water. Such water can
cause engineblockcorrosionand/or plugging; there-
fore, heatexchanger systems are recommended.
.
COMBINED COOLING SYSTEMS
Onandoesnotrecommendcombiningthegeneratorset
coolingsystemwiththe propulsionenginecoolingsys-
tem. This involvesa great amount of experience and
knowledgefor the installer, as wellas complete know-
ledge
of characteristicsof boththe generator set and
propulsionengines.
Propulsion engines use scoop-type
waterinlet fittings whichmustnot be
usedfora generator set witha hydrodynamicmuffler.
Whennotoperating,rampressurecanforcewaferpast
the generator set’s sea water pump and flood the
exhaust system. From here it can flow back, flooding
the engine cylinders and possibly the engine com-
partment.
BELT-DRIVEN SEA
WATER PUMP
EXHAUST
MANIFOU)
I
,- I EXHAUSTMANIFOLD /I\
FROM SEA I (MIXER) /I\
+
WATER INLET
I
re
I
EXHAUSTAND SEA
WATER OUTLET
TO MUFFLER
I
I
+
I
I
I
FIGURE 5-3. COOLANT FLOW. SEA WATER COOLING
5-3

Section 6. Exhaust System
GENERAL
Theinstallationof two water-cooled exhaustsystemsare
covered in this section. They are below-loadwaterline
andabove-loadwaterline,andarecoveredundersepar-
ate headings.
All exhaust systems for water-cooled
marine installationsmust meet each of the following
requirements. Failureto meettheserequirements could
result in severe property damage, personal injury or
death.
b
The entireexhaust system must beaccessible so a
periodicvisualandaudiblecheckforleakagecanbe
made bythe operator.
0 The exhaustsystem must bewater cooled, andthe
water injected as near to the generator set as
possible.
0 All exhaust system sections preceding the point of
water injectionmust bewater jacketedor effectively
insulatedor shielded.
0 The exhaust line must be installedto prevent back
flowofwatertotheengineunderanyconditions; and
the exhaustoutlet mustbeabovetheloadwaterline.
Water backflow into the enginewilldamage
it
The generatorset exhaustsystem must not becom-
bined with the exhaust system of another
engine.
0 A flexible section of marine exhaust hose must be
used nearthe enginetoallowfor engine movement
and vibration during operation.
All exhaust system
hoses mustbeCERTIFIEDfor marine use.
0 Theexhaustsystem mustbeof sufficientsizetopre-
vent excessive back pressure. See Back Pressure
data inthissection.
Installexhaustthroughhullfittingaftof sink, shower
orother cabin drainstopreventbackflowof exhaust
gases into thevessel.
Material
UsematerialrecommendedbyABYC in “Safety Standard
for Small Crafi, ”Section P1. Theexhaust linemustbeat
leastas largeastheengineexhaustmanifoldoutlet
See
followingsection on Back Pressure.
Exhaustgas containscarbonmonox-
ide, an odorless, colorless, highly
poisonousgas thatpresents the hazard of severe
per-
sonal injuw or death. Place special emphasis on the
following:
0 Be sure the flexible exhausthose is designed and
certified
for marineexhaustline use.
Use two clampsat each end of all flexible exhaust
hose connections.
Do not make shatpbends in the exhausthose.
0 Position exhaust outlet to prevent backflow of
Use flexible hose designed and CERTIFIED for marine
exhaustlineuse. The mufflermustbeatthelowestpoint
of theentireexhaustsystem.Themufflertopshouldbeat
least 12 inches
(305 mm) below the exhaust manifold
outletIfitishigher,backflowofwatertowardthemanifold
ismorelikely.
Makesurethe hosedrainstowardthemufflerat
a grade
of
1 /2 inchper linealfoot (42 mm/m). An uphillsection
between the exhaust manifold and muffler can cause
backflow of water and is not permissible
- NO
EXCEPTIONS.
exhaust gasesinfothe vessel.
Be sure that the vertical rise of the exhaust hose mea-
suredfromthebottomofthemufflertoitspeakisnotmore
than
48 inches(1.2 m) as shown inFigure6-1.
Theexhausttubing(onbothaboveandbelowloadwater-
line installations) must be pitched downward to the
through-hulloutletfittingataminimumdowngradeof 112
inch per lineal foot
(42 mm/m). There must also be a
12-inch
(305 mm) minimumdrop from this peak to the
through-hull outlet fitting as shown in Figures 6-1 and
6-2.
Allowspacebetweenthemarinemufflerand its mounting
surface by use of spacers under the mountingflanges.
Thisallowsaircirculationunderthemuffleranddiscour-
ages condensation build-up.
6-1