Midea MWF-07CM User manual

0
Website: www.mideaaircon.com
Service manual
CAUTION
-BEFORESERVICINGTHEUNIT, READTHESAFETY
-PRECAUTIONSINTHISMANUAL.
-ONLYFORAUTHORIZEDSERVICEPERSONNEL.
MODELS: MWF-07CM
MWF-09CM
MWF-12CM
MWF-16CM
MWF-18CM
MWF-21CM
MWF-24CM

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CONTENTS
1. PREFACE
1.1SAFET PRECAUTIONS.................................................................................................................1
1.2INSULATIONRESISTANCETEST................................................................................................1
1.3FEATURES.....................................................................................................................................2
1.4CONTROLLOCATIONS................................................................................................................2
1.5OUTSIDEDIMENSIONS................................................................................................................2
2. INSTALLATION
2.1SELECTTHEBEST LOCATION...................................................................................................3
2.2CHECK OF INSTALLATION..........................................................................................................3
2.3HOW TO DRAIN.............................................................................................................................3
2.4HOW TO INSTALL.........................................................................................................................4
3.TROUBLESHOOTING
3.1PIPINGSSTEM..............................................................................................................................7
3.2TROUBLESHOOTINGGUIDE.......................................................................................................8
4. WIRING DIAGRAM................................................................................................................................10
5. EXPLODEDVIEW.................................................................................................................................14
6. SPAREPARTSLIST…..........................................................................................................................14
1.PREFACE
ThisSERVICEMANUALprovidesvariousservicing information,including the mechanicaland electrical parts,
etc.Thisroomairconditionerwasmanufactured and assembled underastrictqualitycontrolsystem.
The refrigerantischarged atthe factor. Besuretoread the safetyprecautionspriortoservicing theunit.
1.1SAFETPRECAUTIONS
1.When servicing the unit,set the POWERSWITCH toOFFand unplug the powercord.
2. Inspect the servicecordfordamage orwear.
Ifashort circuitisfound, replaceallpartswhichhavebeen overheated ordamaged bthe short circuit.
3. Afterservicing the unit, makean insulation resistancetest toprotectthe customerfrombeing exposed to
shock hazards.
1.2INSULATIONRESISTANCETEST
1. Unplug the powercordand connect ajumperlead between the two(2)livepins.
2. The grounding conductor(yellow/green)istobe open.
3. Measurethe resistancevaluewithan ohmmeterbetweenthe jumpedlead and eachexposed metallicpart
on the equipment at allthe positions(exceptOFF)ofthe ROTARSWITCH orPOWERSWITCH.
4. The value shouldbe over1M .

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1.3FEATURES
Designed forHEATPUMP.
Powerfulcooling &heating.
Slide-inand slide-outchassisforthe simple
installationand service.
Side air-intake,side cooled-airdischarge.
Washableone-touchfilterand easyremoved
panel.
Supercompact design.
Reliableand efficientrotarycompressoris
equipped.
Unique Quiet Design.
Freshairswitch.
1.4DIAGRAMPANEL
AUTOLOUVER
When theswitchison,thelouver motorwilloperateandbeginautolouver function.
When theswitchisoff, thelouver motorwill stop.
THERMOSTAT
Setthetemperature desired.
SELECTOR
Selecttheoperation functioninCOOL, HEATorFANONLYwith HIGH,MIDorLOWfan
speed.
TEST RUN
TurntheknobtothispositiontooperatetheunitinFORCEDCOOLING. Underthismode,
theunitwilloperateincooling immediately.
WAITTHREE MINUTES BEFORERESTARTING
To protectthecompressor,please doNOTrestarttheunitinCOOLINGorHEATING mode
in three minutes.
1.5OUTSIDEDIMENSIONS
Model A
(mm) B (mm) C (mm)
MWF-07CM
MWF-09CM 346 450 535
MWF-12CM 380 600 560
MWF-16CM
MWF-18CM 430 660 687
MWF-21CM
MWF-24CM 430 660 770

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2INSTALLATION
2.1SELECTTHEBESTLOCATION
1. Toavoidvibration and noise,makesurethe unitisinstalled securelyand firml.
2. Installthe unit wherethe sunlight doesnot shine directlyon theunit.Ifthe unit receives
directsunlight,buildan awning toshade the cabinet.
3. Thereshouldbe no obstacle,suchasafenceorwall, within50cmfromthe back of the
ambient becauseitwillpreventheat radiation ofthe condenser.
4. Restriction of outside airwillgreatlyreducethe cooling and heating efficiencyofthe air
conditioner.
5. Installthe unit on aslightanglesothat ancondensateformed will not enterthe room
(about 10mm or1/4bubblewithlevel).
6. Installthe unit withitsbottomportion 75~150cmabovethe floorlevel.
7. The powercordmust be connected toan independent circuit.The yellow/green wiremust
be grounded.
2.2CHECK OFINSTALLATION
The setting conditionsmustbe checked priortoinitialstarting.The undermentioned
itemsareespeciallyimportant checking pointswhen the installation isfinished.
1.Grounding wire(yellow/Green)isprovided inthe powercord.The wiremustbe
grounded.
2.Ensurethat the unitisconnected toasuitablyrated and dedicated circuit.
3.Toavoidvibration ornoise,makesurethe airconditionerisinstalled securely.
4.Avoidplacing furnitureof draperiesinfront ofthe airinlet and outlet.
2.3HOWTO DRAIN
The basepan maoverflowdue tohighhumidity.Todraintheexcess water,removethe drain
cap fromthe bottomof the unit(iffitted)and attachadrainhose(not supplied).
1.Takethe drainpan whichispacked withthe unit.
2.Removethe rubberplug fromthe bottomof the basepan (iffitted).
3.Installthe drainpan overthe area ofthe cabinetwhereyou removedtheplug,and
securewith2screwsprovided.

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4.Connectthe drainhosetothe outletlocated atthebottomofthe drainpan.You can
purchasethe drainhoseortubing locallytosatisfyourparticularneeds(Drainhoseis
n
o
t
s
u
p
p
li
e
d).
2.4HOWTO INSTALL
2.4.1 Installation of the housing
Step 1
Removethe airconditionerfromit'spackaging,removefixing screwsand slide the air
conditionerout ofit'shousing (RefertoInstallation Steps).
Step 2
Preparethe holeinthewall sothatthe bottomofthe housing iswell supported,the top
hasminimumclearanceand the airinletlouvershaveclearanceasshownbelowin
optionsAand B.Holesfromthe outside through tothe cavityshouldbe sealed.The
housing shouldslope downtowardsthe rearbabout5mm toallowwaterformedduring
operation todrain.
Step 3
Install the housing intothe wallandsecure.Ensurethefoamsealsarenotdamaged.
Flash, sealorfillgapsaround the inside and outside toprovide satisfactory appearance
and protection against the weather,insectsand rodents.

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2.4.2 Installation oftheunitintothehousing
1.Slide the unitintothe housing untilitisfirmlyagainst therearofthe housing. Careis
required toensurethe foamsealing stripson the housing remaininposition.
2.Connect the airconditionertothe powerand position excess cordlengthbeneaththe
airconditionerbase.
3.Engage the chassisfixing brackets
intothe bottomhousing railand
securetothe basewiththe screw
provided.
4.Removethe frontpanelfromit's
carton and plasticbag and fitasper
the installation instruction.
5.Switchunit on. Checkforoperation of
the unitand check forvibration inthe
installation.
6.Fitthe drainpan tothe housing and
run adrainline toasuitablelocation if
required.
2.4.3 Installation oftheunitintothewall

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2.4.4 Installation steps
Step 1. Removethe front paneland the airfilter
1.Holdthe slotunderthe frontpanel,then upliftitoutwards,and removethe frontpanel
(See Fig.1).
2.Pinchthe handleunderthe airfilterand makethe airfilterarched,removeitfromthe
slotfromunderside toupside (See Fig.2).
Step 2. Removethe frame.
1.Removethe twofixingscrewsfromthe frame(See Fig.3).
2.Graspthe left cornerof the frame'sunderside, then loosen the frame(See Fig.4).
Step 3.Installation.
1.Removethe twofixingscrewson the chassisfixing brackets, then removethechassis
fixing brackets(See Fig.5).
2.Graspthe handleon the chassis
and carefullyslide the air
conditionerout of the cabinet(See
Fig.6).
3.Removeshippingpad fromaround
compressorbeforeoperation and
makesurethe discharge pointsto
the drainpan arealigned before
the chassisispushed intothe
cabinet (SeeFig.7).
4.Pushthe unit chassisintothe
cabinet (SeeFig.8).
5.Install the twochassisfixing
bracketsusing the twofixing
screws(See Fig.5).
Step 4.Installthe frame.
1.Install the framemaking surenot
tointerferewiththe temperature
sensorcable(See Fig.9).
2.Fixthe screwson the frame(See
Fig.3).

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Step 5.Installthe airfilterand front panel.
1.Install the airfilterintothe frame'sslotfromupside tounderside (See Fig.2).
2.Hang the frontpanelon the frame'sbuckle,then press the frontpanelintothe frame's
slot until you hearaclick(See Fig10).
3TROUBLESHOOTING GUIDE
3.1REFRIGERATIONCCLEDIAGRAM
Thefigurebelowisabriefdescription oftheimportantcomponentsandtheirfunctioninwhatis
called the refrigeration system.
Thiswillhelptounderstand the refrigeration cycleand theflowofthe refrigerantinthe cooling
cycle.

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3.2TROUBLESHOOTINGGUIDE
Ingeneral,possibletroubleisclassified inthree kinds.One iscalled Starting Failurewhichiscaused from
an electricaldefect, anotherisineffectiveAirConditioning caused badefectinthe refrigeration circuitand
improperapplication,and the otheriscalledthe StructureDamage.
ROOMAIRCONDITIONERVOLTAGELIMITS:
NAMEPLATERATING MINIMUM MAXIMUM
220~240V 196V 253V
PROBLEM POSSIBLECAUSE REMED
No power Check voltage at electricaloutlet. Correctif none.
Powersupplycord Check voltage atthe powercordterminal.Replacethe
powercordif none.
Wiredisconnected or
connection loose Connect wire. Refertowiringdiagramforterminal identification. Repairorreplacelooseterminal.
Mainswitchfailure Check and replacethemainswitchiffailure.
Capacitor(Discharge
capacitorbefore
testing)
Test capacitor.
Replaceif notwithin+/-10% ofmanufacture'srating.
Replaceif shorted, open ordamaged.
Fan motorwillnot
run.
Will notrotate
Fan blade hitting shroud orblowerhitting scroll. Realign
assembly.
Check fan motorbearings. Replacethe motorifmotorshaft
do not rotate.
Check voltage. Call an electrician if notwithinlimits.
Test capa
citor.
Replaceif notwithin+/-10% ofmanufacture'srating.
Check bearings. Replacethe motorif thefan blade cannot
rotatefreely.
Fan motorruns
intermittently Cycleson overload.
Payattention toanychange fromhigh speed tolowspeed.
Replacethe motorif the speed doesnot change.
Fan Replacethe fanif cracked, outofbalance, orpartially
missing.
Blower Replacethe blowerifcracked, outof balance, orpartially
missing.
Loosescrews Tighten them.
Fan motornoise.
Wornbearings Replacethe motorifknocking soundscontinue when running orloose, orthemotorhumsornoiseappearstobe internal
whilerunning.
The compressor
not tostop even
the room
temperaturehas
got tothe setting
temperature.
Thermostat Check and replaceif the thermostatisdamaged.

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Airfilter Clean orreplaceif restricted.
Vent. door Closeif open.
Unit undersized Determine if the unitisproperlysized forthe area tobe
cooled orheated.
Condenserand
Evaporator Clean orreplaceif restricted.
Fan motor Check the fan capacitorand replaceif notwithin+/-10% of
manufacturesrating.
Roomstructure Takepropermeasurestomakethe doorand windows
sealed well if gap isfound.
Airflow Clean orremoveif anybarrierisfound toblockthe
inlet/outletwind flowofthe unit.
Sunlight Add aawning if the condenserisexposed tothe sunlight.
Lessrefrigerant Check the tubesforreasonsofleakage. Recyclethe
refrigerant, correctthe leakage pointsand recharge.
Capillary tube Regulatethe flowif capillarytube and makethe evaporating temperatureappropriateif theevaporatorisfrosted. Replace
if blocked.Repairjointifleaking.
Compressor
The inletand outletvalveof the compressorisdamaged,
making the lowpressureconnected withthe highpressure.
The refrigerating systemcannot producehighpressureand
lowpressure. Replacethe compressorafterchecking forthe
reason.
Heat sources Reduceiftoo many.
reversevalve
The sealinvalveisdamaged,making the lowpressure
connected withthe high pressure. The refrigerating system
can not producehigh pressureand lowpressure. Replace
the reversevalveafterchecking forthereason.
Insufficient
cooling or
heating.
Drainage The drainage isblocked.Itwillincreasethe efficiencyin coolingmode,but will causethe condensertofrostinheating
mode.
Refrigerant The amount of the refrigerantistoo much, making the compressorload too big. Recycleand recharge the
refrigerantafterchecking forthe reason.
Stop instantly
afterstartup. Compressor The compressorisseized. Replaceafterchecking forthe
reason.
No power Check the voltage. Callan electrician if no withinthe limit.
Wiring Check the terminals. Repairand correctifloose.
Temperaturesetting Check and adjust the thermostat.
Mainswitchsetting Check and adjust the mainswitchsetting.
Reversevalvewire Check the resistanceofreversevalvewire. Replacethewire
if short, open ordamaged.
No coolingor
heating.
Reversevalve Ifthe reversevalveisblocked, theheating modewillnot perform. Replacethe reversevalveafterchecking the
reason.

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Voltage Check voltage. Call SupplyAuthorityif notwithinlimits.
Wiring
Check the wireconnections, ifloose, repairorreplacethe
terminal.If wiresareoff,refertowiring diagramfor
identification, and replace. Checkwirelocations. Ifnotper
wiring diagram, correct.
Mainswitchfailure Check and replacethemainswitchiffailure.
Capacitor(Discharge
capacitorbefore
testing)
Check the capacitor.
Replaceif notwithin+/-10% ofmanufacturersrating.
Replaceif shorted, open, ordamaged.
Thermostat Check the thermostat setting if not at the coolest (incooling
mode)orthe warmest (inheating mode).Set itif not.
Compressorwill
not run whilefan
motorruns.
Compressor Check the compressorforopen circuitorground.If open or
grounded, replacethe compressor.
Excessivenoise. Coppertubing Removethe cabinetand carefullyrearrange tubing notto
contact cabinet,compressor, shroudand barrier.
Powersupply The inputpowersupplyvoltage istoo low. Call an electrician
if not withinlimits.
The unitstarts
and stops
frequently. Outdoortemperature Whenthe outdoortemperatureistoo high, thecompressor
willprotect.
4WIRING DIAGRAM
4.1Formodels:
MWF-07CM MWF-09CM

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4.2Formodels:
MWF-12CM
4.3Formodels:
MWF-16CM

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4.4Formodels:
MWF-18CM

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4.5Formodels:
MWF-21CM MWF-24CM
5EXPLODEDVIEWS
(See attachedfiles)
6SPECIFICATIONS
(See attachedfiles)