OperatingGuide
TermixVMTD-FMIX-I
1.0TableofContents
1.0TableofContents.............................................1
2.0Functionaldescription......................................2
3.0Safetynotes.....................................................3
3.1SafetyNotes–general............................................3
4.0Mounting........................................................4
4.1Mounting...........................................................4
4.2Start-up..............................................................6
4.3Electricalconnections.............................................7
5.0Design.............................................................8
5.1Design...............................................................8
5.2Schematicdiagram................................................9
6.0Controls..........................................................10
6.1Heatingcircuit......................................................10
6.2DHWtemperaturecontrol........................................13
6.3Other.................................................................13
6.4Extras................................................................15
6.5Maintenance........................................................15
7.0Troubleshooting..............................................16
7.1Troubleshootingingeneral......................................16
7.2TroubleshootingDHW............................................16
7.3TroubleshootingHE...............................................17
7.4Disposal.............................................................18
8.0Declaration......................................................19
8.1Declarationofconformity........................................19
DanfossHeating
VI.GP .W4.02/LUK40250
DEN-GT
1
OperatingGuideTermixVMTD-FMIX-I
2.0Functionaldescription
Districtheatingsubstationfordirectheatingand
instantaneousdomestichotwaterwiththermostaticcontrol.
Designedforwall-mounting.
Application
TheTermixVMTD-FMIX-Iisacompletesolutionwithbuilt-in
waterheaterandheatingsystemwithdifferentialpressurecontrol
andmixingloop.TheTermixVMTD-FMIX-Iisapplicableforfor
single-familyhousesandfordecentralizedsystemsinmulti-family
houses.
Districtheating(DH)
Thesubstationisprefabricatedwithadifferentialpressure
controller,ttingpieceandsensorpocketforinsertionofa
heatmeteraswellasstrainerandballvalves.Furthermorethe
substationisdeliveredwithamixingloopincludingpump,controls
andnon-returnvalve.
Heating(HE)
Theheatingcircuitisdesignedfordirectconnection.The
differentialpressurecontrollersetstheoptimumoperation
conditionsforradiatorthermostatsinordertoenableindividual
temperaturecontrolineachroom.Themixingloopcreatesa
suitabletemperaturelevele.g.foroorheating.Inordertoenable
atimedependenttemperaturecontrolprogram,azonevalvewith
actuatorandaroomthermostatcanbeincludedasanoption.
Domestichotwater(DHW)
Thedomestichotwaterispreparedintheheatexchangerand
theheatexchangerandthetemperatureisregulatedwithaow
compensatedtemperaturecontrollerwithintegrateddifferential
pressurecontroller.TheheatexchangercoolsouttheDHwater
veryefciently,therebycreatinganexcellentoperatingeconomy.
TheDanfossIHPTvalveensuresastablehotwatertemperature
byvaryingloads,supplytemperaturesandbyhighandvarying
differentialpressurewithouttheneedforreadjustingthevalve.
Thisprotectstheheatexchangeragainstoverheatingandlime
scaleformation.FurthermoretheIHPTvalvehasanintegrated
idletemperaturecontroller,whichkeepsthehousesupplyline
warm.Thisshortensthewaitingperiodsduringsummerwhen
theheatingsystemisinreducedoperation,whichisidealwhere
highcomfortisrequested.
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DanfossHeating
OperatingGuideTermixVMTD-FMIX-I
3.0Safetynotes
3.1SafetyNotes–general
Thefollowinginstructionsrefertothestandarddesignof
substation.Specialversionsofsubstationsareavailableon
request.
Thisoperatingmanualshouldbereadcarefullybeforeinstallation
andstart-upofthesubstation.Themanufactureracceptsno
liabilityfordamageorfaultsthatresultfromnon-compliancewith
theoperatingmanual.Pleasereadandfollowalltheinstructions
carefullytopreventaccidents,injuryanddamagetoproperty.
Assembly,start-upandmaintenanceworkmustbeperformedby
qualiedandauthorizedpersonnelonly.
Pleasecomplywiththeinstructionsissuedbythesystem
manufacturerorsystemoperator.
Corrosionprotection
Allpipesandcomponentsaremadeofstainlesssteelandbrass.
Themaximumchloridecompoundsoftheowmediumshouldnot
behigherthan150mg/l.
Theriskofequipmentcorrosionincreasesconsiderablyifthe
recommendedlevelofpermissiblechloridecompoundsis
exceeded.
Energysource
Thesubstationisdesignedfordistrictheatingastheprimary
sourceofenergy.However,alsootherenergysourcescanbeused
wheretheoperatingconditionsallowitandalwaysarecomparable
todistrictheating.
Application
Thesubstationisdesignedtobeconnectedtothehouse
installationinafrost-freeroom,wherethetemperaturedoesnot
exceed50°Candthehumiditydoesnotexceed60%.Donotcover
orwallupthesubstationorinanyotherwayblocktheentrance
tothestation.
Choiceofmaterial
Choiceofmaterialsalwaysincompliancewithlocallegislation.
Safetyvalve(s)
Werecommendmountingofsafetyvalve(s),however,alwaysin
compliancewithlocalregulations.
Connection
Thesubstationmustbeequippedwithfeaturesthatensurethat
thesubstationcanbeseparatedfromallenergysources(also
powersupply).
Emergency
Incaseofdangeroraccidents-re,leaksorotherdangerous
circumstances-interruptallenergysourcestothestationif
possible,andseekexperthelp.
Incaseofdiscolouredorbad-smellingdomestichotwater,closeall
shut-offvalvesonthesubstation,informtheoperatingpersonnel
andcallforexperthelpimmediately.
Storage
Anystorageofthesubstationwhichmaybenecessarypriorto
installationshouldbeinconditionswhicharedryandheated.
Authorizedpersonnelonly
Assembly,start-upandmaintenanceworkmustbeperformedby
qualiedandauthorizedpersonnelonly.
Pleaseobserveinstructionscarefully
Toavoidinjurytopersonsanddamagetothedevice,itisabsolutely
necessarytoreadandobservetheseinstructionscarefully.
Warningofhighpressureandtemperature
Beawareoftheinstallation’spermissiblesystempressureand
temperature.
Themaximumtemperatureoftheowmediuminthesubstationis
120°C.
Themaximumoperatingpressureofthesubstationis10bar.PN16
versionsareavailableonenquiry.
Theriskofpersonsbeinginjuredandequipmentdamagedincreases
considerablyiftherecommendedpermissibleoperatingparameters
areexceeded.
Thesubstationinstallationmustbeequippedwithsafetyvalves,
however,alwaysinaccordancewithlocalregulations.
Warningofhotsurface
Thesubstationhasgothotsurfaces,whichcancauseskinburns.
Pleasebeextremelycautiousincloseproximitytothesubstation.
Powerfailurecanresultinthemotorvalvesbeingstuckinopen
position.Thesurfacesofthesubstationcangethot,whichcancause
skinburns.Theballvalvesondistrictheatingsupplyandreturnshould
beclosed.
Warningoftransportdamage
Beforesubstationinstallation,pleasemakesurethatthesubstation
hasnotbeendamagedduringtransport.
IMPORTANT-Tighteningofconnections
Duetovibrationsduringtransportallangeconnections,screwjoints
andelectricalclampandscrewconnectionsmustbecheckedand
tightenedbeforewaterisaddedtothesystem.Afterwaterhasbeen
addedtothesystemandthesystemhasbeenputintooperation,
re-tightenALLconnections.
DanfossHeating
VI.GP .W4.02/LUK40250
DEN-GT
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OperatingGuideTermixVMTD-FMIX-I
4.0Mounting
4.1Mounting
Installationmustbeincompliancewithlocalstandardsand
regulations.
Districtheating(DH)-Inthefollowingsections,DHreferstothe
heatsourcewhichsuppliesthesubstations.Avarietyofenergy
sources,suchasoil,gasorsolarpower,couldbeusedasthe
primarysupplytoDanfosssubstations.Forthesakeofsimplicity,
DHcanbetakentomeantheprimarysupply.
Connections:
1.Optionalhotwatercirculation(HWC)
2.Districtheating(DH)supply
3.Districtheating(DH)return
4.Coldwatermains(CWM)
5.Domesticcoldwater(DCW)
6.Domestichotwater(DHW)
7.Heating(HE)supply
8.Heating(HE)return
Connectionsizes:
DH+HE:
G¾”(int.thread)
CWM+DCW+DHW:
G¾”(int.thread)
Dimensions(mm):
Withoutcover:
H770xW535xD150
Withcover:
H800xW540xD242
Weight(approx.):25kg
Authorizedpersonnelonly
Assembly,start-upandmaintenanceworkmustbeperformedby
qualiedandauthorizedpersonnelonly.
Thepipeplacementcandeviatefromtheshowndrawing.Pleasenote
themarkingsonthestation.
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VI.GP .W4.02/LUK40250
DanfossHeating
OperatingGuideTermixVMTD-FMIX-I
4.1.1Installation
Mounting:
Adequatespace
Pleaseallowadequatespacearoundthesubstationformounting
andmaintenancepurposes.
Orientation
Thestationmustbemountedsothatcomponents,keyholes
andlabelsareplacedcorrectly.Ifyouwishtomountthestation
differentlypleasecontactyoursupplier.
Drillings
Wheresubstationsaretobewall-mounted,drillingsareprovided
inthebackmountingplate.Floormountedunitshavesupport.
Labelling
Eachconnectiononthesubstationislabelled.
Beforeinstallation:
Cleanandrinse
Priortoinstallation,allsubstationpipesandconnectionsshouldbe
cleanedandrinsed.
Tightening
Duetovibrationduringtransport,allsubstationconnectionsmust
becheckedandtightenedbeforeinstallation.
Unusedconnections
Unusedconnectionsandshut-offvalvesmustbesealedwitha
plug.Shouldtheplugsrequireremoval,thismustonlybedoneby
anauthorizedservicetechnician.
Installation:
Strainer
Ifastrainerissuppliedwiththestationitmustbettedaccording
toschematicdiagram.Pleasenotethatthestrainermaybe
suppliedloose.
Connections
Internalinstallationanddistrictheatingpipesconnectionsmustbe
madeusingthreaded,angedorweldedconnections.
Keyholeformounting.
DanfossHeating
VI.GP .W4.02/LUK40250
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OperatingGuideTermixVMTD-FMIX-I
4.2Start-up
Start-up,Heatingwithmixingloop
Start-up:
1:Pumpspeed
Setthepumptohighestspeedbeforestart-up.
2:Startpump
Startthepumpandheatthroughthesystem.
3:Openshut-offvalves
Theshut-offvalvesshouldthenbeopenedandtheunitobserved
asitentersservice.Visualcheckingshouldconrmtemperatures,
pressures,acceptablethermalexpansionandabsenceofleakage.
Ifthesystemoperatesinaccordancewithdesign,itcanbeput
toregularuse.
4:Ventsystem
Switchoffthepumpandventtheinstallationaftertheradiators
havebeenwarmedup.
5:Adjustpumpspeed
Setthepumptothelowestspeedconsistentwithcomfortand
electricityconsumption.
Normallythechange-overswitchissetinthemidposition(default).
Howeverforsystemswithunderoorheatingorsinglepipeloop
systems,itmaybenecessarytoturnthechange-overswitch
upwards.
Higherpumpspeedsareonlyusediftheheatingrequirement
increases.
Re-thightenconnections
Afterwaterhasbeenaddedtothesystemandthesystemhasbeen
putintooperation,re-tightenALLconnections.
Pump
Thepumpmustbeswitchedoffduringsystemll.
Underoorheating:
Pumpstopfunction
Ifthesubstationisusedinconnectionwithunderoorheating,the
circulationpumpmustbeconnectedtothepumpstopfunctionin
theunderoorheatingcontroller.Thepumpmustbestoppedif
allunderoorheatingcircuitsareclosed.
Warranty
Ifthisisnotpossible,thenowmustbecontinuedthroughthe
by-pass.Failingthis,thepumpwillbeatriskofseizureandany
remainingwarrantywillbewithdrawn.
Summeroperation:
Switchoffpump
Insummerthecirculationpumpmustbeswitchedoffandthe
shut-offvalvetoHEsupplyclosed.
Runningpumpbi-weekly
Itisrecommendedtostartupthecirculationpump(for2minutes)
onceamonthduringsummer;theshut-offvalveoftheHEsupply
mustbeshut.
Electroniccontroller
Mostelectroniccontrollerswillstartupthepumpautomatically
(pleasenotemanufacturer´sinstructions).
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VI.GP .W4.02/LUK40250
DanfossHeating
OperatingGuideTermixVMTD-FMIX-I
4.3Electricalconnections
Beforemakingelectricalconnections,pleasenotethe
following:
Safetynotes
Pleasereadtherelevantpartsofthesafetynotes.
230V
Thesubstationmustbeconnectedto230VACandearth.
Potentialbonding
Potentialbondingshouldbecarriedoutaccording
to60364-4-41:2007andIEC60364-5-54:2011.
Bondingpointonthemountingplatebelowrightcornermarked
withearthsymbol.
Disconnection
Thesubstationmustbeelectricallyconnectedsothatitcanbe
disconnectedforrepairs.
Outdoortemperaturesensor
Outdoorsensorsshouldbemountedsoastoavoidexposureto
directsunlight.Theyshouldnotbeplacedclosetodoors,windows
orventilationoutlets.
Theoutdoorsensormustbeconnectedtothestationonthe
terminalblockundertheelectroniccontrol.
Authorizedelectrician
Electricalconnectionsmustbemadebyanauthorizedelectricianonly.
Localstandards
Electricalconnectionsmustbemadeinaccordancewithcurrent
regulationsandlocalstandards.
DanfossHeating
VI.GP .W4.02/LUK40250
DEN-GT
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OperatingGuideTermixVMTD-FMIX-I
5.0Design
5.1Design
Yoursubstationmightlookdifferentthanthesubstationshown.
Designdescription
B
Heatexchanger,DHW
14
Sensorpocket,energymeter
N
Circulationconnection
31
Differentialpressurecontroller
2
Singlecheckvalve
41A
Fittingpiece,coldwatermains
7
Thermostaticcontroller,HE
41BFittingpiece,energymeter
9
Strainer
63
Sieve
10
Circulatorpump
74
IHPTcontroller,DHW
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DanfossHeating
OperatingGuideTermixVMTD-FMIX-I
5.2Schematicdiagram
DHW
DCW
CWM
DH
Supply
HE
Supply
DH
Return
HE
Return
Yoursubstationmightlookdifferentthantheschematicdiagramshown.
Schematicdescription
B
Heatexchanger,DHW
10
Circulatorpump
39
Connectionclosed
2
Singlecheckvalve
14
Sensorpocket,energymeter
41A
Fittingpiece,coldwatermains
7
Thermostaticvalve
18
Thermometer
41BFittingpiece,energymeter
9
Strainer
31
Differentialpressurecontroller
63
Sieve
74
IHPTcontroller
DHW:DomesticHotWater
DCW:
DomesticColdWater
CWM:
ColdWaterMains
DHSupply:DistrictHeatingSupply
DHReturn:DistrictHeatingReturn
HESupply:HeatingSupply
HEReturn:HeatingReturn
5.2.1Technicalparameters
Technicalparameters
Nominalpressure:PN10(PN16versionsareavailableonenquiry)
Max.DHsupplytemperature:
120°C
Min.DCWstaticpressure:
1.0bar
Brazingmaterial(HEX):
Copper
Heatexchangerstestpressure:30bar
Soundlevel:≤55dB
DanfossHeating
VI.GP .W4.02/LUK40250
DEN-GT
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OperatingGuideTermixVMTD-FMIX-I
6.0Controls
6.1Heatingcircuit
6.1.1Differentialpressurecontroller
Thedifferentialpressurecontrollersmoothsouttheuctuationsin
pressurearrivingfromthedistrictheatingnetwork.Theoperating
pressureinthesubstationisthusheldsteady.
6.1.2HEtemperaturecontrol
TheHEowtemperatureintheheatingcircuitiscontrolledbythe
HEtemperaturecontroller.
6.1.3RAVKcontroller
RAVKcontroller(25-65°C).Thetemperaturesettingisasfollows:
1=25°C
2=35°C
3=45°C
4=55°C
5=65°C
Thevaluesareintendedasaguide.
Thermostaticcontrol
ThetemperatureoftheHEowlineisadjustedasfollows:
Toincreasetemperature,turnthehandleonthethermostatic
controllertoselectahighernumber.
Todecreasetemperature,turnthehandleonthethermostatic
controllertoselectalowernumber.
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VI.GP .W4.02/LUK40250
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OperatingGuideTermixVMTD-FMIX-I
6.1.4TP7000
TP7000electronic7dayprogrammableroomthermostat.
Signalsfromtheroomthermostatcanbeusedtocontrolzone
valves.
6.1.5CirculatorpumpUPM3
UPM3Pumpscanbecontrolledinconstantpressure,proportional
pressureorconstantspeedmodedenedbythemeansofasmart
userinterface.
Thevariablespeedmodulatingmodesallowthepumptomatchits
performancetothesystemrequirements,helpingtoreducenoise
whenthermostaticvalvesareclosingdown.
EnergylabellingclassA
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OperatingGuideTermixVMTD-FMIX-I
6.1.6GrundfosUPM3AUTOLinstructions
Controlmode
Youcanswitchfromtheperformanceviewtothesettingsviewbypressingthepushbutton.Thesettingsviewshowswhichmode
controlsthecirculator.After2seconds,thedisplayswitchesbacktoperformanceview.
Ifyoupressthebuttonfor2to10seconds,theuserinterfaceswitchesto"settingselection"iftheuserinterfaceisunlocked.Youcan
changethesettingsastheyappear.Theselectionofthecontrolmodedependsonthesystemtypeandtheallocationofpressurelosses.
Ifyoupressthekeylockformorethan10seconds,youcantogglebetweenenabling/disablingthekeylockfunction.
Function
Recommendedfor
Green
YellowYellowYellowYellow
Proportionalpressure1
1-pipesystems
µµ
Proportionalpressure2
µµµ
Proportionalpressure3
2-pipesystems
µµµµ
Constantpressure1
Underoorheating
µµ
Constantpressure2
µµµ
Constantpressure3
µµµµ
ConstantCurve1
µµµ
ConstantCurve2
µµµµ
ConstantCurve3
µµµµµ
ConstantCurveMax.
µµµµ
Operationstatus
Function
Recommendedfor
Green
YellowYellowYellowYellow
Standby**OnlyPWMcontrolled
µ
0%≤P1≤25%
µµ
25%≤P1≤50%
µµµ
50%≤P1≤75%
µµµµ
75%≤P1≤100%
µµµµµ
Alarmstatus
Function
Recommendedfor
RedYellowYellowYellowYellow
Blocked
µµ
Supplyvoltagelow
µµ
Electricalerror
µµ
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DanfossHeating
OperatingGuideTermixVMTD-FMIX-I
6.2DHWtemperaturecontrol
DHWtemperaturecontrol
TherearevarioustypesofDHWtemperaturecontrolusedin
Danfosssubstations.
DHWtemperatureshouldbeadjustedto45-50°C,asthisprovides
optimalutilisationofDHwater.AtDHWtemperaturesabove55°C,
thepossibilityoflimescaledepositsincreasessignicantly.
6.2.1IHPT180controller(45–65°)
IHPTisaself-actingow-compensatedtemperaturecontrollerwith
integrateddifferentialpressurecontroller.
TheIHPToperatesatitsbestatDHsupplytemperaturesofupto
100°C.
Byturningthehandlefortemperaturesettingin(+)direction
thesettingisincreased,byturningitin(-)directionthesettingis
decreased.
Turns*
Scale
DHWTemperatureSetting[°C]
0
7
64
1
661
2
5
58
3
455
4
352
5
248
6
144
7
043
*Startposition:Handleturnedfullyin(+)direction.
Thevaluesareintendedasaguide.
6.3Other
6.3.1Safetyvalve
Thepurposeofthesafetyvalveistoprotectthesubstationfrom
excessivepressure.
Theblow-offpipefromthesafetyvalvemustnotbeclosed.The
blow-offpipeoutletshouldbeplacedsothatitdischargesfreely
anditispossibletoobserveanydrippingfromthesafetyvalve.
Itisrecommendedtochecktheoperationofsafetyvalvesat
intervalsof6months.Thisisdonebyturningthevalveheadin
directionindicated.
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OperatingGuideTermixVMTD-FMIX-I
6.3.2Strainer
Strainersshouldbecleanedregularlybyauthorizedpersonnel.The
frequencyofcleaningwoulddependonoperatingconditionsand
themanufacturer’sinstructions.
6.3.3GTUPressureEqualizer
TheGTUPressureEqualizerabsorbstheexpansiononthe
secondarysideoftheTermixwaterheatersandcanbeusedasa
substitutetothesafetyvalve.
Furthermorethepressureequalizerabsorbsapossibleincreasein
pressure,soadischargeoutletisomitted.
TheGTUPressureEqualizermaynotbeappliedinsystemswithhot
watercirculation.
6.3.4Fittingpiece
Thesubstationisequippedwithattingpieceforenergymeter.
Assemblyofenergymeters:
1:Closeballvalves
ClosetheballvalvesonDHSupplyandDHReturn,ifthereiswater
onthesystem.
2:Loosennuts
Loosenthenutsonthettingpiece.
3:Removettingpiece
Removethettingpieceandreplaceitwiththeenergymeter.Do
notforgetthegaskets.
4:Tightenconnections
Aftermountingoftheenergymeterremembertocheckand
tightenallthreadedconnections.
Sensorpocket,energymeter
Thesensorsoftheenergymeterismountedinthesensorpockets.
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OperatingGuideTermixVMTD-FMIX-I
6.4Extras
6.4.1Circulationpipe
Thecirculationpipesetismounteddirectlyonthecontroller.
Thesetincludescirculationpipe,singlecheckvalveandtting.
Whenmountingthehotwatercirculationdirectlyonthecontroller
thehotwatercirculationtemperaturewillbeequaltotheidle
temperature.Theidletemperatureisafewdegreeslowerthanthe
setdomestichotwatertemperature.
6.5Maintenance
Thesubstationrequireslittlemonitoring,apartfromroutine
checks.Itisrecommendedtoreadtheenergymeteratregular
intervals,andtowritedownthemeterreadings.
RegularinspectionsofthesubstationaccordingtothisInstruction
arerecommended,whichshouldinclude:
Strainers
Cleaningofstrainers.
Meters
Checkingofalloperatingparameterssuchasmeterreadings.
Temperatures
Checkingofalltemperatures,suchasDHsupplytemperatureand
DHWtemperature.
Connections
Checkingallconnectionsforleakages.
Safetyvalves
Theoperationofthesafetyvalvesshouldbecheckedbyturning
thevalveheadintheindicateddirection.
Venting
Checkingthatthesystemisthoroughlyvented.
Inspectionsshouldbecarriedoutminimumeverytwoyears.
SparepartscanbeorderedfromDanfoss.Pleaseensurethatany
enquiryincludesthesubstationserialnumber.
Authorizedpersonnelonly
Assembly,start-upandmaintenanceworkmustbeperformedby
qualiedandauthorizedpersonnelonly.
DanfossHeating
VI.GP .W4.02/LUK40250
DEN-GT
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OperatingGuideTermixVMTD-FMIX-I
7.0Troubleshooting
7.1Troubleshootingingeneral
Intheeventofoperatingdisturbances,thefollowingbasicfeatures
shouldbecheckedbeforecarryingoutactualtroubleshooting:
•thesubstationisconnectedtoelectricity,
•thestrainerontheDHsupplypipeisclean,
•thesupplytemperatureoftheDHisatthenormallevel
(summer,atleast60°C-winter,atleast70°C),
•thedifferentialpressureisequaltoorhigherthanthenormal
(local)differentialpressureintheDHnetwork–ifindoubt,ask
theDHplantsupervisor,
•pressureonthesystem-checktheHEpressuregauge.
Authorizedpersonnelonly
Assembly,start-upandmaintenanceworkmustbeperformedby
qualiedandauthorizedpersonnelonly.
7.2TroubleshootingDHW
ProblemPossiblecauseSolution
Strainerinsupplyorreturnlineclogged.Cleanstrainer(s).
DHWcirculationpumpoutoforderorwith
toolowsetting.
Checkcirculationpump.
Defectiveorcloggednon-returnvalve.
Replace–clean.
Noelectricity.Check.
Wrongsettingofautomaticcontrols,ifany.Toadjustanelectroniccontrollerfor
DHW,pls.noteenclosedinstructionsfor
electroniccontroller.
Scalingoftheplateheatexchanger.
Replace–rinseout.
Defectivemotorizedvalve.Check(usemanualfunction)–replace.
Defectivetemperaturesensors.
Check–replace.
ToolittleornoDHW.
Defectivecontroller.
Check–replace.
DCWisbeingmixedwiththeDHW,e.g.in
adefectivethermostaticmixingvalve.
Check–replace. Hotwaterinsometapsbutnotinall.
Defectiveorcloggednon-returnvalveon
circulationvalve.
Replace–clean.
Taptemperaturetoohigh;DHWtapload
toohigh.
Thermostaticvalveadjustedtoatoohigh
level.
Check–set.
Scalingoftheplateheatexchanger.
Replace–rinseout. Temperaturedropduringtapping.
LargerDHWowthanthesubstationhas
beendesignedfor.
ReduceDHWow.
Thermostaticcontrolvalvedoesnotclose
TemperaturedifferencebetweenDH
supplyandDHWsetpointtoolow.
Lowerthesetpointtemperatureor
increasetheDHsupplytemperature.
Idletemperaturetoolow(forstations
equippedwithIHPT).
Setpointtoolow.Turnthermostatin(+)direction.
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VI.GP .W4.02/LUK40250
DanfossHeating
OperatingGuideTermixVMTD-FMIX-I
7.3TroubleshootingHE
ProblemPossiblecauseSolution
Toolittleornoheat.StrainercloggedinDHorHEcircuit
(radiatorcircuit).
Cleangate/strainer(s).
ThelterintheenergymeteronDHcircuit
clogged.
Cleanthelter(afterconsultingtheDH
plantoperator).
Defectiveorwronglyadjusteddifferential
pressurecontroller.
Checktheoperationofthedifferential
pressurecontroller–cleanthevalveseatif
required.
Sensordefective–orpossiblydirtinthe
valvehousing.
Checktheoperationofthethermostat–
cleanthevalveseatifrequired.
Automaticcontrols,ifany,wronglysetor
defective-possiblypowerfailure.
Checkifthesettingofthecontroller
iscorrect–seeseparateinstructions.
Checkthepowersupply.Temporary
settingofmotorto“manual”control–see
instructionsonautomaticcontrols.
Pumpoutofoperation.Checkifthepumpisreceivingpowerand
thatitturns.Checkifthereisairtrappedin
thepumphousing–seepumpmanual.
Thepumpissetattoolowspeedof
rotation.
Setthepumpathigherspeedofrotation.
Pressuredrop–thepressuredropon
theradiatorcircuitshowslowerthan
recommendedoperatingpressure.
Fillwateronthesystemandcheckthe
functioningofthepressureexpansion
vesselifrequired.
Airpocketsinthesystem.Venttheinstallationthoroughly.
Limitingofthereturntemperature
adjustedtoolow.
Adjustaccordingtoinstructions.
Defectiveradiatorvalves.
Check–replace.
Unevenheatdistributioninbuilding
becauseofincorrectlysetbalancingvalves,
orbecausetherearenobalancingvalves.
Adjust/installbalancingvalves.
Diameterofpipetosubstationtoosmallor
branchpipetoolong.
Checkpipedimensions.
Unevenheatdistribution.Airpocketsinthesystem.Venttheinstallationthoroughly.
DHsupplytemperaturetoohigh.
Wrongsettingofthermostatorof
automaticcontrols,ifany.
Adjustautomaticcontrols,–see
instructionsforautomaticcontrols.
Defectivecontroller.Thecontrollerdoes
notreactasitshouldaccordingtothe
instructions.
Callautomaticcontrolsmanufactureror
replacetheregulator.
Defectivesensoronself-actingthermostat.
Replacethermostat–orsensoronly.
DHsupplytemperaturetoolow.
Wrongsettingofautomaticcontrols,ifany.
Adjustautomaticcontrols–seeinstructions
forautomaticcontrols.
Defectivecontroller.Thecontrollerdoes
notreactasitshouldaccordingtothe
instructions.
Callinautomaticcontrolsmanufactureror
replacecontroller.
Defectivesensoronself-actingthermostat.
Replacethermostat–orsensoronly.
Wrongplacement/ttingofoutdoor
temperaturesensor.
Adjustlocationofoutdoortemperature
sensor.
Strainerclogged.Cleangate/strainer.
DanfossHeating
VI.GP .W4.02/LUK40250
DEN-GT
17
OperatingGuideTermixVMTD-FMIX-I
ToohighDHreturntemperature.
Toosmallheatingsurface/toosmall
radiatorscomparedtothetotalheating
requirementofthebuilding.
Increasetotalheatingsurface.
Poorutilizationofexistingheatingsurface.
Defectivesensoronself-actingthermostat.
Makesuretheheatisdistributedevenly
acrossthefullheatingsurface–openall
radiatorsandkeeptheradiatorsinthe
systemfromheatingupatthebottom.It
isextremelyimportanttokeepthesupply
temperaturetotheradiatorsaslowas
possible,whilemaintainingareasonable
levelofcomfort.
Thesystemissinglepipeloop.
Thesystemshouldfeatureelectronic
controlsaswellasreturnsensors.
Pumppressuretoohigh.Adjustpumptoalowerlevel.
Airinsystem.
Ventthesystem.
Defectiveorincorrectlysetradiator
valve(s).Singlepipeloopsystemsrequire
specialone-piperadiatorvalves.
Check–set/replace.
Dirtinthemotorizedvalveorinthe
differentialpressurecontroller.
Check–cleanout.
Defectivemotorizedvalve,sensoror
automaticcontroller.
Check–replace.
Electroniccontrollernotadjustedcorrectly.Adjustaccordingtoinstructions.
Noiseinsystem.
Pumppressuretoohigh.Adjustpumptoalowerlevel.
Heatloadtoohigh.
Defectivemotorizedvalve,sensoror
electroniccontroller.
Check–replace.
7.4Disposal
Disposal
Thisproductshouldbedismantledanditscomponents
sorted,ifpossible,invariousgroupsbeforerecycling
ordisposal.
Alwaysfollowthelocaldisposalregulations.
18
DEN-GT
VI.GP .W4.02/LUK40250
DanfossHeating
OperatingGuideTermixVMTD-FMIX-I
8.0Declaration
8.1Declarationofconformity
Category0withelectricalequipment
DanfossHeating
VI.GP .W4.02/LUK40250
DEN-GT
19
OperatingGuideTermixVMTD-FMIX-I
ProducedbyDanfossA/S©12/2016
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