EngA DJM3 Mounting instructions

IOM‐17WWW.ENGINEEREDAIR.COMMAR99R3
USER OPERATION
MANUAL
FOR
DJM3
INDIRECT FIRED HEATING CONTROLLER
UNIT MODEL NO. _________________
UNIT SERIAL NO. _________________
SERVICED BY: ___________________
TEL. NO: ________________________
CANADIAN
HEAD OFFICE
AND FACTORY
USA
HEAD OFFICE
AND FACTORY
CANADIAN
EASTERN FACTORY
1401 HASTINGS CRES.
SE
CALGARY, ALBERTA
T2G 4C8
Ph: [phone]
Fax: [phone]
32050 W. 83r
d
STREET
DESOTO, KANSAS
66018
Ph: [phone]
Fax: [phone]
1175 TWINNEY DRIVE
NEWMARKET,
ONTARIO
L3Y 5V7
Ph: [phone]
Fax: [phone]
SALES OFFICES ACROSS CANADA AND USA
Retain instructions with unit and maintain in a legible condition.
Please give model number and serial number when contacting
factory for information and/or parts.


A DJM3
IOM-17 2 of 27 Mar 99 R3

DJM3


TheDJM3hasbeencertifiedbyIntertek(ETL)forusewithEngineeredAirappliancesonly.Ithasbeen
evaluatedtoCSAC22.2No.24Temperature‐IndicatingandRegulatingEquipmentandUL873UL
StandardforSafetyTemperature‐IndicatingandRegulatingEquipment.ThisisaUserOperation
Manualandthereforenotsubjecttoevaluation.

IfanyerrorsoromissionsarenotedpleasecontactthenearestEngineeredAirTechnicalService
Department.

Toensurewarrantyishonored,onlyqualifiedpersonnelshouldbeemployedforserviceand
troubleshooting.IffurtherinformationisrequiredpleasecontactthenearestEngineeredAiroffice.

Therearetwosetsofelectricaldrawingsandunitfunctionsheetsprovidedwiththeappliance.Oneset
isinanenvelopewhichalsocontainstheOperation,InstallationandMaintenancemanual(s).This
packageisforcopying,thenshouldeitherbereturnedtotheapplianceorstoredinasafeplace.The
othersetisattachedtothecontrolpaneldoorandshouldneverberemoved.

Pleasereportanyomissionstothenationalservicemanager.

Warning:

Improperinstallation,adjustment,alteration,serviceormaintenancecancause
propertydamage,injuryordeath.Readtheinstallation,operatingand
maintenanceinstructionsthoroughlybeforeinstallingorservicingthisequipment.

Warning: Thisunitisconnectedtohighvoltages.Electricalshockordeathcouldoccurif
instructionsarenotfollowed.Thisequipmentcontainsmovingpartsthatcanstart
unexpectedly.Injuryordeathcouldoccurifinstructionsarenotfollowed.All
workshouldbeperformedbyaqualifiedtechnician.Alwaysdisconnectandlock
outpowerbeforeservicing.DONOTbypassanyinterlockorsafetyswitchesunder
anycircumstances.





A DJM3
IOM-17 3 of 27 Mar 99 R3

A DJM3
IOM-17 4 of 27 Mar 99 R3
TABLEOFCONTENTS

INTRODUCTION...............................................................................................................................................................5
CONTROLLERRATINGS.....................................................................................................................................................5
CONTROLLERDESCRIPTION..............................................................................................................................................6
TERMINALS..................................................................................................................................................................................6
DIPSWITCHES..............................................................................................................................................................................7
INDICATIONANDDIAGNOSTICLIGHTS........................................................................................................................................7
ADJUSTMENTPOTS......................................................................................................................................................................8
MULTIMETERTESTPOINTS..........................................................................................................................................................9
SYSTEMTIMINGS.........................................................................................................................................................................9
TEMPERATURECONTROL.................................................................................................................................................9
CALCULATEDSETPOINT(SPC)......................................................................................................................................................9
DISCHARGETEMPERATURESENSOR(DTEMP)..........................................................................................................................10
MODULATINGROOMRESET......................................................................................................................................................10
MultipleRoomSensors....................................................................................................................................................11
ROOMRESETAUTHORITYTABLE...............................................................................................................................................11
BMSRESET.................................................................................................................................................................................12
AMBIENTRESET(CONTINUOUSBLOWEROPERATIONONLY).................................................................................................................12
MAKE/BREAKRESETANDOVERRIDE...........................................................................................................................................13
“OR”and“V”Override(DayOperationonly)..................................................................................................................13
“X”and“Z”Override(DayandNightOperation).............................................................................................................13
OPERATION...................................................................................................................................................................14
DAY/NIGHTOPERATION...........................................................................................................................................................14
FANCONTROL............................................................................................................................................................................14
DAMPERCONTROL....................................................................................................................................................................14
BURNERCONTROL.....................................................................................................................................................................14
LOWLIMIT..................................................................................................................................................................................15
ResettingLowLimit..........................................................................................................................................................15
SERVICE.........................................................................................................................................................................15
SERVICEMODE...........................................................................................................................................................................15
BURNERSETUP..........................................................................................................................................................................15
TEMPERATURECONTROL..........................................................................................................................................................22
AIRBALANCING..........................................................................................................................................................................22
PRE‐PURGEPROBLEM................................................................................................................................................................22
INDUCEDVOLTAGEONREMOTECONTROLWIRING..................................................................................................................23
CALIBRATION.................................................................................................................................................................23
DISCHARGESENSOR........................................................................................................................................................................23
DISCHARGESETPOINTCALIBRATION...................................................................................................................................................23
ROOMSENSORCALIBRATION............................................................................................................................................................23
BMSSIGNALCALIBRATION...............................................................................................................................................................24
SENSORTABLE...........................................................................................................................................................................24
FANOPERATIONFLOWCHART........................................................................................................................................25
HEATOPERATIONFLOWCHART......................................................................................................................................26
UPGRADINGDJM3.2OR3.3TODJM3.4.........................................................................................................................26

A DJM3
IOM-17 5 of 27 Mar 99 R3
INTRODUCTION

TheDJM3isanindependentcontrollerforEngineeredAirDJstylegasfiredheatingequipment
designedtoprovidethemajorityofcontrolrequirements.TheDJM3modulatesavariablespeed
combustionblowerinconjunctionwithanmodulatinggasvalve.Thecombustionblowerspeedand
thegasvalveflowratearebothmodulatedtomaintaintherequireddischargeairtemperature.

Theinformationusedinthismanualshouldbeusedinconjunctionwiththeunitfunctionsheet(s)and
theDJ(E,S)&DGorDJXseriesInstallation,Operation,andMaintenancemanuals.

TheDJM3isdesignedtocontrolonlyEngineeredAirequipment.Variousupgradesandimprovements
havebeenmadeovertime.Alwaysincludeanysuffixlettersandnumbersfortroubleshootingand/or
replacement.

Note:Itisnecessarythatalloftheremotewiringandcontrolsbecompleteandoperationalbefore
startingtheappliance.

CONTROLLERRATINGS

Powerrequirements:24Vac,40VA.
ContactRating:120V5Ainductive
0‐10Vdcinputimpedance:2k
Environment:‐40to120°F(‐40to50°C)non‐condensing.
FuseRating:1.5GDCslow‐blow


A DJM3
IOM-17 6 of 27 Mar 99 R3
CONTROLLERDESCRIPTION

TERMINALS
TABLE1
Terminal Description
T1 Boardpowersupply.(HOT)24Vacisolated.
T2 Boardpowersupply.(NEUTRAL)24Vacisolated.
FS Fanswitch(orDaymode)enableinput(24Vac).
K Night(unoccupied)modeenableinput(24Vac).
HS Heatenableinput(24Vac).
N Grounded24Vacneutral(referencetoFS,K,HS).
DM1,DM2 Dampermotoroutputcontacts(dry).
FR,CFR Flamerelayoutputcontacts(dry).
AL Alarmoutput.
C Contactcommoninputpower(toALandSA).
SA Supplyairfanenableoutput.
CB1 Combustionblowermotorinput.
CB2 Combustionblowermotorspeedcontroloutput.
PV1,PV2 Pilotvalvedisablecontact(dry).
VFB120 Maingasvalvefeedback(SSOV)hotinputfor120Vvalves.
VFB24 Maingasvalvefeedback(SSOV)hotinputfor24Vvalves.
VN Maingasvalvefeedback(SSOV)neutralinput.
MX1,MX2 Modulatingvalveoutput.(DCvolts)
VS Legacyinput.Notused.
OS,GS,YS Combustionblowerspeedsensorinput.
Q,U Dischargeairtemperaturesensorinput.
SSPM Internal(jumpered)orexternaldischargesetpointinputs.
VXYZ Modulating(resistive)room/returnairthermostatinputs.
OR Singlestageheatthermostatinput.
+/‐ 0‐10Vdc(4‐20mA)temperatureresetinput.



A DJM3
IOM-17 7 of 27 Mar 99 R3
DIPSWITCHES
TheDJM3optionsareconfiguredbyDIPswitchselectionand/orwiringconnections.
TABLE2
DIPSW Description
1 EnableVdcormAtemperatureresetifON.
2 EnableambientresetifON.
3 Enableroom/returntemperatureresetifON.
4 Notused.
5 Servicemode(mustbeleftOFFfornormaloperation).
6 Notused.
7 ConstantcombustionairpurgemodeifON.
8 EnablelowlimitdischargetemperaturesensingifON

Note:TheDJM3willonlyacceptonetypetemperatureresetsignal.

INDICATIONANDDIAGNOSTICLIGHTS
Thereare4statuslightsontheDJM3labeled1to4.Theyoperatein4patterns:constanton,2second
flash(onfor1second,offfor1second),1secondflash(onfor½second,offfor½second)andan
irregularflash(flashestwice,thenoff,repeat).
TABLE3
LIGHT LEDON 2SECFLASH 1SECFLASH INTFLASH
1 LLLOCKOUT LLBYPASS DSENOPEN ‐‐‐‐‐‐‐‐‐‐
2 PREPURGE PPPROBLEM ‐‐‐‐‐‐‐‐‐‐ ‐‐‐‐‐‐‐‐‐‐
3 HEATCALL HTSWOPEN ‐‐‐‐‐‐‐‐‐‐ SERVICEMODE
4 IGNENABLE ‐‐‐‐‐‐‐‐‐‐ FLAMEFAIL ‐‐‐‐‐‐‐‐‐‐


1 ON
Theappliancehasbeenshutdownduetolowlimitfailureandlockout.
(dischargetemperaturebelow4°C(40°F))Resetwiththeserviceswitch.
Normaloperatingstatus:OFF.
1 2SEC
Unithaslowdischargetemperatureandistimingout.Ifthetemperaturedoes
notrecovertoabove4°C(40°F)itwillshutdownandlockout.
Normaloperatingstatus:OFF,orwaitingforthedischargetemperaturetorise
above4°C(40°F).
1 1SEC
Thedischargesensorcircuitisopen(sensorrangemustbebetween880and
4000Ω).
Normaloperatingstatus:OFF.
2 ON
Thecombustionblowerispurgingtheexchangerasapreliminarytoignition.
Normaloperatingstatus:EITHERONorOFF.
2 2SEC
PrePurgeproblem.TheDJM3isnotreceivingacorrectsignalfromthehall
effecttachometersensor,intoterminalsYS,OS,GS.
Normaloperatingstatus:OFF.

A DJM3
IOM-17 8 of 27 Mar 99 R3
3 ON
Thedischargesensorisbelowcalculatedsetpoint(SPC)andtheDJM3has
initiatedtheheatingsequence.
Normaloperatingstatus:ONforheating.
3 2SEC
Thereisacallforheating,howevertheheatinghasbeendisabledfromno
inputintoterminalHS(24Vac).
Normaloperatingstatus:OFF.
3 INT
FLASH
Unitisinservicemode,allowingthetechniciantomanuallysettheheating
fromlowtohighfirewiththeservicepot.
Normaloperatingstatus:OFF.
4 ON
FRandCFRcontactshaveclosed,enablingtheignitioncontroltofirethe
burner.
Normaloperatingstatus:ONforheating.
4 1SEC
Burnerignitionwasunsuccessful.TheDJM3didnotreceiveamaingasvalve
(SSOV)feedbacksignalintoterminalsVFB24orVFB120.
Normaloperatingstatus:OFF.


ADJUSTMENTPOTS
Thereareanumberofsettingandcalibrationpotentiometers(POT’s)locatedonthefrontofthe
DJM3.Modificationstotheseshouldonlybedonebyexperiencedandqualifiedpersonnel.
TABLE4
POT Description
DSENCAL Dischargesensorcalibration.
DISSPCAL Dischargesetpointcalibration.
BMSCAL BMS(0‐10Vdcor4‐20mA)resetcalibration.
ROOMCAL Roomsensorcalibration.
SERVICE Servicemodepot.
RESETRATIO Temperatureresetrangeadjustment.
LOWFIRE* LowfirespeedRPMadjustmentpot(nearterminalPV1).
CURVEMATCHING* ValvecurvematchingRPMadjustmentpot(nearterminalCS).
SETPOINT Ifused,theon‐boarddischargesetpointdial.
*Thesepotsshouldonlybeadjustedwhenusedwithacombustionanalyzer.




A DJM3
IOM-17 9 of 27 Mar 99 R3
MULTIMETERTESTPOINTS
TheDJM3hasreadoutterminalsformeasuringthedischargesensortemperatureandthecalculated
dischargesetpoint.These3testpointsarelocatedneartheMandQterminals.

MeasurementsaremadeusingaVdcmultimeterusingascaleof1Vdc=10°C.Forexample,areading
of2.1Vdc=21°C(or70°F).RefertothetablebelowforCelsiustoFahrenheitconversion.

TABLE5
VoltageReading(Vdc) °C °F
1.0 10 50
1.5 15 59
2.0 20 68
2.5 25 77
3.0 30 86
3.5 35 95
4.0 40 104



SYSTEMTIMINGS
Thetimeslistedaregeneral,andmaybeaffectedbyexternaltimedelaydevices.
TABLE6
Pre‐purge 45seconds
Postpurge 4minutes(daymode)1minute(nightmode)
Fandelay 30seconds
Warmuptime 30seconds
Cooldowntime 60seconds
Lowlimitbypass 5minutes
FlameFailure 90seconds

TEMPERATURECONTROL

CALCULATEDSETPOINT(SPC)
TheDJM3isdesignedtobeadischargeairtemperaturecontrol.Thebasedischargeairtemperature
setpointistypicallysetfromthecontrolpotlocatedonthefaceoftheDJM3.Thebasedischargeair
temperatureisnormallymodifiedfromaremotesignaltomaintainthedesiredtemperatureofthe
suppliedspace.Thisiscalledreset.TheDJM3dischargesetpointcanberesetfromavarietyofsources
suchasambientairtemperature,modulatingorstagedroomthermostats,returnairtemperature,ora
BMSsignal(0‐10Vdcor4‐20mA).
Withoutanytemperatureresetmethodthebasesetpoint(eitherfacemountedorremotemounted)is
thecalculatedsetpointthattheDJM3willattempttomaintainthedischargetemperatureat.

SetpointCalculation(SPC)=DischargeSetpoint+Reset


A DJM3
IOM-17 10 of 27 Mar 99 R3
TheDJM3isdesignedtouseeitherofthefollowingasasetpoint:
 ThesetpointmountedonthefaceoftheDJM3(rangeof50‐95°F(10‐35°C)).IftheDJM3face
mountedset‐pointisused,terminals“SPandS”mustbejumpered;or
 TheJohnsonControlsTE6100‐960set‐point(rangeof50‐85°F(10‐29°C)).IftheTE6100‐960isused
asaset‐point,“StoSP”isnotjumperedandtheTE6100mustbewired:

TABLE7
TE6100Wires DJM3Terminals
Violet(notused) ‐
Red(notused) ‐
Grey WiredtoterminalU
Blue WiredtoterminalM
Orange WiredtoterminalS

DISCHARGETEMPERATURESENSOR(DTEMP)
TheDJM3usesthedischargesensorforbothtemperaturecontrolandlowlimit.Becauseofthis,the
DJM3willnotoperatewithafaultydischargesensor.Ifthedischargesensorresistanceisgreaterthan
4000‐ohmsorlessthan880‐ohms,theunitwilllockouteitheronlowlimitorbadtemperaturesensor.

MODULATINGROOMRESET(continuousbloweroperationonly)
DIPswitch3mustbe"on".ThisoptionalsorequiresaTE6100wired:
TABLE8
TE6100Wires DJM3Terminals
Red(notused) ‐
GREY WiredtoterminalV
VIOLET WiredtoterminalX
ORANGE WiredtoterminalY
BLUE WiredtoterminalZ

IfDIPswitch3isonandtheTE6100isnotwiredtothecorrectDJM3terminals,theDJM3willresetthe
dischargetemperaturedownasitthinksthattheroomsensorisverywarm.Theroomtemperature
requirementscanincreaseordecrease(reset)thecalculateddischargeairset‐point.

Note:Ifroomresetcalling,the“calculated”dischargetemperaturesetpointwillvaryfromthesetting
of“master”setpoint.
 Theroom‐resetfeatureisactivatedbyDIPswitch3.
 RoomsensorcalibrationpotisRoomCalPot.
 Roomresetbandis3°F(fixed).


The“roomresetband”meansaroomtemperatureerrorofjust3°Fwillresultinamaximumresetof
thedischargeairsetpoint.Theactualamountreset(indegrees)variesasperboththesettingofPot
ResetRatioandthedischargesetpoint.Thecalculateddischargeairsetpoint(dialsetting+reset)is
limitedbetween48and120°F.


A DJM3
IOM-17 11 of 27 Mar 99 R3
TodeterminetheamountofresetavailablerefertoTable9.

EXAMPLE:DJM3setpoint70°F;pot#5setat3;roomthermostatset75°F.
 Ifroomthermostatsensorisat75°F‐noreset,dischargeat70°F.
 Ifroomsensoris3°Fcold(72°F),dischargeisresetupfullamountofitsauthority(+20)to90°F.
Ifroomthermostatwasat73°Fthenoftheresetwouldbeused(*20isapprox.14°F),
addedontotheset‐pointof70°Fgivingdischargeof84°F.
 Ifroomsensoris3°Fhot(78°F)fullresetdownwilllowerthedischarge13°(57°Fdischarge).
MultipleRoomSensors
FoursensorscanbewiredtogiveanaveragereadingofroomtemperaturestotheDJM3control.They
mustbewiredinaseries/parallelarrangement.Refertomainorfieldelectricaldiagramfor
appropriatewiring.

ROOMRESETAUTHORITYTABLE
TABLE9
Discharge
Set‐Point
Reset
Ratio
Pot
Maximum
Temp.°C
Minimum
Temp.°C
Reset
Band
Width
°C
Maximum
Temp.°F
Minimum
Temp.°F
Reset
Band
Width
°F
15.5°C

60°F
1 25(+9.5) 12(‐3.5) 13 77(+17) 54(‐6) 23
2 26(+10.5) 11.5(‐4) 14.5 79(+19) 53(‐7) 26
3 28(+12.5) 10.5(‐5) 17.5 82(+22) 51(‐9) 31
4 33(+17.5) 9(‐6.5) 24 91(+31) 48(‐12) 43
5 38(+22.5) 9(‐6.5) 29 100(+40) 48(‐12) 52
21°C

70°F
1 29(+8) 16(‐5) 13 84(+14) 61(‐9) 23
2 30(+9) 15(‐6) 15 86(+16) 59(‐11) 27
3 32(+11) 14(‐7) 18 90(+20) 57(‐13) 33
4 37(+16) 11(‐10) 26 99(+29) 52(‐18) 47
5 40.5(+19) 9(‐12) 31.5 105(+35) 48(‐22) 57
27°C

80°F
1 33(+6) 21(‐6) 12 91(+11) 70(‐10) 21
2 34(+7) 19(‐8) 15 93(+13) 66(‐14) 27
3 35.5(+8) 18(‐9) 17.5 96(+16) 64(‐16) 32
4 39(+12) 15(‐12) 24 103(+23) 59(‐21) 44
5 44(+17) 11(‐16) 33 111(+31) 52(‐28) 59
32°C

90°F
1 38(+6) 25(‐7) 13 100(+10) 77(‐13) 23
2 38(+6) 23(‐9) 15 101(+11) 74(‐16) 27
3 40(+8) 22(‐10) 18 104(+14) 72(‐18) 32
4 44(+12) 18(‐14) 26 111(+21) 64(‐26) 47
5 47(+15) 13(‐19) 34 116(+26) 56(‐34) 60

NOTE: Theabovetableisnotlinearandresetupanddownisequalataset‐pointofabout82°F


A DJM3
IOM-17 12 of 27 Mar 99 R3
BMSRESET(continuousbloweroperationonly)
DIPswitchonemustbeontoactivateBMSreset.Thisoptionrequiresananalogvoltageorcurrent
signaltobewiredtotheopticallyisolated+and‐terminals.Theanaloginputsignalproportionally
increasesthecalculateddischargeairset‐point.Thecalculateddischargeset‐pointequalsthedial
dischargeset‐pointplustheinputsignalmultipliedbyaresetratiofactor.

Themaximumamountofresetisadjustablefrom15°F(8°C)to60°F(33°C).Themaximumdischarge
temperature(dialset‐pointplusreset)islimitedto120°F(49°C).TheBMSresetoptionisactivatedby
DIPswitch1.

Note: Asstandard,theDJM3isdesignedtooperatewith4‐20mAor2‐10Vdcintoa500‐ohminput
impedance.SomeBMSdevicesmaynothaveenoughpower(Volt‐Amps)toprovideafull10
VDCwhenconnectedtoa500‐ohmload.Theinputresistanceforthisoperationcanbe
increasedto1500ohmsbycuttingresistorR43.Tocutthisresistoryoumustturntheboard
over.Itislocatedonthebackofthelargerboard,justbelowtheDIPswitchblockandbeside
PotResetRatio.Thisisa1‐watt,680‐ohmresistorcoloursblue,grey,brown,gold.

BMSresetisnottrulylinear.Resetwillusuallybeginatabout4volts.Following,isanexampleofreset
fromoneapplicationthatgivesa13°Cor24°Freset.

CALCULATEDSETPOINTFROMBMSRESETAPPLIEDTO+AND–
TABLE10
Current
Reset
Voltage
Reset
CalculatedSetpoint

mA Vdc °C °F
‐ 0 13 55
3 3 13.5 56
5 4 14.5 58
12 6 16 61
‐ 7 18 65
16 8 20 68
‐ 9 23 75
20 10 26 79

AMBIENTRESET(continuousbloweroperationonly)
ThisoptionrequiresDIPswitch2tobeonandanambientsensor(JohnsonControlsTE6000‐960)
wiredtoterminalsXandZ.Thedischargeairset‐pointwillberesetupwardsbasedontheambient
temperature.Ambienttemperaturesbelow70°F(21°C)willgraduallyincreasethecalculateddischarge
airset‐point.Themaximumincreaseinthedischargetemperaturewillbereachedwhentheambient
fallsto20°F(‐7°C).TheamountofresetisdependentonthepositionofResetRatioPotandthe
dischargeset‐pointassetonthedial.
(Thedischargeset‐pointwillberesetbelowmasterset‐pointifambientisabove70°F(21°C).Inmost
caseswhentheoutsideambientisabove70°F(21°C),theheatwillbeoff.)


A DJM3
IOM-17 13 of 27 Mar 99 R3
Itispossibletoobtainanextendedtemperaturerangebyplacinga120‐ohmresistorinserieswiththe
ambienttemperaturesensor.

Note: Withthisresistorthedischargetemperaturewillbeatitsmaximumwhenambientisat‐15°F.
Withthisresistor,thecalculateddischargeairset‐pointequalsthedialset‐pointat35°F
(differentfromabove).Above40°Fthecalculateddischargeairtemperaturewillbebelowthe
dialset‐point.
TABLE11
ResetRatioPot
Setting
ResetAmount°F
(noresistor)
ResetAmount°F
(witha120ohmresistorinseries)
1 10 18
2 11 20
3 13 24
4 16 30
5 21 37

MAKE/BREAKRESETandOVERRIDE
“OR”and“V”Override(DayOperationonly)
ToactivatethisfeatureDIPswitch3mustbeoff.Ifathermostatorcontactisclosedacrossterminals
“OR”and“V”,thedischargetemperatureissetat120°F(49°C).Whenthermostatorcontactisopen,
thedischargetemperatureissetatthedialsetpointplusanyotherresetsbeingused.
“X”and“Z”Override(DayandNightOperation)
ToactivatethisfeatureDIPswitch3mustbeon.Duringdayoperation,ifathermostatorcontactis
closedacrossterminals“X”and“Z”,thedischargetemperatureissetatthedialsetpointplusthe
maximumamountofresetupwards.Whenthethermostatorcontactisopenacrossterminals“X”and
“Z”,thedischargetemperatureissetatthedialsetpointlessthemaximumamountofreset
downwards.

DuringNightoperation,ifathermostatorcontactisclosedacrossterminals“X”and“Z”,thedischarge
temperatureissetat120°F(49°C).Whenthethermostatorcontactisopenacrossterminals“X”and
“Z”,heatisoff.








A DJM3
IOM-17 14 of 27 Mar 99 R3
OPERATION

DAY/NIGHTOPERATION
TheDJM3supportsavarietyoffan,damper,andtemperaturecontroloperatingschemes.Theexact
operationdependsonthestatusofterminals“FS,HS”,and“K”.Nightoperationisnotsuitablefor
100%make‐upairapplications,duetotheequipmenthavingtoopenoutsideairdampersandheat
outsideair.TooperateinNightmode,aroomthermostatormake/breakresetmustbeused.
TABLE12
TerminalStatus Blower
Operation
Damper
Operation ControlSource Control Mode
HS FS K
XXX
XXX
Off
On
Off
Off
Off
Constant
Off
Powered
N/A
Discharge/Room/BMS
Off
Day
Off
On
On
XXX
Off
On
On
On
On
Off
Intermittent
Constant
Off
Off
Off
N/A
Room
Dischargew/Room
Reset
Off
Night
Night
XXX=Switch(SW.)canbe"ON"or"OFF"

FANCONTROL
Indaymode,thesupplyairfanshouldruncontinuously(unlessjuststartingthemorningwarm‐upor
trippedonlowlimit.).Forsupplyfanoperation,thedischargesensormustbeoperatingcorrectlyasit
isalsousedasthelowlimitsensor.Ifthedischargesensorresistanceistoohigh(oropencircuit),the
DJM3perceivesalowlimitfaultandlocksoffDJM3.

DAMPERCONTROL
Theinletdamperactuator(s)isenabledthroughoutputterminalDM2.TheDJM3hasadelayedsupply
blowerstarttoallowtimeforthedamperstoopen.

BURNERCONTROL
Burnerisenabledwhenavalidheatcallismadeandterminal“HS”ispowered.TheDJM3willentera
heatexchangerpurgecycle.Whenthepurgecycleiscomplete,theDJM3willruncombustionblower
atlight‐offspeedandenabletheignitioncontroltostartthepilot.Whentheignitioncontrolproves
pilotlight‐offitwillenablethemaingasvalve.OncethemainflameisestablishedandtheDJM3
receivesafeedbacksignaltoterminalsVFB24orVFB120andVNthecontrolwillmodulatethegas
valveandcombustionblowertosatisfytheheatcall.IftheDJM3doesnotreceivethefeedbacksignal
thealarmcontact,terminal“AL”,willbeactivated.

WhenheatcallissatisfiedtheDJM3willcycleofftheburner.Thecombustionblowerwillcontinueto
runforseveralminutesafterheatcallisopentomaintainpurgeandcoolofftheburnerandheat
exchanger.


A DJM3
IOM-17 15 of 27 Mar 99 R3
LOWLIMIT
Thelowlimitsetpointisfixedat40°F.Therearetwolowlimitbypasstimers,start‐upandanti‐noise.
Thestart‐upautobypasslowlimittimerisstartedeverytimeterminal“K”,“SA”or“FS”energized
statuschanges(on/off).Thestart‐uptimerwillbypassthelowlimitfor5minutes.Afterthe5minute
startupbypass,a30‐secondanti‐noiselowlimitbypasstimerisstartedeverytimealowlimit
conditionisdetected.Thistimerisdesignedtopreventnuisancetripscausedbyanyelectricalnoise
pickedupbythedischargesensor.Ifthelowlimitconditionexistsformorethan30seconds,alow
limitlockoutwilloccur.ThiswillactivatethealarmcontactontheDJM3,terminal“AL”.
ResettingLowLimit
Toresetthelowlimit,cyclepowertotheDJM3controlterminals"T1"and/or"T2";orinterruptpower
toterminals"FS,HS,andK"allatthesametime.

SERVICE

SERVICEMODE
PlacingtheDJM3intoservicemodeallowsfordirectcontroloftheburnerfiringrate.DIPswitch5will
activateservicemodeandenabletheheatimmediately.TheservicePOT,locatedtotherightofthe
setpointdial,willmanuallysettheburnertoanyfiringrate.Wheninservicemode,thesupplyairfan
mayneedtobeactivatedmanually.

Note:DONOTleaveDJM3inservicemode,burnerwillnotcycleoff.Servicemodeshouldonlybeused
forcombustionset‐upandoperationalchecks.

BURNERSETUP
ServicePot
Thispotisdesignedtoallowaservicetechniciantomanuallysettheburnertoanyfiringratehe
chooses.Iftheserviceswitch(dipswitch5)isonandtheblowerswitch(terminalFS)ispowered,the
burnerfiringrateiscontrolledbytheServicePot.TheServicePotislocatedclosetothe“+"terminal
andabovethedipswitches.Rotatingthispotwillallowthefiringratetobesetatanyratebetweenlow
andhighfire.
LowFirePot
ThelowfirepotislocatedbelowthePV1terminal.Thelowfirepotisusedtoadjustthecombustionair
atlowfire.Thelowfirespeedisadjustablefrom1150to1400RPM(highturndown)or1800to2000
(standardburner).Thelowfirepotistobeadjustedbyaqualifiedservicetechnicianonly.
CurveMatchingPot
ThecurvematchingpotislocatedbelowtheCSterminal.TheDJM3canbeusedwithseveraldifferent
Maxitrolvalves.Eachofthesevalveshasaslightlydifferentopeningcurve.TheCurveMatchingPotis
tobeadjustedbyaqualifiedservicetechnicianonly.

A DJM3
IOM-17 16 of 27 Mar 99 R3
BurnerSelection
TheDJM3isdesignedtooperatewithboththestandard(roundburnerplate)andhighturndown
(rectangular)burners.TheselectionismadebycuttingajumperwireR100whichislocatedonthe
smallboard.(TheDJM3mustbeturnedovertoaccessthejumperwire.)

NOTE: JumperwireR100iscutonlyforthehighturndownburneroperation.Caution–donotcut
resistorR100onthelargeboard.
NOTE: Donotadjustanyotherpotslocatedonthesmallboard,whicharenotaccessiblefromthe
frontoftheDJM3

CombustionSetUp
Whenmeasuringcombustiongases,ensureprobeofanalyserinsertsfullyintotheflueconnectionto
theheatexchanger.Measuringattheflueoutletmaybeadilutedreadingduetoairmixingintothe
flue.

NOTE: Ifcombustionisnotsetcorrectlyitcanresultimproperburningwhichmayproduce
productsofcombustionthatsmell,carbonandoranexcessiveamountofwaterintheflue.
Careshouldbetakentosetburnersupproperly.Notethattemperatureoftheairandfuel
mayhaveagreataffectonthesetupselected.Ifboththecombustionairandthefuelare
ataconstanttemperaturethroughouttheheatingseason,oncecombustionissetitshould
remainsimilarthroughtheseason.

HighTurndown(Rectangular)Burner
MosthighturndownDJunitswillemployonofthefollowingMaxitrolmodulatingDCvoltgasvalves.

Series20 420,M520,M620.Thesevalvesdonothavehighfireregulators.Highfirepressureis
setupattheapplianceregulator.
Series50 550,M650,ES350.Thesevalvesdonothavehighfireregulators.Highfirepressureis
setupattheapplianceregulator
ES345D‐L Thisvalvehasabuiltinhighfireregulator.TypicallyusedonDJ140models.

Theabovevalvesdifferfromeachotherinsize,configuration,BTUcapacity,physicallayout,andlow
firesetup.
Check the equipment to verify what type of modulating gas valve you have to ensure the correct
combustionsetupmethodisused.


A DJM3
IOM-17 17 of 27 Mar 99 R3
HighFireSetUp
1. Turnontheserviceswitch(dipswitch5).
2. SettheServicePottohighfire.Adjustthehighfireinputtothecorrectclockedrate.Adjust
combustionairsliderorinletdamperuntilthehighfireO2readingisbetween3.5and4.2%.

LowFireSetUp
Ensurethatthereisaluminiumtubingconnectedfromthetopofthemodulatinggasvalvevent
connectiontotheburnerbox.Thisistoguaranteethatthevaryingburnerboxairpressureallowsthe
propergasflowratethroughthemodulatinggasvalve.Alsoensurethatthesmallventholeunderthe
ovalshapedcoverissealedoffwithsiliconeorTremcotape.Whendoingcombustionanalysisitis
importantthatthetopofthevalvebesealedbyeitherreinstallingthecapaftereachadjustment,or
placingyourfingerfullyoverthetoptosealtheopentoponthevalve.Thereasonforthisrequirement
isthatthevalveis“toploaded”whichmeansthatthevalveishavingpressurefromthecombustionfan
addedtothetopofthevalve’sdiaphragmthusincreasingthegasflowthroughthevalve,especiallyat
higherflow.

Series20/M420,M520andM620(HighTurndownBurner)
Thesevalveshave2lowfireadjustmentsthefollowingprocedureshouldbefollowedcarefully.
Oncethehighfirepressureandcombustionhasbeensetup,turntheServicePotfullycounter‐
clockwisetoachievelowfire.AdjusttheLowFirePotuntilthelowfirespeedonthecombustionfan
motoris1250RPM±10RPM(20.8Hz)for10:1setupor1195RPM±5(19.91Hz)for15:1turndown.
AtthispointtheDCvoltagereadingatthemodulatinggasvalveterminalsshouldbe0VDC.
UnderthecoverontheMaxitrolseries20valveisanadjustmentscrew(brassorsilver)thathasalock
ringwhichusesaspecialtool(twoverysmallholes)toloosenit.

1. Thelockringneedstobeloosenedfirst.TurnitfullyCCW(up)nowturntheslotscrewin
thecentreofthelockring(springactivatedlowfireadjustment)fullCCW(up).
Caution:Donotovertorquethisscrewatthetoporbottomofitsadjustmentoritwill
breakthe“c‐clip”insidethevalve,thusallowingthespringtoridefree.
2. AdjustthelowfirebypassscrewatthebottomsideofthevalvebodyuntiltheO2readingis
between16.0%to16.5%.(16.5to17.5%oxygenfor15:1turndown.)Atthesesettingsthe
turndownwillbeverycloseto10:1.ThemaximumCOatlowfireis80PPM.
3. AdjusttheServicePotupveryslowlyuntiltheDCvoltsatthe modulating gas valve
terminalsareabout2.25VDC.Ifthevoltagerisesover2.25VDCwhileadjustingthemanual
pot,turnitdownandstartagainfromlessthan1.5VDCuntil2.25VDCisreached.
4. ChecktheO2readingagainatthispoint.IftheO2hasincreased,adjustthespringactivated
lowfireadjustmentontopofthevalveuntiltheO2readingissameasthelowfirereading
at0VDC.






A DJM3
IOM-17 18 of 27 Mar 99 R3
5. CurveMatchingProcedure
TurnServicePottohighfire(approximately3450RPMor57.5Hz)for1minute.Adjustthe
ServicePotdownveryslowlyuntilthecombustionmotorspeedisabout3060RPM(51Hz).
Ifthepotisadjustedbelow51Hzreturntohighfireandattempttolowerwithoutpassing
51Hz.Lettheburnerstabilizefor2minutes,thenre‐checkO2reading.IfO2hasdroppedto
lessthantheoriginalhighfireO2 reading, adjust the Curve Matching pot. Adjusting CCW
increasestheO2readingbyreducingthevoltagetotheMaxitrolmodulatinggasvalve.The
CurveMatchingpotonlychangesthevoltagetothegasvalve;itdoesnotaffectfanspeed.
IfthecurvematchingpotisadjustedtothefullyCCWpositionandtheO2readingisstillnot
within 10% of the original high fire O2 reading, add a 180‐ohm 2 watt resistor across the
modulatinggasvalveterminals;repeatabovetestuntilpropercurvematchingisachieved.
(A150‐ohm,2‐wattresistormayhavetobeusedifO2levelstilldoesnotrisetowithin10%
oforiginalhighfireO2reading.)
Switch burner to low fire again and re‐check low fire, both at 0 VDC and 2.25 VDC. (An
additionofaresistorabovemayhavechangedthelowfiresetting,ifitwasneeded.)
 Lockthelockingringonthespringactivatedlowfireadjustmentscrew(fromstep1).Failure
tolockitmaycausethescrewtovibratelooseallowinglowfire gaspressuretoincrease.
Thiscancreatesootingofburnerpartsandtheheatexchanger.Ifthelockingringismissing,
droponedropofLoctitethreadlockerontothebrassscrewthreads.

Series50/M550,M650ANDES350(HighTurndownBurner)
Thesevalveshaveonly1lowfireadjustment(springactivatedlowfire).
1. Thecombustionsetupissimilartotheaboveexceptthereisnolowfirebypassadjustment
onthebottomofthesevalves.Thereforesimplysetuplowfirebyturningthemanualfiring
PotResetRatiotothelowfireposition‐1250RPM10RPM20.8Hz.(15:1turndownsetat
1195RPM,19.91Hz.)Voltagetotheseries50valveshouldbenear0voltsDC.Adjustthe
springactivatedlowfireadjustmentatthetopofthemodulatinggasvalve(smallscrew)
untilanO2readingof16.8%to17.5%isachieved.
2. Lockthelowfireadjustmentscrewasdescribedinpoint7aboveandthenadjustthecurve
matchingpotasinpoint5above.

TypeES345D‐L(HighTurndownBurner)
Asthisvalvehas2lowfireadjustmentsthefollowingprocedureshouldbeapplied.
1. BringtheunittolowfireusingtheservicefiringpotfullyCCW.AdjustPotLowFireuntilthe
combustionfanisturning1250RPM10RPM(20.8Hz).(15:1turndownis1195RPM,19.91
Hz.)VoltagetotheESvalveshouldbenear0voltsDC.Thelowfirebypassadjustmenton
thisvalveisunderthetopcoveronthelargeportandtheadjustmentinsideitismarked:
IncreaseDecrease
Afterremovingthecover,loosenthelockingscrewfirstbefore making adjustment. This
shouldbedoneat0VDCtothemodulatinggasvalveterminalsandthespringactivatedlow
firebrassscrewturnedfullyCCWandthelockingringloosenedoff.


A DJM3
IOM-17 19 of 27 Mar 99 R3
2. Bringvoltagetogasvalveat2.25VDCandadjustthespringactivatedlowfireadjustment
located in the head with the electric modulator (smaller screw under cap) to achieve the
sameO2readingastheoneachievedat0VDC(16.8%to17.5%O2).Afterthisiscomplete
thenadjusttheCurveMatchingpotasdescribedinpoint5above.
PilotSetUp(HighTurndownBurner)
1. Onhighturndownunits,ensureairtubetopilotisfreeofdebrisandblockagesandthenset
pilotpressureto3.5"WC.
2. Pilotsetupisnotascriticalonthehighturndownburnerasthereisnotasmuchheatonit
asontheregularburner.
Standard(Round)Burner
MoststandardturndownDJunitswillemployoneofthefollowingMaxitrolmodulatingDCvoltgas
valves.
Series20M520,M620 Thesevalvesdonothavehighfireregulators.Highfire
pressureissetupattheapplianceregulator.Ifusedonthe
standardburner,thelowfireadjustmentlocatedonthe
bottomsideofthevalveistobeadjustedfullyclockwise
(nobypass).

Series50M550,M650,ES350 Thesevalvesdonothavehighfireregulators.Highfire
pressureissetupattheapplianceregulator.Thisseriesof
valvehasbeenreplacedwiththeM520/620series.

ES345D‐LThisvalvehasabuiltinhighfireregulator.

HighFireSetUp
1. Turnontheserviceswitch(dipswitch5).
2. SetmanualfiringPotHiService(locatednexttothe+terminal)tohighfire.Adjustthehigh
fireinputtothecorrectclockedrate.Adjustthecombustionairsliderorinletdamperuntil
thehighfireO2readingisbetween3.5and4.2%.

LowFireSetUp
Lowfireblowerinputis40%ofhighfireblowerinput.
Thelowfireproceduresetupissimilartothatforthehighturndownburnersnotedabove.The
differenceisthemaximumallowableCOatlowfireis200PPM.ThelowfireO2readingshould
bebetween10.9%to11.3%.Thecombustionsliderisdifferentthanthehighturndownslider.It
isaplatethatslidesbetweenthebloweroutletandtheburnerbox.ThelowfireRPMis
adjustedusingLowFirePotto185010RPM(30.5Hz).
Aftersettingupthelowfire,adjustthecurvematchingpotasdescribedinpoint5above.
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A DJM3
IOM-17 20 of 27 Mar 99 R3
PilotSetUp(StandardBurners)
Donotsetuppilotuntilyouareconfidenttheburnerisoperatingwithcorrectair/fuelmixture.
Ensurethepilottubeisfreeofdebrisand blockages.Onstandardroundburners,setpilotas
perthefollowingprocedure.
1. Installa10,000‐ohmresistorinserieswiththeflame
rodcircuit.
2. ConnectaDCvoltmeteracrosstheresistor.
3. Thereadingwillbeinmillivoltsifyourmeterdoes
notautoscale.
4. Connectamanometertothepilotline.
5. Runtheburneronmainflameforafewminutesto
havetheburnerplatewarm.
6. Leavethepilotonbutturnthemaingasoff.Youwill
havetojumpertheDJM3terminalsPV1andPV2to
dothisandremovethewirefromterminalVFB120orVFB24(dependingonvalvevoltage).
7. Aslowpilotgaspressurecandamagetheceramics,reducethepilotgaspressureto2.5
inchesandimmediatelyreturnittoahigherpressure.Thisistoensurethepilotgasregular
respondsproperly.
8. Adjustthepilotvalveregulatortoapressureinexcessof4.5inchespressure.
9. Slowlyreducethepilotgaspressurewhilewatchingboththepressureandthevoltmeter.
Themillivoltreadingshouldbeincreasing.Atthepointwhereitbeginstofallyoushould
stopreducingpressureandreturntothehighspot.

NOTE: Thefallinpressurecouldonlybeassmallasacoupleofmillivolts.Thispointshouldbe
between4.5and2.5inchespilotpressure.
NOTE: Somesmallerburners(DJ40250,000BTUHandsmaller),mayneedtohaveascrewplaced
throughthepilotairtubetoreducetheamountofairtothepilot.

10. Thisreadingisusedtodeterminetheadjustmentthatwillusuallygivethebestpilotlighting
andprovingstrength.However,caremustbetakentonotadjustthereadingforpilotgas
pressurebelow2.5incheswatercolumnpressureoryouwillbreakthepilotceramics.

11. Next,visuallyobservethepilotflame.Itshouldbevisibleataminimumof3oftheholes
aroundthepilot.Ifthepilotcannotbeseenthenitislikelyburningtoodeepintothepilot
box.Ifthisisoccurringcheckthatthegasketonthepilotassemblyisformingatightseal.
Alsoensurethattheburnerislocatedinthecenteroftheburnertube.Ifitismountedtoo
lowthentoomuchaircanflowoverthetopoftheburnerandaffectthepilot.







NOTE:Aftersetupiscompletemakesuretoturnoffdipswitch5.
Ignition
Control
10,000ohms
MVmeter
OK
Toolargeagap.Raise
burnerplateupto
centre.