EngA DJM3

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.)
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NOTE: JumperwireR100iscutonlyforthehighturndownburneroperation.Caution–donotcut
resistorR100onthelargeboard.
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NOTE: Donotadjustanyotherpotslocatedonthesmallboard,whicharenotaccessiblefromthe
frontoftheDJM3
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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.
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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.
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HighTurndown(Rectangular)Burner
MosthighturndownDJunitswillemployonofthefollowingMaxitrolmodulatingDCvoltgasvalves.
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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.
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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.
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