ICM Controls ICM291 Application Guide

7313 William Barry Blvd.
North Syracuse, NY 13212
ICM CONTROLS 800.365.5525
www.icmcontrols.com
LIAF098
FEATURES
• DirectSparkIgnition(DSI)controlboard
• Microprocessor-based
• Controlscombustion,blowerandindoormotors;sparkignitor;andthegasvalve
• Monitorstiming,trialforignition,amesensingandlockout
• 100%lockoutsafetyfeature
• CompatiblewithLPorNaturalGas
• StatusLEDforfaultcodestoaidintroubleshooting
• Replaces:CarrierLH33WP003A
Install New Control
1. Groundyourself.Whenhandlingcircuitboard,holditbytheedges.
2. Fastencircuitboardwithretainingscrews.
3. Connectalllinevoltage,lowvoltage,andaccessorywires.
4. Verifythesequenceofoperation.
Safety Considerations
Onlytrainedpersonnelshouldinstallorserviceheatingequipment.Whenworkingwithheating
equipment,besuretoreadandunderstandallprecautionsinthedocumentation,onlabels,andon
tagsthataccompanytheequipment.Failuretofollowallsafetyguidelinesmayresultindamageto
equipment,severepersonalinjuryordeath.
Introduction
TheICM291DSIgasignitioncontrolreplacesthefollowingCarriermodel:LH33WP003A.The
ICM291hasincorporatedLEDdiagnosticstoassistintroubleshooting.Faultcodeinformationcanbe
foundinthisapplicationguide.Pleasekeepthisapplicationguidewiththefurnaceinstallationmanual
forfuturereference.
Electrostatic Discharge (ESD) Precautions
CAUTION!
Use caution when installing and servicing the furnace to avoid and control electrostatic discharge;
ESD can impact electronic components. These precautions must be followed to prevent
electrostatic discharge from hand tools and personnel. Following the precautions will protect the
control from ESD by discharging static electricity buildup to ground.
1. Disconnectallpowertothefurnace.Donottouchthecontrolorthewiringpriortodischargingyour
body’selectrostaticchargetoground.
2. Togroundyourself,touchyourhandandtoolstoaclean,metal(unpainted)furnacesurfacenear
thecontrolboard.
3. Servicethefurnaceaftertouchingthechassis.Yourbodywillrechargewithstaticelectricityasyou
shufeyourfeetormovearound,andyoumustregroundyourself.
4. Regroundyourselfifyoutouchungroundeditems.
5. Beforehandlinganewcontrol,regroundyourself;thiswillprotectthecontrol.Storeusedandnew
controlsinseparatecontainersbeforetouchingungroundedobjects.
6. ESDdamagecanalsobepreventedbyusinganESDservicekit.
CAUTION!
To service control, and prior to disconnection, label all wires. Failure to do so may result in wiring
errors that can cause dangerous operation.
1. TurnthermostattoOFFpositionorsetittothelowestpossiblesetting.
2. TurnOFFelectricalsupplytofurnace.
3. TurnOFFgassupplytofurnace.
CAUTION:Failuretoturnoffgasandelectricsuppliescanresultinexplosion,re,death,or
personalinjury.
4. Removefurnaceblowerandcontrolaccessdoors.
5. Disconnectthermostatwiresandhumidierwires(ifequippedwithahumidier).
6. Disconnectlinevoltage,blower,electronicaircleanerwires(ifequipped),andtransformerwires.
7. Removescrewsandanyotherfasteners,andtheoldcircuitboard.
8. Examinecontrolandcontrolboxtocheckforwaterstains.
9. Makerepairsifanysourcesofwaterleakagearefound.Besuretocheckhumidiers,evaporator
coils,andventsystemsintheareaofthecontrol.
Remove Existing Control
SPECIFICATIONS
• Controlvoltage:24VAC(18-30VAC),60Hz
• Linevoltage:208/230VAC,60Hz
• Powerconsumption: 0.3Aplusgasvalvecurrentat24VAC
• OperatingTemperature: -40°C(-40°F)to75°C(176°F)
Timing
• Pre-purge:45seconds
• TrialforIgnition:5+2seconds
• Retryperiod:every20sec.for15min.
• Lockout:manualreset
• Post-purge:45seconds
Inputs
• Power:RTandC
• Thermostatinterface:R,WandG
• Safetyswitches:RS,LS,andCS
• CombustionmotorHallEffectsensor
• FlameSensing
Outputs
• Spark
• GasValve:GV
• Combustionmotor:CM
• Blowermotor:BM
• Indoorfanmotor:IFO
LEDindicators
• RedLED: SteadyON-normaloperation
  Flashing-faultcodes
ICM291 Gas Ignition Control Board
AWcallfromtheT’statwillengagethecombustionmotor.Ignitionsequencebegins,gasvalveand
sparkareengaged,providingthatsystemsafetyswitches(RS,LS,andCS)areclosedandthereis
feedbackfromthecombustionmotorHallEffectsensor.Theblowerandindoormotorswillengage45
secondsafterameisestablishedandsensed.Theydisengage45secondsafterWcallissatised.
AGcallfromtheT’statwillengageblowerandindoormotorsrightaway.Theydisengage25seconds
afterGcallisremoved.
Sequence of Operation
Flamenotestablished
1. Ifameisnotestablishedduringthe5+2initialsequencethenthecontrolwillstartthenexttrialfor
ignitionin20seconds.
2. Theattempttoignitewillcontinuefor15minutesbeforetherespectivefaultcodeistriggeredand
ignitiontrialsarestopped.
3.Thegasvalveisenergizedonlyduringtheignitionsequenceof5+2seconds.
4. Blowerandindoorfanmotorsareoffuntilameisestablishedand45secondslater.
Flameout
1. Flameoutisconsideredwhenameislostduringheating.
2. WhenWsignalispresentandameissensedoutthenthesparkwillstartrightaway.
3. Ifameisnotestablishedontheimmediatesequence(2above)thenthecontrolwillcontinue
attemptsevery20secondsfor15minutesbeforetherespectivefaultcodeistriggeredandignition
trialsarestopped.
4. Blowerandindoorfanmotorswillcontinuerunningduringameoutscenariofor15minutes+45
seconds.
5.Combustionmotorremainsonthroughouttheameoutscenario.
Flameoutofsequence
1. FlameoutofsequencerepresentsascenariowhenameissensedwhileWsignalisnotpresent.
2. Combustion,blowerandindoorfanmotorswillbeengaged(ifnotalreadyrunning)rightawayand
keeprunningforaslongasthefaultconditionispresent.
3. Theunitisoperablebutwilldisplaythefaultcodeconstantlyuntilreplacedbyanotherfaultcodeor
powerreset.
NosignalfromtheHallaffectsensor
1. OnaWcall,iftheinputfromtheHallaffectsensor(RA0)isnotpresentformorethanaminute,
thenthecombustionmotorwillcontinuerunningendlesslyandtherespectivefaultisashed.
2. DuringrunningstateiftheinputfromtheHallaffectsensorisnotsensedthenthegasvalvewill
shutoffrightaway,blowerandindoorfanmotorswillcontinuerunningfor30secondsandthen
turnoff,combustionmotorrunscontinuously.
Troubleshooting Tips
LED Fault Codes
#OfFlashes
representsConstant
ONNormal
operation
Results
1
Thecontrolhasmodiedthefanondelayto0andoffdelayto3minutes
duetosensingLStripwithin10minutesofacall
2
a) LSisopenduetohightemperature(fanisn’tworkingscenario)
b) Theunitwillnotstartatrialforignitionuntiltheswitchclosesback
3
a) Flamesensedoutofsequence.
b) Theunitisoperable,howeverwilldisplaythisfaultcodeuntilpower
resetoranothercode
4
a) LSopened4consecutivetimesduringacallforheating
b) ThefaultcodeisresetonthenextWcall
5
a) Ignitionlockout.Thecontroltriedunsuccessfullytoignitefor15minutes
b) Theunitwillnotoperate.Requirespowerreset
6
a) ThecombustionmotorisnotsensedrunningORCSopen
b) Theunitwillnotoperate.Requirespowerreset
7
a) RStripped
b) Theunitwillnotoperate.Requirespowerreset
8 a) Internalcontrolfault(softwareselfcheck)

ICM Controls ICM291 Specifications

General

Brand	ICM Controls
Model	ICM291
Category	Control Unit
Language	English