Specifications
Electrical rating: • 24VAC(18-30VAC)
• 1ampmaximumperterminal
• 3ampmaximumtotalload
Temperature control range: 55°Fto90°F(13°Cto32°C)Accuracy:±1°F(±0.5°C)
System congurations:2-stageheat,2-stagecool
Timing: Anti-shortCycle:4minutes(bypassanti-shortcycledelaybyreturningtoOFFmodefor5seconds)
BacklightOperation:10seconds
Terminations:A,L,S1,S2,R,C,W1,Y1,W2,Y2,G,O
Package Contents/Tools Required
Package includes:910121748thermostatonbase,thermostatcover,wiringlabels,screwsandwallanchors,
Installation,OperationandApplicationGuide
Tools required for installation:Drillwith3/16”bit,hammer,screwdriver
Important Safety Information
WARNING!
:
Always turn off power at the main power supply before installing, cleaning, or removing
thermostat.
• Thisthermostatisfor24VACapplicationsonly;donotuseonvoltagesover30VAC
• Allwiringmustconformtolocalandnationalelectricalandbuildingcodes
• Donotuseairconditioningwhentheoutdoortemperatureisbelow50degrees;thiscandamageyourA/Csystem
andcausepersonalinjuries
• Usethisthermostatonlyasdescribedinthismanual
To Remove Existing Thermostat
ELECTRICAL SHOCK HAZARD
– Turn off power at the main service panel by removing the fuse
or switching the appropriate circuit breaker to the OFF position before removing the existing
thermostat.
1. Turnoffpowertotheheatingandcoolingsystembyremovingthefuseorswitchingtheappropriatecircuit
breakeroff.
2. Removecoverofoldthermostat.Thisshouldexposethewires.
3. Labeltheexistingwireswiththeenclosedwirelabelsbeforeremovingwires.
4. Afterlabelingwires,removewiresfromwireterminals.
5. Removeexistingthermostatbasefromwall.
6. Refertothefollowingsectionforinstructionsonhowtoinstallthisthermostat.
To Install Thermostat
ELECTRICAL SHOCK HAZARD
– Turn off power at the main service panel by removing the fuse
or switching the appropriate circuit breaker to the OFF position before removing the existing
thermostat.
IMPORTANT:Thermostat installation must conform to local and national building and electrical codes and
ordinances.
Note:Mount the thermostat about ve feet above the oor. Do not mount the thermostat on an outside wall, in
direct sunlight, behind a door, or in an area affected by a vent or duct.
1.Turnoffpowertotheheatingandcoolingsystembyremovingthefuseorswitchingtheappropriatecircuitbreaker
off.
2.Toremovecover,pullgentlyattheseamatthetop.
3.Putthermostatbaseagainstthewallwhereyouplantomountit(Besurewireswillfeedthroughthewireopening
inthebaseofthethermostat).
4.Marktheplacementofthemountingholes.
5.Setthermostatbaseandcoverawayfromworkingarea.
6.Usinga3/16”drillbit,drillholesintheplacesyouhavemarkedformounting.
7.Useahammertotapsuppliedanchorsinmountingholes.
8.Alignthermostatbasewithmountingholesandfeedthecontrolwiresthroughslitinthermalintrusionbarrierand
intowireopening.
9.Usesuppliedscrewstomountthermostatbasetowall.
10.Insertstripped,labeledwiresinmatchingwireterminals.
CAUTION!
:Be sure exposed portion of wires does not touch other wires.
11.Gentlytugwiretobesureofproperconnection.Doublecheckthateachwireisconnectedtotheproper
terminal.
12.Turnonpowertothesystematthemainservicepanel.
13.Congurethermostattomatchthetypeofsystemyouhave.
14.Replacecoveronthermostatbysnappingitinplace.
15.Testthermostatoperationasdescribedin“TestingtheThermostat”.
Parts Diagram
Icon Descriptions
Coolingoperationicon
Fanoperationicon
Heatingoperationicon
Roomtemperature
offsetactivated
1ST Cool 2ND Cool 1ST Heat 2ND Heat
Heat/Cool Y1 YI,Y2 W1 W1,W2
The910121748thermostatiscongurableforallsystems.Thecongurationdirectlyaffectstheoutputs.
Usetheoutputcharttocorrectlycongureandwirethethermostattoyoursystem.
910121748 Output Chart
Configuration Mode
OFF
PM
1. Verifythe910121748isintheOFFmode.
PresstheSYS(left)buttonuntiloffmodedisplays.
2. Removethecoverofthethermostatbygentlypullingnearoneofthecornersat
thetopofthethermostat.
3. PresstheCONFIGbuttonfor1secondwhilethe910121748isinOFF mode.
Toexitcongurationmode,presstheCONFIGswitchfor1second.
Presstheupordownbuttontochangesettingswithineachscreen.
Downbutton
Upbutton
Presstherightbuttontoadvancetothenextscreen.
Note:Pressing the
left
button will return you to the previous screen. Left
button
Right
button
Thecongurationmodeisusedtosetthe910121748tomatchyourheating/coolingsystem.Tocongurethe
910121748,performthefollowingsteps:
CONFIG
S1 S2 R C W
O/B GY1W2 W3Y2
RESET CONFIG
FP
6. Maximum Heat Setpoint(55°Fto90°F)(13°Cto32°C)
Adjusttocontrolthemaximumheatsettemperatureallowed.
Presstheupordownbuttontoselect.
Presstherightbuttontoadvancetothenextscreen.
7. Minimum Cool Setpoint(55°Fto90°F)(13°Cto32°C)
Adjusttocontroltheminimumcoolsettemperatureallowed.
Presstheupordownbuttontoselect.
Presstherightbuttontoadvancetothenextscreen.
9. Temperature Sensor(1-4)
1.Onlyon-boardsensordeterminesroomtemperature.
2.Onlyremotesensordeterminesroomtemperature.
3.Averagetemperatureofon-boardandremotesensor.
4.Onlyon-boardsensorwillbeuseduntilNITEperiod,andthenonlyremote
sensorisused.
Note:If there is no remote sensor, option 1 must be selected.
Presstheupordownbuttontoselect.
Pressthecongurationbuttonfortwosecondstoexitconguration.
8. Room Temperature Offset(+9°Fto-9°F)(+4.5°Cto-4.5°C)
Adjusttocalibratedisplayedroomtemperaturetomatchactualroomtemperature.
Note:When not set to 0, will display.
Presstheupordownbuttontoselect.
Presstherightbuttontoadvancetothenextscreen.
Configuration Mode Settings
ThesetupscreensforCongurationModeareasfollows:
1. Temperature Scale (ForC)
ChooseFahrenheitorCelsius.
Presstheupordownbuttontoselect.
Pressthe
right
buttontoadvancetothenextscreen.
2. 1st Stage Temperature Differential(1°Fto5°F)(0.5°Cto2.5°C)
Setthenumberofdegreesbetweenyour“setpoint”temperatureandyour“turnon”
temperature.
Presstheupordownbuttontosetdifferentialvalue.
Presstheright buttontoadvancetothenextscreen.
4. Staged Off Outputs
Selectwhethertheoutputsforheatingandcoolingarestagedoffindependentlyor
aresatisedsimultaneously.
1=outputsstagedoffindependently
0=outputsoffsimultaneously
Presstheupordownbuttontoset.
Presstheright buttontoadvancetothenextscreen.
5. Minimum Deadband(1°Fto9°F)(1°Cto5°C)
SettheminimumseparationbetweenheatsetpointandcoolsetpointinAuto
ChangeoverMode.
Presstheupordownbuttontosetdeadbandvalue.
Presstheright buttontoadvancetothenextscreen.
3. 2nd Stage Temperature Differential(1°Fto5°F)(0.5°Cto2.5°C)
Setthenumberofdegreesbetweenwhenstage1turnsonandwhenstage2turnson.
Presstheupordownbuttontosetdifferentialvalue.
Presstheright buttontoadvancetothenextscreen.
Wiring Diagrams
Conguration
switch
Resetswitch
Right(fan)button
Downbutton
Upbutton
S1 S2 R C GY1 W2 Y2
RESET CONFIG
Mode of Operation
The910121748isaprogrammable,manualorautochangeover,2-stageheat,2-stagecoolthermostat.Anoutdoor
sensorcanbeusedtomonitortheoutdoortemperature.
Thethermostatactivatestheheatingappliancewhentheroomtemperatureisbelowthesetheattemperature(by
thedifferentialtemperature).The910121748willstopoutputtingwhenthecallforheathasbeensatised.
Whentheroomtemperatureisgreaterthanthesetcooltemperature(bythedifferentialtemperature),thecooling
deviceisactivated.The910121748willstopoutputtingwhenthecallforcoolingissatised.
The910121748hasvepossibleoperatingmodes:OFF,Heat,Cool,Heat & Cool,andProgrammode.Inoff
mode,thethermostatwillnotturnonheatingorcoolingdevices.Themanualfancanbeturnedoninalloperating
modesusingthefanbutton.Inheatmode,thethermostatcontrolstheheatingsystem.Inthecoolmode,the
thermostatcontrolsthecoolingsystem.Inheat&coolmode,thethermostatcontrolsboththeheatingandcooling
systems.Inprogrammode,thethermostatwillautomaticallybecontrolledbythesetprogram.Programmodecan
functionwithheatmode,coolmode,orheat&coolmode.Theclockdisplayalternateswiththesettemperature
displayforheat&coolmode.
Theprogramschedulecanbeoverriddenbychangingthesettemperature(upordownbutton).Thisputsthe
910121748thermostatintoa2-hourtemporaryhold.After2hours,itwillautomaticallyreturntotheprogram
schedule.
TheprogrammablefanfeaturecanbeusedtorecirculateairwhileinProgrammode.Itisactivatedduringthe
programschedulesetup.
PressingtheUPandDOWNbuttonssimultaneouslyfor2secondsthenreleasingthemcausesthethermostatto
outputfromthe“O”terminalfor5seconds.“Or”willshowonthedisplay.Thiswillresultintheunitgoingintoanight
set-backoverride.
PressingtheUPandDOWNbuttonssimultaneouslyfor5secondscausesthethermostattooutputfromthe“O”
terminalfor10seconds.“rS”willshowonthedisplay.Thiswillresultintheunitbeingreset.
Button Functions
UP–Usedtoincreasethetime,settemperaturesandtoadjustconguration
settings.
DOWN–Usedtodecreasethetime,settemperaturesandtoadjust
congurationsettings.
SYS (left)– UsedtochangefromOFF,HEAT,COOLandAUTOchangeover
modes
FAN (right)–Usedtoturnonandofftheindoorfan.
PROG (SYS and FAN)–Usedtochangefromprogramoperationtomanualoperation.
DOWN and SYS–Pressedsimultaneouslytodisplayoutdoorremotetemperatureifremotesensoris
connected.
UP and DOWN– Usedtooverridenightsetbackorresettheunit.
PROG
FAN
(right)
Down
button
Up
button
SYStem
(left)
TerminalsS1andS2canbeusedforanindoorremotesensor.
Theindoorremotesensorisusedtoreadtheindoortemperature
inadifferentlocation.Thisisbenecialwhenthethermostatisnot
mountedintheideallocation.TheremotesensorP/Nis910116773.
1. Removecoverfromremotesensorhousing.
2. Selectanappropriatelocationformountingtheremotesensor.
3. Mountremotesensorunitusinghardwareprovided.
4. Installtwostrandshieldedwirebetweenremotesensorand
thermostat.Shieldedwireisrecommended.
Do notrunremotesensorwireinconduitwithotherwires.
• Wire 1shouldrunbetweentheS1terminalonthethermostat
andtheS1terminalontheremotesensor
• Wire 2shouldrunbetweentheS2terminalonthethermostatandtheS2terminalontheremotesensor
• ConnecttheshieldingofthewiretotheS2terminalonthethermostat
5. Congurethethermostattooperatewiththeremoteindoorsensor(seeCongurationModesetting9).
Remote Sensor Installation (Optional)
Note: Remote or outdoor sensor reading can be
displayed by simultaneously pressing the
Down and SYS buttons.
Remote Sensor:
(Contact Daikin for optional remote sensor.)
Terminal Designator Descriptions
R–24VAChot
C–24VACcommon
W1–1ststageheat
Y1–1ststagecool
W2–2ndstageheat
Y2–2ndstagecool
G – Fan
A – Alarminput
L – Statusinput
O – Override/reset
L
S1
S2
R
C
W1
Y1
W2
Y2
G
A
O
O
G
Y1
Y2
W1
W2
A
R
C
4
3
2
1
5
O
G
Y1
Y2
W1
W2
A
R
C
ICM
Thermostat
Terminal
TB2
TB1
ICM
Thermostat
Terminal
