Johnson Controls HICM008B21S - 5.4.1.4 Room Thermostat Control; Field-Supplied Room Thermostat Wiring and Operation

5-12
SM-18003
EXTERNAL INPUT/OUTPUT AND FUNCTION SETTING
5.4.1.4 ControlbyField-SuppliedRoomThermostat
[InputSetting:Code(01)(forCooling),Code(02)(forHeating)]
Inacasewhereaeld-suppliedroomthermostatisusedinsteadoftheinletthermistoroftheindoorunitin
ordertorun/stopthecompressor,connectwiresasshownbelow.
Operation
CoolingOperation: CompressorisONbyclosingterminals2and3ofCN3
  CompressorisOFFbyopeningterminals2and3ofCN3
HeatingOperation: CompressorisONbyclosingterminals1and2ofCN3
  CompressorisOFFbyopeningterminals1and2ofCN3
2
Temperature
Increase
Thermostat
CN3
3
2
1
3
1
Indoor Unit PCB
3P Connector
Field-Supplied Room Thermostat
Example: Room Thermostat Input (for Cooling) is set to terminals 2 and 3 of CN3
Room Thermostat Input (for Heating) is set to terminals 1 and 2 of CN3
NOTE:
The contact capacity of a thermostat
shall be DC12V and several mA. Select a
thermostat which makes and breaks the
contact with this capacity.
( )
NOTE:
1.MakethewiresCN3asshortaspossible.Donotinstallthewiresalongthe220Vpowerline.Install
themmorethan12in.(30cm)awayfromeachother.(Intersectingthemisacceptable.)
 Ifthewiresareinstalledalongthepowerline,complywiththefollowingpointstopreventnoise.
 a.Passeitherofthelowvoltagewireand220Vpowerlinethroughametaltubeandgroundoneend.
 b.Useashieldedwireforalowvoltagewireandgroundoneend.
 Themaximumwiringlengthis230ft.(70m).
2.Whenusingthisfunction,itisrecommendedthatsafetydevicessuchasanelectricleakagebreakeror
smokedetector,etc.,beusedbecausethisisanunattendedfunction.
3.Forathermostat,donotuseathermostatwhichusesmercuryforaswitch,becausechatteringislikelyto
occur at ON/OFF.
4.Useathermostatwithadifferentialof2
o
F (1.5
o
C)ormore.
5.Complywiththefollowingpoints.Ifnot,ahigh-voltagecircuitbreakerwillbeactivatedortheunitwill
repeat ON/OFF operation.
 a.Installathermostatwhereairinlettemperaturecanbedetectedcorrectly.
 b.Installathermostatwheredischargeairfromtheunitdoesnotblowdirectlyagainstit.
6.Whenusingaroomthermostat,seteachroomthermostat(forcoolingandheating)correctly.Ifanyof
themissetincorrectly,otherroomthermostatsdonotoperate.