ComfortNET CTK04 - Normal Operation; Programmed Recovery

System Installation Guide
16
69-2688—07 I/O-CHTSTAT03
Backup heat differential and upstage timer
Basic and Advanced Temperature Control Options (ISU 3010)
Abackupheatdifferentialandbackupheatupstagetimercanbesetonheatpump
systemswithbackupheat.Seeinstallersetupoptions(ISU3090-3110).
Normal operation
WhentheBackup Heat DifferentialissettoComfort,thethermostatusesbackup
heatasneededtokeeptheindoortemperaturewithin1°F(0.5°C)ofthesetpoint.
WhentheBackup Heat Differentialissetto2°Forhigher,backupheatisnotused
unless the indoor temperature drops to the Backup Heat Differential setting or the
Backup Heat Upstage Timerexpires,whicheveroccursfirst.Theupstagetimerstarts
whenthehigheststageofthepreviousequipmenttypeturnson.
Manual temperature change
WhentheBackup Heat DifferentialissettoComfort,thethermostatusesbackup
heatasneededtokeeptheindoortemperaturewithin1°F(0.5°C)ofthesetpoint.
WhentheBackup Heat Differentialissetto2°Forhigher,iftheheatpumpismak-
ingprogressasexpected,backupheatwillnotbeusedtoreachthenewsetpoint.
Settoahighernumbertouselessbackupheat(agreaterdifferencebetweenthe
currentindoortemperatureandthenewsetpointisrequiredtoturnonbackupheat).
Seenotesbelow.
Programmed recovery
Iftheheatpumpismakingprogressasexpected,backupheatwillnotbeusedto
reachthesetpointofthenextprogramperiod.Backupheatisalways restricted dur-
ingaprogrammedrecoverywhentheAdaptiveIntelligentRecoveryfeatureisused.
Seenotebelow.
Basic Options:TheInstallerSetupdisplaysbasictemperaturecontroloptions
whichincludeBackupHeatDifferential,BackupHeatUpstageTimerandOutdoor
TemperatureLockouts.Note:OutdoorTemperatureLockoutsonlyapplytoHeat
Pumpapplications.
Advanced Options:TheInstallerSetupdisplaysbothBasicandAdvancedOptions.
AdvancedtemperaturecontroloptionsincludeFinishWithHighCoolStage,Finish
WithHighHeatStage,TemperatureDifferentialsettingsbetweenallstagesand
CycleRatesettingsperstage.
During a programmed recovery (or when the temperature setpoint is changed by the user), the thermostat waits to turn on the
backup heat depending on system performance, load conditions and how many degrees the temperature setpoint is changed.
Backup heat will be used ONLY when the temperature is not rising quickly enough to reach the setpoint in a reasonable time.
If the backup heat was used in the last 2 hours because the heat pump was not able to maintain the setpoint, the thermostat
may turn on the backup heat earlier when the user raises the setpoint.
Finish With High Heat or Cool Stage - When a multi-stage heating or cooling system is used, this feature keeps the high stage
of the heating or cooling equipment running until the desired setpoint is reached.