SystemAir TA 4500 HW

4.3Freecooling
Thisfunctionisusedduringthewarmperiodtosaveenergybyusingcoldoutdoorair,e.g.duringnight
time,tocooldownthebuilding.
Note:
ThefollowingisonlyvalidifthefreecoolingfunctionissettoActiveintheprogrammenu.
Inorderforthefreecoolingfunctiontowork,atotalof3temperaturesensors(outdoor,supplyand
extract/room)arerequired.
Freecoolingisonlyactivatedwhenthefollowingstartingconditionsaremet.
Startingconditions:
•Lessthan4dayshavepassedsincetheunitwaslastinrunningmode
•Theoutdoortemperatureduringthepreviousrunningperiodexceededasetlimit(+22°C)
•Itisbetween00:00and07:00:00intheday(settable)
•Thetimeroutputsfornormalspeed,ExtendedrunningnormalandExternalstopareOff
•AtimechannelwillbeOnsometimeduringtherecentlystarted24hours.
Theunitchecksthenighttemperature(indoorandoutdoortemperature)during3minutesattheset
startinghourwhenthefansarestartedsothatthesensorscanperformatemperaturemeasurement.
Ifaboveconditionsaremetthefreecoolingfunctionisstarted,ifnottheunitgoesbacktoOFFposition.
Iftheoutdoorsensorisnotlocatedintheoutdoorairinletductandaroomsensorhasbeenselected,
theunitwillnotstartfreecoolingaslongasallthetemperaturesarenotwithinthestartandstop
temperatureintervals.
Stopconditions:
•Outdoortempabovethesetmaxvalue(+18°C)orbelowthesetminvalue(condensationrisk,+10°C)
•Theroomtemp/extractairtempisbelowthesetstopvalue(+18°C)
•Oneofthetimeroutputsfornormalspeed,ExternalstoporExtendedrunningnormalisOn
•Thetimehaspast07:00:00.
Whenfreecoolingisactive,thefansrunatnormalspeedorthesetvalueforpressure/owcontrolandthe
digitaloutputFreecoolingisactive.TheoutputsY1-Heating,Y2-HeatexchangerandY3-Coolingareshut
down.Afterfreecoolinghasbeenactivated,theheatingoutputisblockedfor60minutes(congurable).
5InterfaceDescription
5.1ControlPanel
TheSCPcontrolpanelisdeliveredwitha10mcable(upto100mcanbeused)thatisconnectedto
thepanelandwithafastcouplingcontact,connectedtotheT opvexunit.Thecontactisconnectedto
theCorrigocontrollerintheelectricalconnectionbox.Thecablecanbeunscrewedinthebackofthe
controlpanel(gure5).
TA450-4500
OperationandMaintenanceInstructions
132616
8
SystemairSverigeAB