TheapplicationA275.3isveryflexible.Thesearethebasic
principles:
Heating(circuit1):
Typically,theboilertemperatureisadjustedaccordingtoyour
requirements.TheboilertemperaturesensorS3isthemost
importantsensor.Itmustbeplacedcorrectlyinordertomeasure
theboilertemperature.ThedesiredboilertemperatureatS3is
calculatedintheECLcontroller,basedontheoutdoortemperature
(S1).Thelowertheoutdoortemperature,thehigherthedesired
boilertemperature.Theboilertemperatureisalsotheflow
temperatureinthedirectconnectedheatingcircuit.
Bymeansofaweekschedule(upto3‘Comfort’periods/day),the
heatingcircuitcanbein‘Comfort’or‘Saving’mode(twodifferent
temperaturevaluesforthedesiredroomtemperature).In'Saving'
modea'Totalstop'functioncanbeselectedinordertoswitchOFF
theheating.
TheburnerisswitchedONwhentheboilertemperatureis
lowerthanthedesiredboilertemperatureandswitchedOFF
whentheboilertemperatureishigherthanthedesiredboiler
temperature.AswitchingdifferencedeterminestheON/OFF
control.Furthermore,theboilerprotectionfunctionwillonly
switchONthecirculationpumpiftheboilertemperaturegets
aboveaminimumtemperature.AminimumON-timecanbesetfor
theburnerinordertoincreasetheboiler'sefficiency.
Thereturntemperature(S5)totheboilershouldnotbetoo
high(condensingboiler)ortoolow(oilorgasfiredboiler).Ifso,
thedesiredboilertemperaturecanbedecreasedorincreased.
Furthermore,thereturntemperaturelimitationcanbedependent
oftheoutdoortemperature.Typically,thelowertheoutdoor
temperature,thehighertheacceptedreturntemperature.
Ifthemeasuredroomtemperature(measuredbyS7ortheremote
controlunitECA30)doesnotequalthedesiredroomtemperature,
thedesiredboilertemperaturecanbeadjusted.
Thecirculationpump(P1)isONatheatdemandoratfrost
protection.
TheheatingcanbeswitchedOFFiftheoutdoortemperaturegets
higherthanasetvalue.
TypicalA275.3application:
*Pressurereliefvalve
Theshowndiagramisafundamentalandsimplifiedexampleanddoes
notcontainallcomponentsthatarenecessaryinasystem.
AllnamedcomponentsareconnectedtotheECLComfortcontroller.
Listofcomponents:
S1
Outdoortemperaturesensor
S2
Returntemperaturesensor,circuit2
S3
Boilertemperaturesensor,circuit1
S4
Flowtemperaturesensor,circuit2
S5
Returntemperaturesensor,circuit1
S6
DHWtanktemperaturesensor
S7Roomtemperaturesensor/ECA30,circuit1
S8Roomtemperaturesensor/ECA30,circuit2
M2
Motorizedcontrolvalve,circuit2
P1
Circulationpump,circuit1
B1Burner
P3
DHWheatingpump,circuit3
P4
Circulationpump,circuit2
Thecontrollerispre-programmedwithfactorysettingsthatareshown
intherelevantchaptersofthisguide.
8|©Danfoss|2017.09
VI.GU.L2.02
OperatingGuideECLComfort210/296/310,applicationA275/A375