ThebasicprinciplesforapplicationP318.2:
DHWtemperatureandbuffercontrol
IfthemeasuredDHWtemperatureS4islowerthanthedesired
DHWtemperature(setincircuit1,favoritedisplay1),themotorized
controlvalveM2opensgraduallyformorewaterfromthebuffer
tank.
Coldtapwateris,viatheheat-exchanger,usedtocontroltheDHW
temperatureS4ifthetemperaturegetshigherandwillgradually
closethecontrolvalveM2.
TheDHWtemperaturesensorS4,thechargingtemperaturesensor
S3,thesupplytemperaturesensorS2andthebuffertemperature
sensorsS6andS8arethemostimportantsensorsandmustbe
connected.Ifoneofthementionedtemperaturesensorsisnot
connected,thecontrolvalveM1willclose;alternatively,thecontrol
pumpP1/V1willstop.
ThebufferchargingtemperatureatS3isbasedonthesetdesired
buffertemperatureatS6(setincircuit2,favoritedisplay1).
Optional:TemperaturecontrolofthecirculationpipeatS9ensures
thedesiredtemperaturebymeansofON/OFFcontrolofpump
P3orspeedcontrolofpumpV3.
Startbufferchargingprocess:
1.BuffertemperatureS6temperaturegetslowerthan('Desired
chargingtemperature'+'Startdifference').
Anexample:70°C+(-5)=65°C
2.X1isswitchedON
3.M1opens(alternatively,P1/V1isswitchedON/presetspeed)
inordertoincreasethesupplytemperature
S2.Returntemperaturelimitationisrespected.
4.P2/V2isswitchedONwhensupplytemperatureS2getshigher
than('Desiredchargingtemperature'+'Pumpstartdiff.').
Anexample:70°C+3K=73°C
V2startswithminimumspeed,forexample20%.
5.M1(orP1/V1)controlsthechargingtemperatureatS3.
6.V2increasesthespeedaslongasthechargingtemperatureS3
ishigherthan(desiredchargingtemperature-2K).
Stopbufferchargingprocess:
1.BuffertemperatureS6temperaturegetshigherthan(2K+
'Desiredchargingtemperature'+'Startdifference)
AND
LowerbuffertemperatureS8getshigherthan('DesiredDHW
temperature'+'Stopdifference).
Anexample:S6temperaturehigherthan(2+70°C+(-5)=
67°C)
ANDS8temperaturehigherthan(70°C+(-8)=62°C).
2.P2isswitchedOFF,respecting'DHWPpost-run'.V2changes
to0%.
NOTE:Post-runisnotrespectedifchargingtemperatureS3islower
thandesiredchargingtemperature.
3.X1isswitchedOFF.
4.M1closes(alternatively,P1/V1stops).
P318.2,ex.a,applicationwithcontrolvalveforbuffertemperaturecontrol:
Theshowndiagramisafundamentalandsimplifiedexampleanddoes
notcontainallcomponentsthatarenecessaryinasystem.
AllnamedcomponentsareconnectedtotheECLComfortcontroller.
Listofcomponents:
ECL310
ECLComfort310controller
ECA32
Built-inextensionmodule,0-10Voutputs
ECA35
Built-inextensionmodule,0-10Voutputsand
PWMoutputs
S2
(mandatory)Supplytemperaturesensor
S3
(mandatory)Chargingtemperaturesensor
S4
(mandatory)DHWtemperaturesensor
S5Returntemperaturesensor
S6
(mandatory)Buffertemperaturesensor
S8
(mandatory)Lowerbuffertemperaturesensor
S9
DHWcirculationreturntemperaturesensor
S12
0-10VinputfordesiredtemperatureatS6
P2
Chargingpump(ON-OFFcontrolled)
V2
Speedcontrolofchargingpump(0-10VorPWM)
P3
Circulationpump(ON-OFFcontrolled)
V3
Speedcontrolofcirculationpump(0-10Vor
PWM)
M1
Motorizedcontrolvalve(3-pointcontrolled)
M2
Motorizedcontrolvalve(3-pointcontrolled)
X1
Bufferheatingdemandsignal
X2
Anti-bacteriafunctionisactive
A1
Alarm
14|©Danfoss|2018.08
VI.JM.Q5.02
OperatingGuideECLComfort310,applicationP318