Tech Controllers ST-976 - Page 35

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Selectsensor
ItallowstheusertodecidewhichsensorshouldprovidedataforactivationoftheadditionalCHpump(CH
sensor,DHWsensor,valve1sensor,returnsensor,weathersensororadditionalsensor).
DHWpump
TYPEOF
DEVICE
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DHWPUMP
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Temperaturethreshold
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Hysteresis
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Pre‐settemperature
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Maximumtemperature
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Sensor1selection
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Sensor2selection
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Whenthisfunctionisactive,theadditionalpumpservesastheDHWpump.Thepumpisactivatedwhenthe
sensor1temperatureexceedsthetemperaturethreshold.Itremainsactiveuntilthetemperaturemeasured
bysensor2reachesthepre‐setvalue.Additionally,itispossibletosetthealarmtemperatureforsensor2.
Whenthisvalueisreached,anemergencyprocedureisactivated.
ThefollowingparametersneedtobeconfiguredforDHWpumptoworkcorrectly:
Activationthreshold
ThisoptionisusedtosettheDHWpumpactivationtemperature(thetemperaturemeasuredbysensor1which
readsthetemperatureoftheheatsource–theCHboiler).Belowthistemperaturethepumpremainsinactive
whereasabovethistemperatureitisenabledandoperatesuntilthepre‐settemperatureisreached.
Hysteresis
This option is used to define the hysteresis of the pre‐set temperature. When the pre‐set temperature is
reached,thedeviceisswitchedoff.Itwillbeswitchedonagainwhenthesensortemperaturedropsbelowthe
pre‐setvalueminushysteresis.
Example:
 If the pre‐set temperature is 60°C and the hysteresis value is 3 °C, the DHW pump is switched off
 whenthesettemperatureof60°Cisreached,anditisactivatedagainwhenthetemperaturedrops
 to57°C.
Pre‐settemperature
Thisoptionisusedtosetthepre‐settemperatureofthedevice.Whenthetemperatureisreached,thedevice
isswitchedoff.Thetemperatureismeasuredbysensor2.
Maximumtemperature
Thisoptionisusedtosetthemaximumtemperatureofsensor1(itreadsthe temperaturefrom theheat
source).Whenthetemperatureisreached,thedeviceisswitchedoffregardlessofthecurrenttemperature
onthesensor2.Itprotectstheinstallationagainstoverheating.