96/118
Siemens
Heating and D.h.w. Controller RVL481
CE1P2541en
Building Technologies
26 Function block "D.h.w. solar charging"
20.05.2008
T
t
1 K
1 K
SD
ON
254
1
D
10
TKol
TSp
ON
OFF
2 K
TRk
SD
ON
Temperature differential ON
ON/OFF Collector pump
TRk Recooling
setpoint
T
Temperature
TSp Storage
tank
temperature
t
Time
TKol Collector
temperature
•
The collector pump is switched on if the storage tank temperature is at least 2 K
above the recooling setpoint and above the collector temperature by temperature
differential ON.
TSp > TRk + 2 K and TSp > TKol + SD
ON
•
The collector pump is switched off if the collector temperature rises to 2 K of the stor-
age tank temperature.
TKol > TSp – 2 K
•
The function is stopped if the storage tank temperature reaches the recooling
setpoint to 1 K.
TSp < TRk +1 K
26.2.7 Evaporation
temperature of heat carrier
Operating line 205 allows for setting the evaporation temperature of the heat carrier.
If there is a risk of evaporation at the heat carrier (due to the high collector tempera-
ture), the collector pump is switched off to prevent it from running hot. This is a pump
protection function.
T
ON
OFF
TVerd
t
TKol
254
1D
1
1
15 K
TVerd
Evaporation temperature of heat carrier
TKol Collector
temperature
ON/OFF Collector
pump
T Temperature
t Time
•
The collector pump is switched off if the collector temperature exceeds the evaporation
temperature:
TKol > TVerd
•
The collector pump is again switched on if the collector temperature drops below the
evaporation temperature by 15 K:
TKol < TVerd – 15 K
Setting --- switches off the pump protection function.
The heat carrier evaporation protection (pump off) takes priority over overheating pro-
tection which would switch on the pump.