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Siemens
Heating and D.h.w. Controller RVL481
CE1P2541en
Building Technologies
26 Function block "D.h.w. solar charging"
20.05.2008
26.2.3 Minimum
runtime
When the collector pump is switched on, it remains on for min. runtime tMin = 20 s. This
minimum runtime is enabled for all functions activating the collector pump.
25
4
1
D
0
7
t
tMin
fSolar
ON
OFF
fSolar Solar
function
ON/OFF Collector
pump
tMin Minimum
runtime
Collector pump switch-off is delayed by the minimum runtime after the frost protection
limit is reached to rinse the flow pipe between collector to storage tank with hot water.
25
4
1
D
0
8
tMin
ON
OFF
f Frost
fFROST Frost protection function solar
ON/OFF Collector
pump
tMin Minimum
runtime
26.2.4 Collector
frost
protection temperature
Operating line 203 is used to set the frost protection temperature for the collector.
The collector pump is operated if there is a risk of frost at the collector to prevent the
heat carrier from freezing.
T
ON
OFF
t
TKol
254
1D
09
1 K
TKolFrost
TKol
Collector temperature
TKolFrost
Collector frost protection temperature
ON/OFF Collector
pump
T Temperature
t Time
•
The collector pump switches on if the collector temperature drops below the frost pro-
tection temperature: TKol < TKolFrost
•
The collector pump is switched off if the collector pump rises above the frost protection
temperature by 1 K: TKol > TKo 1K.
•
The frost protection function is stopped if d.h.w. storage tank temperature drops below
8 °C.
Setting --- switches off the collector frost protection function.
Special case: Frost pro-
tection