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Siemens
Basic Documentation RVP360
CE1P2546en
Building Technologies
18 Function block: Solar d.h.w.
2017-07-24
18.3.3 Minimum running time
When the collector pump is activated, it keeps running for a minimum time of tMin
= 20 seconds. This minimum on time applies to all functions that activate the col-
lector pump.
tMin
fSolar
ON
OFF
fSolar
Solar function
ON/OFF Collector pump
tMin
Minimum on time
To ensure the flow pipe from the collector to the storage tank is flushed with hot
water, deactivation of the collector pump after reaching the frost protection limit at
the collector sensor is delayed by the minimum running time.
tMin
ON
OFF
fFrost
fFROST Frost protection function solar
ON/OFF Collector pump
tMin
Minimum running time
18.3.4 Fost protection temperature for the collector
Operating line 203 is used to set the frost protection temperature for the collector.
If there is risk of frost at the collector, the collector pump is activated to prevent the
heat conducting medium from freezing.
ON
OFF
1 K
TKolFrost
TKol
Collector temperature
TKolFrost Frost protection temperature for collector
ON/OFF Collector pump
T
Temperature
t
Time
The collector pump is activated when the collector temperature drops below the
frost protection temperature: TKol < TKolFrost
The collector pump is deactivated when the collector temperature rises 1 K
above the frost protection temperature: TKol > TKo 1 K
Frost protection as
a special case