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Siemens Building Technologies
Basic Documentation RVP540 / RVP550
CE1P2488en
HVAC Products
Description of the EXP settings
18.10.2002
5.1.1 Frost protection for the plant
Depending on the current
outside temperature
, the released pumps will be activated
although there is no demand for heat.
Outside temperature
Pump
Diagram
...-4 °C
Continuously ON
ON
-5...10.5 °C
ON for 10 minutes at 6-hour intervals
takt
1.5 °C...
Continuously OFF
OFF
Between -4...-5 °C, different statuses can occur. In that range, it is important which
situation had existed before:
If the temperature was previously higher (in the range of "takt“), the pump will also cycle
in the temprature range from –4 to +5 °C, and is continuously ON only when the tempe-
rature drops further.
If the temperature was previously lower (in the range of ON), the pump is continuously
running also in the range up to –4 °C and switches on / off only when the outside tem-
perature is higher.
-2
23
71
Z
30
TA °C
OFF
0
1
2
3
4
-3
-4
-5
-6
-1
takt
ON
Exception
