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Siemens Building Technologies
Basic Documentation RVP540 / RVP550
CE1P2488en
HVAC Products
Description of the heating engineer settings
18.10.2002
Speed-controlled solar pump
4.99 Functioning
The controller permits speed-controlled operation of solar collector pump Q5 or of heat
exchanger pump K9. The pump speed is changed in a way that an ideal differential
between the temperature at the sensor (B6 or B62) and that in the storage tank is
reached.
If the temperature differential is too great, the pump’s speed will be continually in-
creased until the “Maximum solar pump speed” (line 342) is reached; if it is too small,
the pump’s speed will be reduced until the “Minimum solar pump speed” is reached.
In addition, the controller makes advance assessments of the anticipated temperature
differential and initiates pump speed changes only if in agreement with the current
situation.
The speed of solar collector pump Q5 is controlled such that the temperature at sensor
B6 will be within the range called “const”, if possible.
23
92Z
48
B6
ON
OFF
Q5
+++
- - -
c o n s t.
ON
OFF
°C
t
TBx
TPx
2K
t
TBx / TPx
Actual value of the temperature at the heat exchanger of the d.h.w. or buffer storage tank
+ + +
Temperature range in which the pump’s speed increases
- - -
Temperature range in which the pump’s speed decreases
const.
Temperature range in which the pump’s speed remains constant
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Temperature differential ON heat exchanger
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Temperature differential OFF heat exchanger
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Minimum speed / maximum speed of the solar pump
solar collector pump Q5
