Siemens AVS75.39 Series User Manual page 117

Medium evaporating -
temperature
Evaporation heat carrier
Impact of evaporation
monitoring
Speed control
Pump speed min /max
Yield measurement
Antifreeze
Pump capacity
Siemens
Building Technologies
Line no. Operating line
3860 Evaporation heat carrier
3862 Impact evaporation superv
On own collector pump ¦ On both collector pumps
If there is a risk of the heat carrying medium evaporating due to high collector
temperatures, the collector pump will be deactivated to prevent it from exceeding
certain temperature levels. This is a "Pump protection" function.
In the case of collector fields equipped with 2 collector pumps, it can be selected if
only the pump of the collector circuit with risk of evaporation or if both pumps shall
be deactivated.
Line no. Operating line
3870 Pump speed min
3871 Pump speed max
The charging setpoint of the storage tank with first-priority charging and the
collector temperature are used for speed control. A PI controller calculates the
speed required to ensure that the collector temperature lies 2 Kelvin below the
switch-on temperature.
If the collector temperature rises due to increased solar radiation, the speed is
increased. If the collector temperature drops below this setpoint, the speed is
reduced.
Parameters can be set to define a minimum and maximum pump speed.
Using these settings, minimum and maximum limitation of the pump speed is
provided.
Line no. Operating line
3880 Antifreeze
3881 Antifreeze concentration
3884 Pump capacity
To ensure accurate solar yield measurement, both additional sensors (B63 in the
solar flow and B64 in the solar return) should be connected. If one or both sensors
is/are missing, the controller uses collector sensor B6 or B61 and the respective
storage tank sensor B31 or B41 to make the calculation.
Accurate measurements are made with B63/B64.
The 24-hour and total solar energy yield (8526 and 8527) is calculated, based on
these data.
Since the mixing ratio of the collector medium has an impact on heat transmission,
the type of antifreeze used and its concentration must be entered in order to be
able to determine the energy yield.
For yield measurement without external pulse or flow measurement, the flow must
be determined corresponding to the built-in pump in l/hr and is used to calculate
the supplied volume.
This setting must be switched off if the flow is measured via Hx.
User manual RVS43.345
The settings in detail
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CE1U2354en_021
2013-09-02