Return Diversion - Siemens LMS14 User Manual

Temp diff on/off return div
Compar temp return div
Optg action return
diversion
Building Technologies Division
6.17.6

Return diversion

When there is a certain temperature differential between sensor B73 and the selectable
comparative temperature, the return flow is diverted through the lower section of the
buffer storage tank. The function can be used for Return temperature increase or
Return temperature decrease. The selection is made via Optg action return diversion
(4796).
In addition, the setting of the respective relay output is to be made as Buffer return
valve Y15 in configuration Relay output QX1, 2, 3, 4 (Relay output QX1(5890), Relay
output QX2 (5891), Relay output QX3 (5892), Relay output QX4 (5894)) and sensor
B73 at BX.
Line no. Operating line
4790 Temp diff on return div
4791 Temp diff off return div
The selected temperature differential defines the switch-on/off point of return diversion.
Line no. Operating line
4795 Compar temp return div
With B4
With B41
With B42
Selection of the buffer sensor with which the return temperature is compared to switch
the return diversion based on the selected temperature differential.
Line no. Operating line
4796 Optg action return diversion
Temp decrease
Temp increase
Temp decrease
If the consumers' return temperature is higher than the temperature at the selected
sensor (Compar temp return div (4795)), the return can be used to preheat the lower
storage tank section. As a result, the return temperature drops further which, in the
case of a condensing boiler, leads to higher efficiency.
Temp increase
If the consumers' return temperature is lower than the temperature at the selected
sensor (Compar temp return div (4795)), the return temperature can be raised by
diverting the return through the lower storage tank section. As a result, the return
temperature increases.
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28.01.2015