Viessmann SCU345 Manual page 22

System 6
3-tank solar system with pump logic and priority logic
The controller compares the temperature at sensor
S1 to the temperatures at sensors S2, S4 and S5. If the
measured temperature differences are higher than the
adjusted switch-on temperature differences, the pump
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(R1, R2 and/or R3) will be activated and the corre-
sponding tank will be loaded up to the adjusted maxi-
mum temperature at most. Priority loading or parallel
loading can be carried out in this system.
Sensor/
Designation Description
terminal
S1 TCOL Temperature collector
S2 TST1B Temperature tank 1 bottom
S3 Optional sensor for measure-
ment purposes or options
S4 TST2B Temperature tank 2 bottom
S5 TST3B Temperature tank 3 bottom
V40 Optional sensor for measure-
ment purposes or options
Relay Description
R1 Solar pump tank 1
R2 Solar pump tank 2
R3 Solar pump tank 3
R4 optional:
Thermal disinfection
Parallel relay
Heat dump