Viessmann SCU345 Manual page 31

System 9
3-tank solar system with east-/west collectors
The controller compares the temperatures at the col-
lector sensors S1 and S3 to the tank temperatures
at the sensors S2, S4 and S5. If one of the measured
Ventillogik
temperature differences is higher than the adjusted
switch-on temperature differences, the corresponding
pump (R1, R2) will be activated and the correspond-
Ventillogik 1
2
1
3
2
4
ing tank will be loaded up to the adjusted maximum
temperature via the valves R3, R4. In this system, one
of the tanks can be loaded with priority.
Sensor/
terminal
S1
S2
S3
S4
S5
V40
Relay
R1
R2
R3
R4
Valve logic
Ventillogik
Flow direction when the
Durchflussrichtung
im stromlosen Zustand
valve is normally open
Durchflussrichtung
im stromlosen Zustand
Designation Description
TCOL Temperature collector 1
TST1B Temperature tank 1 bottom
TCOL2 Temperature collector 2
TST2B Temperature tank 2 bottom
TST3B Temperature tank 3 bottom
optional: fl owmeter
Description
Solar pump tank 1
Solar pump tank 2
Valve tank 1/2, 3
Valve tank 2/3
1
2
3
4
Durchflussr
im stromlo
31