en
40
Installation
Indications,
functions and options
Messages
Commissioning
Operation and function
Arrangement 9: Solar system with heating-circuit return preheating
The controller calculates the temperature difference between collector sensor S1
and store sensor S2. If the difference is larger than or identical to the adjusted
switch-on temperature difference (DT O), the solar pump will be activated by relay
1, and the store will be loaded until the switch-off temperature difference (DT F) or
the maximum store temperature (S MX) is reached.
Heating-circuit return preheating will be activated by relay 2, if the temperature dif-
ference between sensors S3 and S4 is larger or identical to the adjusted switch-on
temperature difference (DT3O). For this purpose, relay 2 controls the 3-port valve.
S3 can optionally be used as the reference sensor for the store emergency shut-
down option (OSEM). If the heat quantity measurement option (OHQM) is activat-
ed, S1 or VFD can be used for measuring the temperature (see table on p. 63).
PWM 2
PWM 1
VFD
L
N
R1
N
20
19
18
17
16
15
14
13
12
1 2
N R2
S2
S1
S3
S4 VBus
3 4 5 6 7 8 9 10
S1
S2
S4
R2
R1
S3 /
TSTT
VFD / TR