External Heat Exchanger With Solar Control Module - Viessmann VITOSOL SERIES Technical Manual

Solar control units
Systems with Vitotronic control units and KM BUS
Control units from the current product range are equipped with the
necessary software. When retrofitting an existing system, the boiler
control unit may have to be equipped with a PCB (see Viessmann
pricelist).
Boiler control unit settings
Systems with additional Viessmann control units
R1-R6 AC 250V 0.8 A
R7
AC 250V 4(2) A
A
T40
9
IP20
230V ~ 50-60 Hz
P = 3VA
B
C
D
E
A Wiring chamber of the solar control unit
B Contactor relay

External heat exchanger with solar control module

S1
R1
S3
VIESMANN
44
(cont.)
Grid
Réseau électrique
T6.3A
Red eléctrica
230V
L
N
27 30 31 32 33 34 35
N N N N N
L
N
?
M
1~
F
S2
R2
■ The set DHW temperature 2 must be encoded
■ The DHW phase 4 for DHW heating must be enabled
This signal is then relayed via the KM BUS to the solar control unit.
The transfer pump starts at an adjustable time if the DHW cylinder has
not reached 60 ºC at least once per day.
C Resistor (on site) for
PTC: 560 Ω
NTC: 8.2 kΩ
(subject to the type of boiler control unit)
D To the boiler control unit; connection for cylinder temperature
sensor
E Cylinder temperature sensor of the boiler control unit
F Transfer pump
The transfer pump starts at an adjustable time if the DHW cylinder has
not reached 60 ºC at least once per day.
A resistor simulates a DHW temperature of approx. 35 ºC.
The transfer pump is connected to relay output R3 or R5, irrespective
of which relays are already assigned standard functions.
The DHW cylinder is heated via the heat exchanger. The secondary
pump R2 starts in parallel with the solar circuit pump R1.
If an additional temperature sensor S3 is used, the secondary pump
R2 is switched on when solar circuit pump R1 is running and the
required temperature differential between S2 and S3 is available.
VITOSOL