Viessmann VITOTRONIC 100 Installation And Service Instructions Manual page 18

Heating system designs
System version 4
Possible applications
Heating systems with distributor
installed close to the boiler. The
boiler water volume flow will be
reduced by the motorised butterfly
valve.
In multi−boiler system without
Vitotronic 333, cascade and cylinder
control must be provided by a higher
control unit.
If the factory−set temperatures are
not reached at the Therm Control
temperature sensor, Therm Control
will regulate the motorised butterfly
valves. Where Therm Control cannot
affect the motorised butterfly valves
it must, instead, regulate the mixers
of the downstream heating circuits.
In the start−up phase (e.g. during
commissioning or after a night or
weekend shutdown), the boiler water
volume flow must be reduced by at
least 50 %.
The boiler is best protected when
regulating the heating circuits via
Vitotronic 050 connected to the
boiler control unit.
No additional on−site protective
measures are required.
Required coding: "0d:
18
(cont.)
1".
Therm−Control
Wiring in heating systems with
heating circuit control units which
are not connected to the boiler
control unit via the LON BUS.
Required coding:
"0d: 1" and "4C:
L1
C
N
PE
A1 A1
20 20
A
A
sÖ A1 Mixers closed
A
Contactor relay,
part no. 7814 681
B
Downstream heating circuit
controller, contact closed:
Signal for "Mixer closed".
C
Mains electrical connection
230V~/50 Hz
D
Junction box, on site
2".
K1 K2
D
A
closed closed closed
B
1 2 . . . n