Viessmann VITOTRONIC 100 Installation And Service Instructions Manual page 30

Heating system designs
System version 8
Possible applications
If the distributor is located in remote
sub−stations (>20 m), and the heating
circuits require heat immediately
after a demand is present, e.g. blown
air heaters. The heat transfer to the
heating circuits must be able to be
reduced. The cascade and cylinder
control must be provided by a higher
control unit.
The distribution pump will be
regulated by the higher control unit.
It must be started when a boiler is
enabled.
If the actual temperature falls below
the required minimum return
temperature, temperature sensor T1
reduces or closes the mixer in
proportion.
Size the distribution pump to 110 %
of the total heating system flow rate.
The injection circuit provides heat to
the consumers immediately upon
demand. For this purpose, the
three−way mixer will be controlled.
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.
30
(cont.)
Temperature sensor T1
Wiring for reducing the volume flow
in heating systems with heating
circuit control units, which are not
connected to the boiler control unit
via the LON BUS.
Required coding: "0d:
"4C: 2".
L1
C
N
PE
20 A1 20 A1
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
1" and
K1 K2
D
A
closed closed closed
B
1 2 . . . n