Viessmann VITOPLEX 300 Type TX3A - Auxiliary functions for multi-boiler systems with the Vitotronic 300-K and Vitotronic 100, type GC1 via LON

External changeover of multi-stage/modulating burners
■
Contact A open:
Modulating operation
■
Contact A closed:
Two-stage operation
Set coding address "02" accordingly.
Auxiliary functions for multi-boiler systems with the Vitotronic 300-K and Vitotronic 100, type GC1 via LON
Plugs aVD and aVH at the Vitotronic 300-K
146
A
B
C
143
1 2 31 2 3
A
Change of external heating program/mixer "open"
B
External blocking/mixer "close"
C
External demand
A
,
B
and
C
are zero volt contacts.
External heating program changeover/mixer open
Closing contact
A
can change the manually selected heating pro-
gram or open the connected mixers.
In coding address "9A", the external function mixer "open" can be allo-
cated to the individual heating circuits.
In coding address "91", the external heating program changeover can
be allocated to the heating circuits.
Operating programs
Symbol Description
9 Central heating OFF and DHW OFF
w Central heating OFF and DHW ON
rw Central heating ON and DHW ON
Subject to the setting of coding address "d5", the system can be
changed from three manually selectable heating programs
9
,
w
,
rw
(contact open) either to
9
or
rw
(contact closed).
External blocking/mixer Close
Closing contact
B
causes the burner to shut down or the mixer to be
closed.
In coding address "99" you select which heating circuits are affected
by the function external blocking or mixer "Close".
Note
The frost protection of the relevant boiler or heating circuit is no longer
effective during the controlled shutdown or when the mixer "Close",
i.e. the lower boiler water temperature or flow temperature are no lon-
ger maintained.
External demand
Closing contact
C
starts the burner or boiler subject to load.
The boiler water temperature is limited via the maximum set boiler
water temperature or via the mechanical control thermostat.
The set value is selected in coding address "9b".
Plug
aVD
at the Vitotronic 100, type GC1
143
B
A
1 2 3
A
Boiler blocking
B
Start boiler as the last one in the boiler sequence
A
and
B
are zero volt contacts.
Boiler blocking
■
Contact A closed:
The boiler is blocked and removed from the boiler sequence, i.e. the
butterfly valve or the three-way mixing valve for constant return tem-
perature control is closed; shunt or boiler circuit pumps are switched
OFF. The other boilers must provide the required heating.
Note
The heating system is no longer protected against frost if all boilers
are blocked or when there are no other available boilers.
■
Contact A open:
The boiler is reinstated into the current boiler sequence.
Start boiler as the last one in the boiler sequence
■
Contact B closed:
The boiler is started as the last one in the boiler sequence.
The heat demand of the heating system is being met by the other
boilers.
This boiler is started if the output of the other boilers is inadequate.
■
Contact B open:
The boiler is returned into the current boiler sequence.
Control units
(cont.)
OIL/GAS BOILERS
VIESMANN
71
5822 426 GB
11