Technical data

51
Installation – Vitotronic 100, GC1
Connection of external controls
A
Boiler disable
Connect dry contact at terminals “1”
and “2” of the plug aVD.
Contact closed:
The boiler burner is disabled.
It is taken out of the boiler sequence,
i.e. isolation valve/return valve are
closed. The shunt pump/boiler circuit
pump are switched off. The heat must
be supplied by other boilers.
¨ Safety instruction!
If all boilers are disabled or no other
boilers are ready for operation, there is
no frost protection of the heating
sysytem.
Contact open:
The boiler is put back in the current
boiler sequence.
A Boiler disable
B Activate boiler as last in the boiler
sequence
C External changeover between
staged/modulating burner
B
Activate boiler as last in the boiler
sequence.
Connect dry contact at terminals “2”
and “3” of the plug aVD.
The boiler is activated as last in the
boiler sequence. The other boilers take
over the supply of heat for the heating
system. If the output of the other
boilers is not sufficient, the boiler is
activated.
Contact open:
The boiler is put back in the current
boiler sequence.
C
External changeover between
staged/modulating burner
Connect dry contact to terminals “1”
and “2” of the plug aVH.
Contact open: Modulating operation
Contact closed: Two-stage operation
The burner type must be set to
modulating in coding 1
(coding “02: 2”).
Please note:
When the burner type is scanned,
“modulating” continues to be displayed
after external changeover (the display
in not changed).
5351 340 v1.4
143
A
146
B
C