Viessmann Vitotronic 11 CC1E, Installation And Service Instructions Manual

Page: 41 / 120

41
External demand via switching contacts
!
Please note
Live contacts lead to short circuits or phase fail-
ure.
The external connection
must be potential-
free .
Two-stage burner
Function
External demand, burner
stage 1
External demand, burner
stages 1 and 2
External load-dependent
starting
Connection Plug
aVD
.1/
aVD
.2 Plug
aVD
.2/
aVD
.3
aVH
.2/
aVH
.3
143
A
B
2 3 1
A
Floating contact
B
To the control unit
143
A
B
2 3 1
A
Floating contact
B
Plug
aVD
of the control
unit
146
A
B
2 3 1
A
Floating contact
B
Plug
aVH
of the control
unit
Contact
■
Closed
■
Burner stage 1 is switched
on.
■
Burner stage 2 is switched
on only for maintaining the
minimum temperature.
■
The boiler water tempera-
ture is restricted by the
electronic maximum tem-
perature limiter if this limit-
er is set below the level of
the mechanical tempera-
ture controller.
■
Burner stages 1 and 2 are
switched on.
■
The boiler water tempera-
ture is restricted by the
electronic maximum tem-
perature limiter if this limit-
er is set below the level of
the mechanical tempera-
ture controller.
■
Burner stage 2 is switched
off 2 K below the maxi-
mum temperature.
■
The burner in the boiler is
switched on subject to
load.
■
The boiler water tempera-
ture is restricted by the
electronic maximum tem-
perature limiter or the me-
chanical temperature con-
troller.
■
Open Burner stage 1 is switched
off. Burner stages 1 and 2 are
switched off. The burner in the boiler is in
control mode.
Parameter
— —
Select the set boiler water
temperature in parameter
"0B" in the
"General" group.
External functions — single boiler system
Connecting the external control unit
(cont.)
5863679
Installation