Viessmann Vitotronic 200 Installation And Service Instructions For Contractors page 30

Electrical connections
External functions
Function External changeover, stepped / modulating burner
Contact
Closed Two-stage operation
■
Open Modulating operation
■
Parameter Set parameter "02:2" in the "Boiler" group.
Note
When calling up the burner version, the address for modulating appears even after an ex-
ternal changeover (it is not rewritten).
External demand
!
Please note
Live contacts lead to short circuits or phase fail-
ure.
The external connection must be potential-
free.
Function
Control unit Vitotronic control
Connection Plug
1
A
B
30
(cont.)
unit
.2/ .3 DE1, DE2 or DE3
aVH aVH
A
DE1
2 3
146
A
B
A
B
Floating contact
Plug aVH of the
control unit
External demand
EA1 extension
B
DE3
DE2
A A
Floating contact
EA1 extension
0 to 10 V input
Note
Ensure galvanic separation be-
tween the earth conductor and the
negative pole of the on-site power
source.
[{{] 0-10V aBJ f-]
A
+ - S P Ö L
U
+
fÖ
N N L