Viessmann Vitotronic 200 Installation And Service Instructions For Contractors page 120

Function description
EA1 extension (accessories)
Fig. 51
DE1 Digital input 1
DE2 Digital input 2
DE3 Digital input 3
F1 Fuse
0 10V 0 to 10 V input
–
Digital data inputs DE1 to DE3
The following functions can alternatively be connected:
■ External operating program changeover for each
heating circuit
External blocking
■
External blocking with fault message input
■
■ External demand with minimum flow temperature
■ Fault message input
■ Brief operation of the DHW circulation pump
External contacts must be potential-free. When con-
necting external contacts, observe the requirements of
protection class II: 8.0 mm air and creep path or
2.0 mm insulation thickness to live parts.
Input function assignment
Select the input functions via the parameters in the
"General" group at the boiler control unit:
■ DE1: Parameter "42"
■ DE2: Parameter "43"
■ DE3: Parameter "44"
120
Power supply
fÖ
A Power supply for additional accessories
fÖ
Central fault message/feed pump/DHW circula-
aBJ
tion pump (potential-free)
KM-BUS
aVG
Assigning the operating program changeover
function to the heating circuits
Select the operating program changeover function for
the relevant heating circuit via parameter "20" in the
"Heating circuit" group at the boiler control unit:
■ Changeover via input DE1: Parameter "20:1"
■ Changeover via input DE2: Parameter "20:2"
■ Changeover via input DE3: Parameter "20:3"
The effect of the operating program changeover is
selected via parameter "1F" in the "Heating circuit"
group.
The duration of the changeover is set via parameter
"24" in the "Heating circuit" group.
DHW circulation pump runtime for brief operation
The DHW circulation pump is started by closing the
contact at DE1, DE2 or DE3 by means of a pushbut-
ton. The runtime is set at parameter "47" in the "Gen-
eral" group.