Viessmann VITOLADENS 300-W Installation And Service Instructions Manual page 118

Function description
External extensions (accessories)
Digital data inputs DE1 to DE3
The following functions can be connec-
ted alternatively:
■ External operating program change-
over for each heating circuit
■ External blocking
■ External blocking with fault message
input
■ External demand with minimum boiler
water temperature
■ Fault message input
■ Brief operation of the DHW circulation
pump
External contacts must be floating.
When connecting external contacts,
observe the requirements of safety cat-
egory II, i.e. 8.0 mm air and creep path
or 2.0 mm insulation thickness to 'live'
parts.
Input function assignment
Select the input functions by means of
codes in the "General" group at the
boiler control unit:
■ DE1: Coding address 3A
■ DE2: Coding address 3b
■ DE3: Coding address 3C
Assigning the operating program
changeover function to the heating
circuits
Select the operating program change-
over function for the respective heating
circuit via coding address d8 in the
"Heating circuit" group at the boiler
control unit:
■ Changeover via input DE1: Code d8:1
■ Changeover via input DE2: Code d8:2
■ Changeover via input DE3: Code d8:3
118
(cont.)
The effect of the operating program
changeover is selected via coding
address d5 in the "Heating circuit"
group.
The duration of the changeover is set via
coding address F2 in the "Heating cir-
cuit" group.
Effect of the external blocking func-
tion on the pumps
The effect on the internal circulation
pump is selected in coding address 3E
in the "General" group.
The effect on the respective heating cir-
cuit pump is selected in coding address
d6 in the "Heating circuit" group.
The effect on a circulation pump for cyl-
inder heating is selected in coding
address 5E in the "DHW" group.
Effect of the external demand func-
tion on the pumps
The effect on the internal circulation
pump is selected in coding address 3F in
the "General" group.
The effect on the relevant heating circuit
pump is selected in coding address d7 in
the "Heating circuit" group.
The effect on a circulation pump for cyl-
inder heating is selected in coding
address 5F in the "DHW" 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 pushbutton. The runtime
is adjusted via coding address "3d" in the
"General" group.