External Demand Via 0-10V Input; External Blocking Via Switching Contact - Viessmann VITOTRONIC 300 Installation And Service Instructions Manual

Vitotronic 300, GW5B & MW1B Installation and Service
External Demand via 0–10V Input

External Blocking via Switching Contact

Legend
A Floating contact
B Plug aVD of the control unit
Legend
A Floating contact
B Extension EA1
Codes
Plug aVD
Set coding address "99" in the "General" group, which
the input should influence.
Installation, Vitotronic 300-K
Connection at input 0 – 10V at extension EA1
(see page 113).
0 - 1V no default set supply temperature
1V set value 50° F (10° C)
10V set value 212° F (100° C)
Observe coding address "1E" in the "General" group.
Connection options:
H Plug aVD
H Extension EA1 (accessory, see page 113)
Connection
Note: 'Live' contacts lead to short circuits or phase
failure. The external connection must be floating.
With the contact closed, the burners of all boilers will be
subject to a control shutdown.
Any connected shunt or distribution pump is stopped.
Shut-off devices are closed.
Note: The heating system has no frost protection during
blocking. The boilers are not held at the lower boiler
water temperature.
Extension EA1
Set "5D", "5E" or "5F" in the "General" group to 3 or 4.
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