Connection Central Fault Massage Facility; External Demand Via Switching Contact - Viessmann VITOTRONIC 300 Installation And Service Instructions Manual

Installation, Vitotronic 300-K
Connecting the Central Fault Message Facility

External Demand Via Switching Contact

Legend
A Floating contact
B Plug aVH of the control unit
Legend
A Floating contact
B Extension EA1
Codes
Plug aVD
No code required.
34
Vitotronic 300, GW5B & MW1B Installation and Service
Rated voltage
Rated current
Connection
Note: 'Live' contacts lead to short circuits or phase
failure. The external connection must be floating.
Connection options:
H Plug aVH
H Extension EA1 (accessory, see page 113)
With the contact closed, the boiler burners are started
subject to load. They heat to the set supply temperature
selected in coding address "9B" in the "General" group.
The temperature is limited by this set value and the
electronic maximum supply temperature limit (coding
address "37" in the "Cascade" group).
Extension EA1
Set "5D", "5E" or "5F" in the "General" group to 2.
120V~
max. 2 A~