External Demand Via Switching Contact; External Demand Via 0 - 10V Input - Viessmann VITOTRONIC300 Installation And Service Instructions Manual

Installation Sequence

External Demand via Switching Contact

Connection
Note: 'Live' contacts lead to short circuits or phase
failure. The external connection must be floating.
Plug aVH
Legend
A Floating contact
B Plug aVH of the control unit
When the contact is closed, the burner is operated subject to load. The boiler water is heated to the value set
in the coding address "9b" in the "General" group.
The boiler water temperature is limited by this set value and the electronic maximum limit (coding address "06"
in the "Boiler" group).
Codes
Plug aVH
No code required.
External Demand via 0 – 10V Input
46
Vitotronic 300, GW2B Installation and Service
Optional Connections:
H Plug aVH
H Extension EA1 (accessory, see page 127)
Extension EA1
Legend
A Floating contact
B Extension EA1
Extension EA1
Set "5d", "5E" or "5F" in the "General" group to 2.
Connection to input 0 – 10V at extension EA1
(see page 127).
Ensure DC separation between the negative pole and the
ground conductor of the on-site voltage source.
0 - 1V No default set boiler water temperature
1V set value 50°F (10°C)
10V set value 212°F (100°C)
Observe coding address "1E" in the "General" group.
Optional temperature range from 86 to 248°F
(30 to 120°C):
0 - 1V no default set supply temperature
1V 86°F (30°C)
10V 248°F (120°C)