Overview Of Electrical Connections - Viessmann VITOTRONIC 300 Installation And Service Instructions Manual

Vitotronic 300, GW5B & MW1B Installation and Service

Overview of Electrical Connections

Main PCB low voltage
aJA Return temperature sensor T1
(optional accessory, not used)
aJB Return temperature sensor T2
(optional accessory, not used)
aVD External hook-up
aVG KM BUS participant (accessory)
aVH External hook-up
Installation, Vitotronic 300, GW5B
Note: When connecting plugs aVD and aVH, bundle the
individual cores of the cables close to the terminals.
This prevents the cores from shifting into the
neighboring voltage area.
Main PCB 120V~
sÖA1 Switching output pump
sL Boiler circuit pump
fÖ Power supply
Burner (call for heat)
fA
gÖ Central fault message
gSA1 Isolation valve
External connections, e.g. supplementary safety
aBÖ
equipment
Safety chain, floating
aBA
aBH Power supply connection for accessories
Prior to making any connections ensure that the
control control and junction box have been installed as
per the boiler Installation Instructions.
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