Connection And Wiring Diagrams Overview Of The Pcbs And Connection Options - Viessmann Vitocal 300-G Installation And Service Instructions Manual

Connection and wiring diagrams
Overview of the PCBs and connection options
Note
No accurate physical layout is shown in any of the following connection dia-
grams.
For PCB overview, see from page 61.
PCB 1: Message and safety components
q¢Q ON/OFF switch
q¢W External blocking, zero volt con-
tact
174
q¢E External demand, zero volt con-
tact