Viessmann VITOTRONIC 200 Installation And Service Instructions Manual page 86

Designs
Connection and Wiring Diagrams
Main PCB 120V~
Legend
sÖ Heating circuit pump
or
Primary store system
sA Circulation pump for DHW tank heating
(accessory)
DHW circulation pump (accessory)
sK
sL Distribution pump
fÖ Power supply 120V/60 Hz
Central fault message (on site)
gÖ
3-way mixing valve, primary store system
gS
aBH Power supply connection of accessories
F Fuse
K2-K10 Relay
S1 ON/OFF switch "8"
X... Electrical interfaces
86
Vitotronic 200 and 300-K Installation and Service
(continued)