Viessmann VITOCAL 300-G Installation And Service Instructions Manual page 223

Overview of the PCBs and connection options
Plug Terminals Function
sYS
212.1
212.2
212.3
sXÖ 220.1
220.2
sXS 222.1
222.2
222.3
222.4
sXD 223.1
223.2
AC function control
"active cooling"
Heating circuit pump
for heating circuit with-
out mixer (A1)
DHW circulation pump ■ Max. output: 50 W
Compressor control
stage 2 (type BWS) via
EEV controller (refrig-
erant circuit control)
Mixer motor control for
external heat source
Signal Mixer CLOSED
Mixer motor control for
external heat source
Signal Mixer OPEN
External heat source
control
Central fault message
Connection and wiring diagrams
(cont.)
Explanation
■ Max. output: 10 W
■ Voltage: 230 V~
Create circuit on site
■ This pump is installed in addition
to the secondary pump if a heat-
ing water buffer cylinder is instal-
led.
■ Max. output: 100 W
Connect on site
■ Voltage: 230 V~
Connect on site
■ Heat demand: Contact closed,
220.2 is 'live'
■ If the compressor will not start,
check whether it has been ena-
bled by the EEV controller stage
2 (own relay on EEV PCB stage
2)
Factory connection
■ Voltage: 230 V~
Connect on site
■ Voltage: 230 V~
Connect on site
Zero volt contact:
■ Contact load 230 V/50 Hz,
4(2) A
Connect on site
Zero volt contact:
■ Closed: Fault
■ Open: No fault
■ Contact load 230 V/50 Hz,
4(2) A
■ Not suitable for safety LV
Connect on site
223