Viessmann Vitocal 350-A Installation And Service Instructions Manual page 209

Overview of the PCBs and connection options
PCB 2, terminal strip X8
Pos. Function
End of safety chain
Compressor control via
EEV controller (refrigerant
circuit control)
N/A
Fan control
w¢E Secondary pump
w¢R Control of instantaneous
heating water heater,
stage 1
w¢T Control of the mixer motor,
heating circuit M2, signal
OPEN
w¢Z Control of the mixer motor,
heating circuit M2, signal
CLOSED
w¢U Heating circuit pump of the
heating circuit with mixer
M2
Connection and wiring diagrams
Explanation
'Live' in case of fault-free safety
chain
■ Heat demand: Contact closed,
2X8.2 is 'live'
■ If the compressor will not start,
check whether it has been ena-
bled by the EEV controller (own
relay on EEV PCB, see
page 217)
Internal connection
N/A
Internal connection
■ In systems without a heating
water buffer cylinder, no other
heating circuit pump is required
(see terminal 2X7.9)
■ Max. output: 130 W
On-site connection
Accessories
■ Output 10 W
On-site connection
■ 230 V
On-site connection
■ 230 V
On-site connection
■ Max. output: 100 W
On-site connection
(cont.)
Terminals
2X8.1
2X8.1
2X8.2
2X8.3
2X8.4
2X8.5
2X8.7
2X8.8
2X8.9
2X8.10
2X8.11
209