Viessmann VITOCAL 350-A, Installation And Service Instructions Manual

Page: 209 / 256

209
PCB 2, terminal strip X8
Pos.
Function Explanation Terminals
End of safety chain 'Live' in case of fault-free safety
chain 2X8.1
Compressor control via
EEV controller (refrigerant
circuit control) ■ 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
2X8.1
2X8.2
N/A N/A 2X8.3
2X8.4
Fan control Internal connection 2X8.5
w¢E Secondary pump ■ 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
2X8.7
w¢R Control of instantaneous
heating water heater,
stage 1 Accessories
■ Output 10 W
On-site connection 2X8.8
w¢T Control of the mixer motor,
heating circuit M2, signal
OPEN ■ 230 V
On-site connection 2X8.9
w¢Z Control of the mixer motor,
heating circuit M2, signal
CLOSED ■ 230 V
On-site connection 2X8.10
w¢U Heating circuit pump of the
heating circuit with mixer
M2 ■ Max. output: 100 W
On-site connection 2X8.11
Connection and wiring diagrams
Overview of the PCBs and connection options
(cont.)
5414 828 GB
Service