Viessmann Vitocal 350-A Installation And Service Instructions Manual page 210

Connection and wiring diagrams
Overview of the PCBs and connection options
Pos. Function
w¢I Cylinder primary pump,
two-way shut-off valve (for
installation position see
page 39)
w¢O Control of immersion
heater EHE for DHW cylin-
der (only with additional
contactor)
or
Circulation pump for DHW
reheating (external heat
source)
PCB 2, terminal strip X7
Pos. Function
wYP External heat source con-
trol/demand
N/A
wYQ Control of instantaneous
heating water heater,
stage 2
wYE Control of the mixer motor
for the external heat
source, signal OPEN
wYR Control of the mixer motor
for the external heat
source, signal CLOSED
wYT
Heating circuit pump, heat-
ing circuit without mixer
(A1)
210
Explanation
Switch cylinder primary pump and
two-way shut-off valve in parallel
■ Max. output: 130 W
On-site connection
The connection can be used to
control an immersion heater EHE
in the DHW cylinder if the external
heat source is not used for DHW
heating.
On-site connection
Explanation
Zero volt N/O contact:
■ Closed: demand
■ Open: No demand
■ Breaking capacity 250 V~,
4(2) A
■ Not suitable for safety LV (≤
42 V~)
On-site connection
N/A
Accessories
■ Output 10 W
On-site connection
■ 230 V
On-site connection
■ 230 V
On-site connection
■ This pump is installed in addition
to the secondary pump if a heat-
ing water buffer cylinder is
installed.
■ Max. output: 100 W
On-site connection
(cont.)
Terminals
2X8.12
2X8.13
Terminals
2X7.1
2X7.2
2X7.3
2X7.4
2X7.5
2X7.7
2X7.8
2X7.9