Viessmann VITOCAL 300-A Installation And Service Instructions Manual page 73

Electrical connections in the control unit
PCB 2 (main PCB)
A Coding card slot
X7 External 230 V~ connections
& DHW circulation pump
("Wtimer DHW Circ.")
& Heating circuit pump for heat-
ing circuit without mixer A1
& Type AW-O-M: Circulation
pump for cylinder heating
Type AWC-I-M: Integral three-
way diverter valve heating/
DHW heating
& Instantaneous heating water
heater control, stage 2
& Mixer motor control, external
heat source
& Central fault message
Installation sequence
(cont.)
X8 External 230 V~ connections
& Circulation pump for cylinder
reheating
& Cylinder primary pump / two-
way shut-off valve
& Heating circuit pump heating
circuit with mixer M2
& Mixer motor control, heating
circuit M2
& Secondary pump
&
Instantaneous heating water
heater control, stage 1
X9 Internal connections
X10 Internal connections
X11 Terminals
X15 Programming unit connection
X16 Internal connections
73