Viessmann VITOCROSSAL 200 CI2 Series Installation Instructions Manual page 23

Vitocrossal 200 CI2 Installation
Electrical Connections
Connecting the ventilation air supply to the CAI plug
A motorized ventilation air supply (e.g. fan or ventilation
air damper) with or without feedback signal can be
connected to the CAI plug (see page 22).
When the boiler receives a call for heat, the burner does
not start until the feedback signal is present. If a device
without feedback signal is used, the jumper across R and
W must remain in place.
If a device with feedback signal is used, the jumper must
be removed.
No connected combustion air device
(jumper factory installed)
Dry contact combustion air device
feedback
24VAC combustion air device with dry
contact feed back
(continued)
External blocking via switching contact
Connection options:
Digital input DIS at the MZIO
Contact closed:
Controlled shutdown of the burners on each boiler
0-10V In connection
A target supply temperature or a target modulation value
for the boiler can be specified via the input.
The maximum supply temperature depends on the boiler.
Temperature:
0V - 0.9V = Off with boiler frost protection
1V = 10°C/50°F...
8V = 80°C/176°F...
10V = 100°C/212°F
Target modulation value:
0V - 0.9V = Off with boiler frost protection
1V = 10%...
10V = 100%
The minimum modulation level depends on the boiler.
For settings, see system configuration, "Boiler" group,
parameter 1706.0.
For parameter settings refer to the
Service Instructions.
0-10V Out connection
The current modulation level of the boiler can be read out
via the output.
0V = Off
1V = 10%...
10V = 100%
The minimum modulation level depends on the boiler.
Connecting the low loss header sensor, TS1
The sensor of the low loss header is connected to the
connection MZIO, plug TS1 of the boiler (lead boiler in
cascade applications).
Connection of plug hH
Rated current: 2 A
If high starting currents can occur, a contactor must be
connected in between.
The changeover contact can be used as a fault message
output or alternatively for a demand from an external boiler.
For settings, see system configuration, "Boiler" group
parameter 1706.0.
If "supplemental" is enabled via 1706.0 then contact 66
is closed if, despite a boiler operation in full load, the
temperature setpoint has not been reached for a certain
time. Therefore the closed contact triggers an external heat
demand to a potential external boiler.
Installation
23