Technical data

33
Heating system designs
System version 10 (continued)
Possible applications
The Vitocrossal 200, CM2 (lead boiler) and the Vitorond 200, VD2 (lag boiler) are operated via a Viessmann control system
with outoor reset logic, modulating boiler water temperature, and load-dependent sequential control – two-stage or
modulating burners are controlled.
Return temperature control for Vitorond can be achieved using the shunt pump and by closing the isolation valve.
Temperature sensor T1 controls the isolation valve. Temperature sensor T2 switches the shunt pump.
Due to the LON-BUS communication between controls, a boiler supply temperature is automatically set.
This temperature is based on the highest required mixing valve circuit temperature plus adjustable differential.
The connection diagram is only a
recommendation and needs to be
verified for completeness and
functionality at the installation site.
Single-phase and three-phase pumps
must be connected with field supplied
motor contactors and/or motor
starters.
5351 340 v1.4
IMPORTANT