Viessmann Vitocrossal 300 CU3A Application Manual page 36

Vitocrossal CU3A
Zone Control Wizard—2 ZC—ZC1 Setpoint Demand with ZC2 Weather Compensated
This application features two heat circuits which operate at different temperatures. This particular drawing portrays
ZC1 as a low temperature circuit and the air handler as a mid/high temperature circuit, ZC2. Although there are
many different configurations, the setup below will operate ZC1 as an on/off function where an outdoor reset
curve will be enabled during a thermostat call. The ZC2 air handler will operate on a constant temperature setpoint
also referred to as a Fixed Setpoint. It is important to provide a method of protecting the ZC1 from high water
temperatures when the air handler is operating, so don't forget to include the thermostatic mixing valve. The ZC1
shown here is configured with pump output 28/20 and the ZC2 call will bring on the 157 plug connected pump
should there be a call for heat.
Select the correct number of Zone Circuit
connections with respect to the number of
thermostats connected to the DE connections.
Press OK
This application is based on a Weather
Compensated, arrow down and press OK to
confirm setting.
The Slope and Shift settings can be adjusted to allow a heating curve to be set.
When there is a zone heat demand, the calculated set point will be used as long
as the demand is present. Arrow up or down to move to the shift setting from slope.
Making an adjustment of either setting will graphically indicate how the heating
curve moves.
Once the settings have been made, press OK to
continue. These settings can be easily adjusted
later on should they need to be changed.
The ZC1 pump for this particular application is the
28/20 pump. Pressing OK continues to the ZC2 circuit,
The Zone Circuit 2 is to be set for Fixed Setpoint
temperature demand. Press OK to select and
continue.The next screen allows for a set point
adjustment of the zone target temperature
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The final step in this application configuration is
to select the associated pump for ZC2. Select the 157 Output
and press OK. If the pump is controlled by the air handler,
select "No Output".
Following will be the output summary and the
start up configuration is finished