DNS-24, DNT-T103 & DNT-T221 Application Guide
Page 18 of 43 Document Edition 4.2
Heating
Setpoint
Flow
Damper
Auxilary
Heating
Day Setpoint
Cooling
Setpoint
Day
Differential
Deadband
Proportional BandProportional Band
100%
Controller
Output
0% Temperature
200%
WITH BOX MODE = HEATING
For VAV or VVT applications, when the Box Mode is changed to heating, cooling is inverted and used
for controlling the flow damper as the first stage of heating, and the null zone is placed on the far right.
Moving from right to left, away from setpoint, the Controller Status (AV14) will modulate from 0 to
200% and sequence all the necessary heating stages. The flow damper modulates open over the first 0 to
100% and in so doing provides the first stage of heating. Any additional stages of heating modulate
open over 100 to 200%. Therefore, only when the Box Mode is in heating does the Controller Status
(AV14) modulate to a value greater than 100%, where 200% indicates all heating is fully open.
For heating lockout (in all applications), the heating output from the controller is forced to 0%, and the
heating icon is disabled on the LCD. Similarly, for cooling lockout, the cooling output from the
controller is forced to 0%, and the cooling icon is disabled on the LCD. As a result, the Controller
Status (AV14) will be limited accordingly.
3. CONTROLLER STAGING
Each controller can be split up into as many as three stages. The number of stages is automatically
determined by the output configuration associated with the selected application control strategy. The
controller stages are cascaded.
Cooling
Controller
C1
C2
C3
0%
100%
0%
100%
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