User Manual

Sequence of Operation
Air Quality Management
21
Siemens Industry, Inc.
Application Note, App 14900
140-1231
2020-02-11
Air Quality Management
If measured CO2 exceeds the setpoint (1000 ppm) by 200 ppm, after a proof timer of
60 seconds, or a CO2 concentration still exceeds the setpoint (1000 ppm) by 200 ppm,
the Air Quality output relay energizes and the Fresh Air icon activates. The fan
relay (G) energizes and the icon displays.
When measured CO2 falls below the setpoint (CO2Setpoint) after a proof timer of 60
seconds has expired, and the appropriate minimum run time has been met, the Air
Quality output relay de-energizes and the fan relay reverts to Normal operation.
The DCV Minimum run time is five minutes; DCV Minimum off time is five minutes.
Figure 5: Air Quality Management Operation.