System diagnostics – KMC Controls BAC-8007 Installation Guide User Manual
Page 64
System diagnostics
The controller programming includes four system diagnostic indicators in the
form of BACnet value objects.
Need for higher static pressure
These diagnostic indicators or flags are monitored by other BACnet devices
connected to the same building automation system as the controller. How the
indicators are used is beyond the scope of these instructions.
Need for higher static pressure The Need Higher Static value object is set to
True (1)
when the damper is fully open and airflow cannot reach the required
setpoint value.
Need for cooler supply air The Need Cooler Supply value object is set to
True (1)
when the damper is fully open and the Cooling loop is greater than
95% for 30 minutes. The indicator changes to
False (0)
when the Cooling loop
falls below 90%.
Need for warmer supply air The Need Warmer Supply value object is set to
True (1)
when the damper is fully open and the Heating loop is greater than
95% for 30 minutes. The indicator changes to
False (0)
when the Heating loop
falls below 90%.
Need AHU start The Need AHU Start value object is set to
True (1)
for any
of the following conditions.
The system mode is
Unoccupied
and the Cooling loop or the Heating
loop reaches 100%.
The system mode is
Occupied
.
The system mode is
Standby
.
The Need for AHU Start object changes to
False (0)
when both loops drop
below 5%.
Section 7: Sequences of operation
SimplyVAV
64
Revision E