Install Instructions
Table Of Contents
- Contents
- Section 1: About the controllers
- Section 2: Installing the controllers
- Section 3: Changing the room setpoint
- Section 4: Configuring the controllers
- Section 5: Balancing airflow
- Section 6: Application drawings
- Section 7: Sequences of operation
- Section 8: System integration and networking
- Appendix A: K-factors
- Index
System diagnostic indicators
The controller programming includes four system diagnostic indicators in the form of BACnet
value objects.
l NEED AHU (BV1)
l NEED COLDER SUPPLY (BV2)
l NEED MORE STATIC (BV3)
l NEED HOTTER SUPPLY (BV7)
These diagnostic indicators or flags are monitored by other BACnet devices, such as air
handling units, connected to the same building automation system as the controller. How
the indicators are used is beyond the scope of these instructions.
NEED AHU (BV1)
The Need AHU Start value object is set to TRUE (1) for any of the
following conditions.
l The system mode is UNOCCUPIED and the Cooling loop or the Heating loop is greater
than 100% for longer than 10 minutes.
l The system mode is OCCUPIED or STANDBY.
l Either of the Motion Override or Local Override variable objects are TRUE (1).
The Need for AHU Start object changes to FALSE (0) when both loops drop below 5% and
the system mod is not OCCUPIED or STANDBY and both override variable objects are
FALSE (0).
NEED COLDER SUPPLY (BV2)
The Need Colder Supply value object is set to TRUE (1)
when the system mode is STANDBY or OCCUPIED and the Cooling loop is greater than
95% for 30 minutes. The indicator changes to FALSE (0) when the Cooling loop falls below
90% or when the system mode is UNOCCUPIED.
NEED MORE STATIC (BV3)
The Need More Static value object is set to TRUE (1) when
the controller has attempted to drive the damper fully open for longer than 2 minutes 30
seconds and any of the following are TRUE (1).
l The system mode is OCCUPIED or STANDBY.
l Either of the Motion Override or Local Override variable objects are TRUE (1).
When any of these conditions are no longer true, the indicator changes to FALSE (0).
NEED HOTTER SUPPLY (BV7)
The Need Warmer Supply value object is set to TRUE
(1) when the system mode is STANDBY or OCCUPIED and the Heating loop is greater than
95% for 30 minutes. The indicator changes to FALSE (0) when the Heating loop falls below
90% or when the system mode is no longer OCCUPIED.
SimplyVAV Section 7: Sequences of operation
Revision G 57