Trane Tracer VV550 Installation, Operation And Maintenance Manual page 56

Sequence of Operations
Arbitration of ventilation requirements
Figure 2
Figure 2. Arbitration of reported effective ventilation setpoint
Effective ventilation setpoint = 0
No
Is ventilation
enforced?
Status:
Occupied cooling
Occupied heating
Occupied standby cooling
Occupied standby heating
Space temperature failure
Note 1: If the unit enters pressure dependent (PD) mode, the value of the effective ventilation setpoint
remains at its current value, regardless of other inputs, until pressure independent (PI) mode is
re-established. This will lower the impact of system disturbance, since the box cannot play an
active role in ventilation without an accurate airflow reading.
Note 2: If C
56
shows the arbitration of reported effective ventilation setpoints.
Effective ventilation setpoint =
configured ventilation setpoint
(see Note 1)
Occupied
Standby?
Is communicated ventilation
setpoint valid?
Yes
Is communicated
space CO2 present?
Is communicated ventilation
setpoint valid?
Communicated ventilation
setup replaces configured
ventilation setup and is
limited by configured
ventilation setpoint for all
downstream operations
D, the effective ventilation setpoint = B.
No (most likely occupied)
Yes
Effective ventilation setpoint =
configured standby ventilation setpoint
(see Note 1)
No
Effective ventilation setpoint =
communicated ventilation setpoint
Yes
(limited by configured ventilation
setpoint and configured standby
ventilation setpoint) (see Note 1)
No (ASHRAE)
Yes (DCV)
No
A
Yes
B
C
A = configured ventilation setpoint or
communicated ventilation setpoint
B = configured standby ventilation
setpoint
C = configured space CO2 low limit
D = configured space CO2 high limit
Effective
ventilation
setpoint (see Note 2)
D
CNT-SVX17G-EN