Trane Tracer VV550 User Manual

56 CNT-SVX17G-EN
Sequence of Operations
Arbitration of ventilation requirements
Figure 2 shows the arbitration of reported effective ventilation setpoints.
Figure 2. Arbitration of reported effective ventilation setpoint
Effective ventilation setpoint =
configured ventilation setpoint
(see Note 1)
Effective ventilation setpoint = 0
Effective ventilation setpoint =
communicated ventilation setpoint
(limited by configured ventilation
setpoint and configured standby
ventilation setpoint) (see Note 1)
Is ventilation
enforced?
Is communicated ventilation
setpoint valid?
Is communicated
space CO2 present?
Occupied
Standby?
Communicated ventilation
setup replaces configured
ventilation setup and is
limited by configured
ventilation setpoint for all
downstream operations
Status:
Occupied cooling
Occupied heating
Occupied standby cooling
Occupied standby heating
Space temperature failure
Is communicated ventilation
setpoint valid?
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
A
B
CD
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 r D, the effective ventilation setpoint = B.
Effective
ventilation
setpoint (see Note 2)
Effective ventilation setpoint =
configured standby ventilation setpoint
(see Note 1)
No
No (most likely occupied)
No
No (ASHRAE)
No
Yes
Yes
Yes
Yes (DCV)
Yes

Trane Tracer VV550 Specifications

General

Brand	Trane
Model	Tracer VV550
Category	Controller
Language	English