RT-SVX056D-GB
41
Customer option module
Economizer control
Demand Control Ventilation
The 10 I/O for economizer allow 4 strategies for Demand
control ventilation
#1: Fixed Ventilation (design ventilation)
It is based on design occupancy of the zone.
Occupied standby setpoint = 0.6L/s per m
2
(ASHRAE62.1) x Surface
Occupied setpoint = 4.72L/s per person
(ASHRAE62.1) x DesignOccupants# + Occupied
standby setpoint
#2: Occupancy-based ventilation – requires an
occupancy sensor
During occupied hours, depending on
occupancy sensor, we can switch between
2 setpoints
no people detected: Occupied Standby Setpoint
= 0.6L/s per m
2
x Surface
people detected: Occupied Setpoint = 4.72L/s
per person x DesignOccupants# + Occupied
Standby Setpoint
#3: CO2-based ventilation – requires a space CO2 level
information (sensor or BAS)
Modulates between Occupied setpoint and Occupied
Standby setpoint with Damper control.
Emergency Ventilation override
Three possible external requests, with following priority
order
1. Pressurize
2. Purge
3. Exhaust
When those override modes are activated, heating or
cooling are turned OFF. If they were ON, the emergency
stop mode is used.
Those override modes can be activated through local
request or BAS.
Emergency override command:
1. Normal
2. Pressurize
3. Depressurize
4. Purge
5. Shutdown
6. Fire
Table 6 - Override mode
Override mode
Pressurize
Purge
Exhaust
(Depressurize)
Smoke Detector
Shutdown
(Emergency Stop/
Firestat)
ID Fan
ON - Full Speed
ON - Full Speed
OFF
OFF
OFF
OA Damper
Open 100%
Open 100%
Close 0%
Open 100%
Close 0%
Exhaust Fan
OFF
ON
ON
OFF
OFF
Heat/Cool
OFF
OFF
OFF
OFF
OFF
Opening Airflow Damper
The mechanical opening of the damper is managed by
the actuator which is adjusted by Trane controller. In
Free cooling mode, fresh air flow can be adjusted thru
optional terminal but the maximum opening airflow
damper minimum position is set at 50% by default
and maximum factory setting is 95%. At installation,
Minimum Fresh Air Percentage during occupied time
have to be adjusted.