32
VAV-SVX08R-EN
Unit Setup
Figure 21. Flow sensor ΔP vs. airflow delivery
0.01
0.1
1
10
10 100 1,000 10,000
Airflow (CFM)
Flow Sensor Differential Pressure (inches water)
4”
6”
8"
5”
10"
12"
14" 16"
8" x 12"
16" x 24"
Fan Motor Amperage
Reference unit submittal data and motor nameplate.
Adjusting the SCR Motor Speed
Control
In order to make units more convenient and efficient to
balance, an SCR (silicone control rectifier) is provided
as standard on all fan-powered units.
The SCR is located on the side of the fan control box.
To adjust the speed of the motor, the external knob
must be rotated either clockwise or counterclockwise
depending on the desired speed adjustment.
There is an internal potentiometer setting on the SCR
controller that can be accessed by removing the control
box cover. This internal potentiometer is set at the
factory to the specific motor voltage.
It may be necessary to adjust this in the field
depending on the building power factor.