ABB FBVi-2U4-4T - TEST AND BALANCE

FBVi-2U4-4T | Control Sequence
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MAN0148 rev 5
TEST AND BALANCE
You can balance the box using Aeroᴮᵀ (see MAN0144 Aero ᴮᵀ VAV Phone App ), or CXproᴴᴰ (see MAN0133
CXpro ᴴᴰ).
A point has been setup to allow test and balance commands to be sent to individual boxes, or groups of
boxes, to set the primary air damper to max Flowrate, deadband Flowrate, fully open, fully closed, etc.
These commands may be used to calibrate the airflow sensor and balance the boxes. Before balancing
the box, the unit should be in occupied mode, and the HVACmodeCmd (A287) should be in Auto.
SETTING INITIAL BOX SIZE
Before balancing is available, an initial box size can be set to generate a starting K-factor. After balancing,
this initial K-factor will be replaced with the balanced K-factor.
Set box size with the boxSize (A144) analog setpoint:
• 1 = 4" Box
• 2 = 5" Box
• 3 = 6" Box
• 4 = 8" Box
• 5 = 10" Box
• 6 = 12" Box
• 7 = 14" Box
• 8 = 16" Box
ZEROING AIRFLOW SENSOR
The FBVI-2U4-4T comes from the factory with the airflow sensor zeroed. To compensate for possible air
leakage around the damper, users can zero the airflow sensor in the field. To zero the airflow sensor,
users will need to do the following:
1. Drive damper to the closed position by setting flowOverride (A258) to 6 (fullClosed).
2. After the damper has fully shut, set zeroAirflow (D227) to ON. After 10 sec. it will record the offset.
After 10 seconds zeroAirflow (D227) will be automatically set back to off and the airflow sensor will now
be zeroed. Be sure to set flowOverride (A258) to 0 (Auto) when finished with this step. The airflow
offset calculation can be read at airflowOffset (A3).
AIRFLOW CALIBRATION PROCEDURE
K-factor settings can be manually entered:
1. For Single Point or the High K-factor, set balanceModeHi (D204) to FALSE and enter the K-factor
in the KFactorFlowHI (A214) analog setpoint.
2. For the Low K-factor, set balanceModeLo (D45) to FALSE and enter the K-factor in the
KFactorFlowLO (A245) analog setpoint.
3. The K-Factor that is used for flow will be displayed at activeKfactor (A293)
4. The current flow will be displayed at activeAirflow (A250)
5. To reset the K-factor back to the initial box size K-factor, enter 0 when manually entering both
low and high K-factors.