Greenheck BR Series - Counterweight Adjustment (469420) - Manual (Page 2)

Counterbalance Adjustment for BR-1X Series: Horizontal mount - vertical Up Airflow
Figures 2 & 3 show the components of a typical adjustable counterweight assembly. BR-1X series
damper with a short height may have a different style blade and a trimmed mounting bracket. The
adjustment procedure is the same for both styles of blades.
The blade edge counterweight (Figure 3) is factory set and not intended for field adjustment. For
vertical up airflow, all adjustments should be made in the adjustable counterweight assembly.
When adjusting the counterbalance weights, you will need to adjust the full open pressure and start
open pressure. Both steps will need to be done.
Adjusting full Open Pressure and Closing force
Adjusting the closing force will also affect the full open pressure. Figure 3 shows the blade in the full
open position. Additional weights can be added to increase the closing force. Removal or trimming
of weights will reduce the closing force. After adjustment, verify blades close under no airflow from
the full open position. Increase the closing force if the blades fail to close.
Adjusting Start Open Pressure
When the blades are in the closed position, the adjustable weights are used for the start open pressure of the damper.
Sliding the weights toward the blade seal will increase the start open pressure and sliding the weights toward the blade edge
counterweight will decrease pressure (Figure 4).
7) ACCESS: Suitable access must be provided for damper inspection and servicing. Where it is not possible to achieve
sufficient size access, it will be necessary to install a removable section of duct.
Pre-Installation guidelines continued....
Counterweight Adjustment Procedure for BR Models
Dampers are shipped from the factory with frame flange location and flow direction as ordered. Location and size of both
counterbalances (blade edge, adjustable blade weights) are dependent upon flow direction and damper size. The damper
must be mounted square and plumb and must operate freely before any weight adjustments are performed. Contact
Greenheck for required modifications to change flow directions.
The following instructions should be followed when attempting to adjust counterweights on the BR series damper. Figure
1, 1A, & 1B shows the typical location of the adjustable counterweight assembly. Depending on the size of the damper and
specified start open pressure, the damper may have more than one counterweight assembly.
Airflow
Adjustable
Counterweight
Assembly
Figure 1B
BR-4x series
A
ir
flo
w
Adjustable
Counterweight
Assembly
Figure 1
BR-1x series
Airflow
Adjustable
Counterweight
Assembly
Figure 1A
BR-3x series
Figure 2 Adjustable
counterweight assembly