Product Overview

F-24788-5 © Copyright 2008 TAC All Rights Reserved. 11
d. Consider the damper rod length when positioning the actuator in relation to the damper. A damper rod that is too long is
not rigid enough to provide good control, while a damper rod that is too short makes adjustment difficult.
2. Position the actuator on the duct and mark the location of the mounting holes, using the actuator mounting bracket as a
template (refer to Figure-18).
3. Drill or punch the mounting holes in the duct for the appropriate 1/4" (6 mm) diameter screws or bolts. The actuator must be
mounted firmly enough to prevent excessive actuator movement under normal damper loading. If there is excessive actuator
movement, the damper may not fully open or close.
4. Mount a ball joint connector in the slot on the damper crank arm. To achieve 90° of damper rotation, position the connector
1-1/2" (38 mm) from the centerline of the shaft hole on the crank arm. For 60° of damper rotation, position the connector 2"
(50 mm) from the shaft hole centerline. Typically, 60° to 70° of rotation (maximum is 90°) is sufficient to permit almost
maximum air flow through the dampers. Refer to Figure-15.
5. Rotate the damper to its open position. Install and secure the damper crank arm (with ball joint connector) to the damper
shaft, positioning the crank arm as follows (refer to Figure-15):
Spring returns open
on loss of power
Open
Close
ExtendRetract
Damper Shaft
Figure-13 Dampers Open When Actuator Retracts (Spring-Returns Open on Power Loss).
Spring returns open
on loss of power
Open
Close
Extend Retract
Damper Shaft
Figure-14 Dampers Open When Actuator Extends
(Spring-Returns Closed on Power Loss).
Mounting
Points
Actuator
Crank Arm
Mid-Stroke Position
Angle from Mid-Stroke
Position (See Table)
Position of Linkage
Connector (See Table)
Damper
Shaft
Damper
Crank Arm
Linkage
Connectors
Damper
Rod
Mounting
Points
Required
Damper
Rotation
Angle
from
Mid-Stroke
Position
Position of
Linkage
Connector
60
90
30
45
2" (50 mm)
1-1/2" (38 mm)
0
0
0
0
Figure-15 Actuator/Damper Mounting.