Product Overview

14 Copyright 2008 TAC All Rights Reserved. F-24789-7
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-21).
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-16.
Spring returns open
on loss of power
Open
Close
ExtendRetract
Damper Shaft
Figure-14 Dampers Open When Actuator Retracts
(Spring-Returns Open on Power Loss).
Spring returns closed
on loss of power
Open
Close
Extend Retract
Damper Shaft
Figure-15 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)
Figure-16 Actuator/Damper Mounting.