Installation Instructions

Document No. 129-120
Installation Instructions
November 15, 2021
Siemens Industry, Inc. Page 3 of 4
Installation, Continued
Extended Shaft Mounting-Fixed Actuator
Expected Installation Time: 28 minutes
Actuator with mounting bracket: 331-2974
Clevis: 331-801
Linkage Kit: 331-958
1. Determine the application from Table 2 and
then select appropriate X and Y dimensions.
Select a rigid section of the duct, if possible,
and draw these lines on the duct.
CAUTION:
It is important to use the X and Y
dimensions from Table 2 to position
the actuator to ensure that the crank
is approximately perpendicular to the
actuator shaft at half its stroke (see
Figure 4). This will prevent the
linkage from scissoring or locking up.
Table 2. Fixed Mounted Assembly Dimensions.
Application
Dimensions in
Inches (mm)
Crank
Radius
Hole
X
Y
4-inch (102 mm)
Stroke – 90° Rotation
8-1/2
(216)
2
(51)
1
4-inch (102 mm)
Stroke – 70° Rotation
8-1/2
(216)
3
(76)
2
3-inch (76 mm)
Stroke – 90° Rotation
8
(203)
1-1/2
(38)
3
3-inch (76 mm)
Stroke – 60° Rotation
8
(203)
2-1/2
(64)
4
NOTE: Crank Radius Holes No. 5 and 6 are used
for No. 3 Pneumatic Damper Actuators
only.
Figure 4. Perpendicular Mounting.
2. Place front of actuator on X dimension line so
that the actuator shaft faces damper shaft.
Place center line of actuator over Y dimension
line (see Figure 5).
3. Thread Clevis 331-801 on to actuator shaft and
tighten against locknut. Assemble Linkage Kit
331-958 to actuator assembly (see Figure 4).
The linkage is assembled so that the damper
shaft will rotate counterclockwise as actuator
pressure increases. This is a typical normally
closed damper installation.
Figure 5. Fixed Mounted Actuator Assembly.
Frame Mounting
Expected Installation Time: 3 hours
Actuator: 331-3000, 331-3001, 331-3002, or
331-2973.
1. If the damper frame is aluminum, light gauge
sheet metal, or an unusual shape, bolt a
3/16-inch (5 mm) thick, flat piece of steel to the
frame where the mounting lug is to attach. The
mounting lug can then be welded to it.
2. Weld the mounting lug parallel and 5/16-inch
(8 mm) from the inside edge of the damper
frame and perpendicular to it (Figure 6). Weld
the lug along both sides. The lug should be as
close as possible to the corner of the damper
frame to minimize deflection. The damper
manufacturer should weld the lug.
3. If the damper frame is aluminum, light gauge
sheet metal, or an unusual shape, bolt a
3/16-inch (5-mm) thick, flat piece of steel to the
frame. Then, weld the mounting lug to the piece
of steel.