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71
Installation Instructions
Mechanical Installation
Determining Torque Loading and Actuator Sizing
Damper torque loadings, used in selecting the correct size actuator, should be
provided by the damper manufacturer. If this information is not available, the
following general selection guidelines can be used.
Damper Type
Torque Loading
Opposed blade, without edge seals,
for non-tight close-off applications
3 in-lb/sq. ft.
Parallel blade, without edge seals,
for non-tight close-off applications
4 in-lb/sq. ft.
Opposed blade, with edge seals,
for tight close-off applications
5 in-lb/sq. ft.
Parallel blade, with edge seals,
for tight close-off applications
7 in-lb/sq. ft.
The above torque loadings will work for most applications with 1000 FPM face
velocity. For applications between this criteria and 2500 FPM, the torque loading
should be increased by a multiplier of 1.5. If the application calls for higher criteria
up to 3000 FPM, use a multiplier of 2.0.
Torque Loading Chart
Torque Loading Chart
0
10
20
30
40
50
60
70
80
90
100
2
3
4
5
6
7
8
9
10
Torque Loading (in-lb/ sq. ft.)
Damper Area (sq. ft.
)
General Information
Belimo actuators should be mounted indoors in a dry, relatively clean environment
free from corrosive fumes. If the actuator is to be mounted outdoors, a protective
enclosure must be used to shield the actuator.
For new construction work,
order dampers with extended shafts
. Instruct the
installing contractor to allow space for mounting and service of the Belimo actuator on
the shaft. The damper shaft must extend at least 3 1/2” from the duct. If the shaft
extends less than 3-1/2” or if an obstruction blocks access, the shaft can be extended
with the AV 8-25 shaft extension accessory or the actuator may be mounted in its short
shaft configuration.
Mechanical Operation
The actuator is mounted directly to a damper shaft up to 1.05” in diameter by
means of its universal clamp. A crank arm and several mounting brackets are
available for applications where the actuator cannot be direct coupled to the damper
shaft. The AFB, AFX series actuators provide true spring return operation for reliable
fail-safe application and positive close-off on air tight dampers. The spring return
system provides constant torque to the damper with, and without, power applied to
the actuator. The AFB…-S, AFX…-S versions are provided with two built-in
auxiliary switches. These SPDT switches are provided for safety interfacing or
signaling, for example, for fan start-up. The switching function at the fail-safe position
is fixed at +10°, the other switch function is adjustable b10° to +90°.
Automatic Airtight Dampers/Manual Override
The AFB, AFX series provides 95° of rotation and is provided with a graduated
position indicator showing 0° to 95°.
The AFB, AFX has a unique built in manual positioning mechanism which allows the
setting of any damper position within its 95° of rotation. A pre-tensioned spring
automatically tightens the damper when power is applied to the actuator,
compensating for damper seal deterioration..
The actuator is shipped at +5° (5° from full fail-safe) to provide automatic
compression against damper gaskets for tight shut-off. When power is applied, the
manual mechanism is released and the actuator drives toward the full fail-safe
position.
Standard Mounting
NOTE: The AFB, AFX…series actuator is shipped with the manual override
adjusted for a +5° position at the universal clamp (not at full fail-safe, 0°).
This allows for automatic compression of damper blade seals when the
actuator is in use, providing tight shut-off. This assumes that the damper is to
have tight shut-off at the fail-safe position. If tight close-off is desired at the
opposite direction from fail-safe, the manual override should be released so
the actuator can go to the full fail-safe position. See the manual override
instructions.
1. Manually move the damper to the fail-safe position (usually closed). If the shaft
rotated counterclockwise (
), this is a CCW installation. If the shaft rotated
)
clockwise (
), this is a CW installation. In a CCW installation, the actuator side
)
marked “CCW” faces out, while in a CW installation, the side marked “CW” faces
out. All other steps are identical.
2. The actuator is usually shipped with the universal clamp mounted to the “CCW”
side of the actuator. To test for adequate shaft length, slide the actuator over the
shaft with the side marked “CCW” (or the “CW” side if this is the side with the
clamp). If the shaft extends at least 1/8” through the clamp, mount the actuator
as follows. If not, go to the
Short Shaft Installation
section.
n
3. If the clamp is not on the correct side as determined in step #1, re-mount the
clamp as follows. If it is on the correct side, proceed to step #5. Look at the
universal clamp. If you are mounting the actuator with the “CCW” side out,
N40103 - 09/11 - Subject to change.
© Belimo
Aircontrols (USA),
Inc
.
