User Guide

24 © Copyright 2008 TAC All Rights Reserved. F-26645-7
Minimum Damper Positioning
Note: When using the AM-689 rotation limiter with an MS4X-7073 or MS4X-7153 actuator
to provide a minimum damper position, the short shaft mounting procedure must be used to
mount the actuator.
Caution:
• The AM-689 rotation limiter should not be used with an MS4X-7073 or MS4X-7153
actuator to provide a minimum damper position in outdoor air damper applications.
The rotation limiter prevents the damper from reaching the full-closed position. This
may cause coils to freeze or may cause other system problems to occur.
1. Position the damper to its minimum position by providing the appropriate control signal to
the MS4X-7073 or MS4X-7153.
2. Place the position indicator onto the actuator spline in the approximate position shown
in Figure-7. Fasten it with the retaining clip.
3. Place the AM-689 rotation limiter on the actuator so that it either makes contact with, or
is as close as possible to, the edge of the indicator. See Figure-8.
4. Make sure that the locating teeth are engaged into the locating holes on the actuator. If
all of the mounting teeth do not align with the holes, the mounting location of the
indicator to the spline may have to be moved. The rotation limiter would then be
remounted to get the best position match of both parts.
5. Find the cross-hair location through the slot of the rotation limiter. This is the mounting
location for the retaining screw.
6. Pierce through the label material to allow easy fastening of the retaining screw.
7. Fasten the rotation limiter to the actuator using the self tapping screw provided.
8. Test the damper operation by applying power and the required control signal. Re-adjust
if necessary.
RL
20
10
0
-5
30
40
50
60
7
0
80
9
0
20
10
0
-5
30
40
50
60
7
0
80
9
0
Figure-7 Installing the Position Indicator.
RL
20
10
0
-5
30
40
50
60
7
0
80
9
0
20
10
0
-5
30
40
50
60
7
0
80
9
0
Figure-8 Positioning the Rotation Limiter.