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Document No. 129-125
Installation Instructions
Rev. 5, June, 2000
Installation, Continued
Figure 1. Span Adjustment.
Shown at Span Setting 8.
For spans of 11 or 12 psig (76 or 83 kPa)
1.
Move the span adjustment tab to the 10 setting
on the feedback arm. Follow steps 2 and 3 for
Setting the span .
2.
Move the feedback spring one hole away from
the standard location for a span of 11 psig
(76 kPa) and two holes away from the standard
spring location for a 12 psig (83 kPa) span. See
Figure 1 .
Follow steps 4 and 5 for Setting the span .
3.
Adjusting the start point (see Figure 2 )
The positioning relay can be adjusted to start
actuator movement at pressures between 3 and 10
psig (21 and 69 kPa).
1.
Remove the relay cover.
2.
Attach tubing with a pressure gauge and
squeeze bulb to the "T" port. Supply air should
be attached to the "S" port. The "M" port should
be attached to the connector on the actuator.
3.
Using the squeeze bulb, apply pressure to the
relay. Watch the valve stem or actuator shaft to
see when it begins to move. Check the
pressure gauge; this is the start point pressure.
4.
If this is not the desired start point pressure,
turn the start point adjustment nut ( Figure 2 )
clockwise to increase the start point pressure
and counterclockwise to decrease the pressure.
5.
Repeat steps 3 and 4 until the stem or shaft
begins to move at the desired pressure.
Page 2 of 5
Figure 2. Start Point Adjustment
Adjusting the span
1.
Using the squeeze bulb, apply pressure to the
relay. Note the pressure at which the stem or
shaft begin to move.
2.
Continue to apply pressure until the stem or
shaft completes its full stroke. Note the
pressure.
3.
The difference between the two pressures is
the span.
4.
If the span is not the desired span, move the
spring guide to a higher reference number to
increase the span or lower number to decrease
the span. See Figure 1 and Setting the Span .
5.
Repeat steps 1 through 4 until you get the
desired span.
If you have moved the spring guide, adjust the
6.
spring arm so that the spring is parallel to the
stem or shaft.
Check the feedback spring. There should be no
7.
slack nor stretch in it. Adjust the wing nuts and
adjustment nut, if necessary.
8.
Fasten the relay cover. Fill in the information on
the calibration label.
9.
Attach the air line from the controller to the "T"
port.
Siemens Building Technologies, Inc.
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