Greenheck RL147 Positioner Relay - Manual (Page 4)

Technical Instruction Landis & Gyr, Inc.
RL 147-2 Page 4
CALIBRATION
Complete calibration instructions are included with each
positioning relay.
1. Check that you have the correct feedback spring(s)
attached.
2. Identify the desired operating span and the start point
pressure.
NOTE: In some cases, the actuator stem travel or stoke
is not identical to the nominal value of the relay feedback
spring. Refer to Calculating the Span Setting on page 5
to determine the span setting on the feedback arm.
Figure 4. Span Adjustment.
Shown at Span Setting 8.
Setting the Span. Refer to Figure 4.
The positioning relay operating span can be set for spans of
3 psig through 12 psig (21 kPa to 83 kPa).
For spans of 3 psig through 10 psig (21 to 69 kPa)
1. Check that the feedback spring is attached to the spring
guide in the hole across from the span adjustment screw.
This is identified as the standard location in Figure 4.
2. With a screwdriver, loosen the span adjustment screw.
Move the spring guide on the feedback arm until the span
adjustment tab is at the desired span setting reference
number.
NOTE: The line to the left of the number is the setting.
3. Tighten the span adjustment screw.
4. The feedback spring must be parallel to the actuator shaft
or valve stem. Use open end wrenches to loosen the hex
nuts holding the spring arm in position on the shaft or
stem. Align the feedback spring and tighten the hex nuts.
5. The feedback spring should have no slack or no stretch in
it. Adjust the wing nuts and adjustment nut, if necessary
For spans of 11 psig 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 above.
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. Refer to Figure 4.
3. Follow steps 4 and 5 above.
Adjusting the Start Point. Refer to Figure 6.
The positioning relay can be adjusted to start actuator move-
ment 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 tot he 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 your pressure gauge; this is your
start point pressure.
4. If this is not the desired start point pressure, turn the start
point adjustment nut (Figure 5) 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.
Figure 5. 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 begins 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. Refer to Figure 4.
5. Repeat steps 1 through 4 until you get the desired span.