Logix 3400MD Digital Positioner FCD LGENIM3404-00 – 9/09
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9. Tighten the nut on the take-off arm. The socket head screw of the
take-off arm must be tight, about 40 in-lb.
NOTE:
If the take-off arm slips, the positioner must be recalibrated.
0
WARNING:
Failure to follow this procedure will result in
positioner and/or linkage damage. Check air-action and
stroke carefully before lockdown of take-off arm to spline
lever adapter.
5.3 Optional Valtek Rotary
Mounting Procedure (See Figure 5)
The optional rotary mounting applies to Valtek valve/actuator assem-
blies that are equipped with mounted volume tanks or handwheels. The
optional mounting uses a four-bar linkage coupled to the valve shaft.
The following tools are required:
•
3
⁄
8
" open-end wrench
•
7
⁄
16
" open-end wrench
• 1/2" open-end wrench
1. Using a 1/2" open-end wrench and two
5
⁄
16
-18 x 1/2" bolts, attach
bracket to actuator transfer case pads. Leave bracket loose to allow
for adjustment.
2. Using four 1/4-20 x 1/2" bolts and a
7
⁄
16
" open-end wrench, fasten
positioner to universal bracket, using the four-hole pattern that
locates the positioner the farthest from the valve. Rotate positioner
90 degrees from normal so gauges are facing upward.
3. Attach follower arm to positioner feedback shaft, using the star
washer and 10-32 nut.
4. Attach tripper and tripper clamp to valve shaft using two 1/4-20
bolts and two 1/4-20 locknuts. Leave tripper loose on shaft until final
adjustment.
5. Thread ball joint linkage end to tripper and tighten (thread locking
compound such as Loctite is recommended to prevent back
threading). Adjust the length of tie rod so follower arm and tripper
rotate parallel to each other (the rod must be cut to the desired
length). Connect the other ball joint end to follower arm using a star
washer and a 10-32 nut.
6. Tighten bracket and tripper bolting.
7. Check for proper operation, note direction of rotation.
0
WARNING:
If rotating in wrong direction, serious damage
will occur to the positioner and/or linkage. Check air action
and stroke direction carefully before initiating operation.
5.4 NAMUR Mounting Option
Logix 3200MD is available with a NAMUR output shaft and mounts on
an actuator using the ISO F05 holes. Proper alignment of the positioner
shaft to the actuator shaft is very important since improper alignment
can cause excess wear and friction to the positioner.
5.5 Tubing Positioner to Actuator
The Logix 3400MD
digital positioner is insensitive to supply pressure
changes and can handle supply pressures from 30 to 150 psig. A
supply regulator is recommended if the customer will be using the
diagnostic features of the Logix 3400MD
but is not required. In applica-
tions where the supply pressure is higher than the maximum actuator
pressure rating a supply regulator is required to lower the pressure
to the actuator’s maximum rating (not to be confused with operating
range). An air filter is highly recommended for all applications where
dirty air is a possibility.
NOTE:
The air supply must conform to ISA Standard ISA 7.0.01 (a dew
point at least 18°F below ambient temperature, particle size below five
microns—one micron recommended—and oil content not to exceed
one part per million).
Air-to-open and air-to-close are determined by the actuator tubing, not
the software. When air action selection is made during configuration,
that selection tells the control which way the actuator has been tubed.
The top output port is called
Output 1
. It should be tubed to the side
of the actuator that must receive air to begin the correct action on
increasing signal. Verify that tubing is correct prior to a stroke calibra-
tion. Proper tubing orientation is critical for the positioner to function
correctly and have the proper failure mode. Refer to Figure 1 and follow
the instructions below:
Linear Double-acting Actuators
For a linear air-to-open actuator, the Output 1 port of the positioner
manifold is tubed to the bottom side of the actuator. The Output
2 port of the positioner manifold is tubed to the top side of the
actuator. For a linear air-to-close actuator the above configuration is
reversed.
Rotary Double-acting Actuators
For a rotary actuator, the Output 1 port of the positioner manifold
is tubed to the bottom side of the actuator. The Output 2 port of
the positioner manifold is tubed to the top side of the actuator. This
tubing convention is followed regardless of air action. On rotary
actuators, the transfer case orientation determines the air action.
Single-acting Actuators
For single-acting actuators, the Output 1 port is always tubed to the
pneumatic side of the actuator regardless of air action. The Output 2
port must be plugged.
