Replacing A Main Board; Replacing The Pressure Sensor Board; Replacing A Double Acting Pilot Relay - Flowserve Logix 520MD Plus Series User Instructions

16.5 Replacing a Main Board

Removal
1 Make sure the valve is bypassed or in a safe
condition.
2 Remove the outer cover.
3 Disconnect the power to the positioner.
4 Remove the inner cover. See Figure 24: Inner Cover
above.
5 Disconnect the power cable to the Main Board.
6 Disconnect the auxiliary card cable if present. See
Figure 26: Auxiliary Card on page38.
7 Disassemble the switch mechanism if present.
8 Remove the inner cover by removing the 6 retaining
screws. See Figure 24: Inner Cover.
9 Unscrew the 2 screws holding the main board in
place.
10 Gently lift the main board rotating the bottom up while
keeping the top in place.
11 Disconnect the Pressure sensor board cable, the Hall
Sensor cable, the Piezo cable and the feedback
cable. Use a small flat screwdriver to pry the locking
features and carefully separate the connector from
the main board. Be careful not to pull the cable, as
this may cause damage to the cable.
Installation
1 Place the main board on the positioner base with the
4-20 mA input on the same side as the electronic
access ports.
2 Lift the main board rotating the bottom (configuration
switches) upwards while keeping the top in place.
3 Connect the pressure sensor board cable, the hall
sensor cable, and the feedback cable. Ensure the
connector's locking features engage.
4 Place the main board on the positioner base, ensuring
the cables are clear of the feedback gears. Insert the
two retaining screws.
5 Replace the inner cover by inserting the 6 retaining
screws.
6 Calibrate.
Main
Board
Screws
Figure 27: Main Board Screws
Feedback
Pot
Connector
Piezo
Connector
Figure 28: Main Board Connectors
© Flowserve Corporation
User Instructions - Logix® 520MD+ Series Digital Positioner
16.6 Replacing the Pressure Sensor
Board
Removal
1 Remove the main board.
(Disconnecting the hall sensor and feedback cables is
not required.)
2 Unscrew the 6 screws holding the pressure sensor
board in place.
3 Remove the pressure sensor board.
Installation
1 Place the pressure sensor o-rings in the three holes.
2 Cover the o-rings with the pressure sensor board.
3 Insert the 6 screws. Tighten until the pressure sensor
board makes firm contact with the base.
4 Perform a Factory Pressure Sensor Calibration.
16.7 Replacing a Double Acting Pilot
Relay
Removal
1 Remove the Main Board. See procedure above.
2 Fully loosen the 2 spool block screws. By squeezing
the two screws toward each other, grip the spool
block and pull it straight out. Take care to slide the
spool straight out of the spool seat to avoid bending
the spool or damaging the clip spring. The small clip
spring should remain attached to the spool.
3 Remove the first manifold gasket.
4 Remove the 2 manifold screws.
5 Remove the manifold assembly.
6 Remove the second manifold gasket and
7 manifold o-ring.
Installation
1 Place the manifold gasket and manifold o-ring into the
base.
2 Place the manifold assembly.
3 Place the 2 manifold screws.
4 Place the manifold gasket.
Pressure
5 Ensure the clip spring is oriented properly on the
Sensor
spool. Ensure the spool is oriented properly in the
Connector
block.
Slide the spool/block/clip spring assembly onto the
manifold ensuring the proper placement of the spool
Hall
and clip spring into the piston slot.
Sensor
6 Place the 2 spool block screws.
Connector
7 Calibrate.
39
FCD LGENIM0105-00
See procedure above.
Figure 29: Pressure Sensor Board
(See Figure 31: Clip Spring Orientation.)
Field Trial Version – Printed October 28, 2011
Pressure
Sensor
Screws