Flowserve 3200MD - Manual (Page 26)

User Instructions - Digital Positioner 3200MD LGENIM0059-09 12/13
26
8.7 Main PCB Assembly
The main printed circuit board (PCB) assembly contains the circuit
board and processor that perform control functions of the positioner.
The main PCB is to be replaced as a unit. None of the components
on the main PCB are serviceable.
Replacing Main PCB Assembly
To replace the main PCB assembly, refer to Figure 11 and 15 and
proceed as outlined below. The following tool is required:
• Phillips screwdriver
 WARNING: Observe precautions for handling electrostati-
cally sensitive devices.
1. Make sure the valve is bypassed or in a safe condition.
2. Disconnect the power and air supply to the unit.
3. Remove the main cover.
4. Remove the plastic board cover by removing the three retaining
screws (See Figure 15).
5. Remove the fi ve wire connections from the main PCB assembly
(six wire connections if the unit is equipped with the 4-20 mA
analog output option) (See Figure 11).
6. Remove the retaining screw from the main PCB assembly and
lift the main PCB out of the housing (See Figure 15).
7. Install the new main PCB into the housing. Insert the retaining
screw through the board into the threaded boss and tighten,
using a Phillips screwdriver. Do not overtighten.
8. If the old main PCB is equipped with a 4-20 mA analog output
board, gently lift the board off the main PCB. Align the two con-
nectors of the 4-20 mA output board with the mating sockets on
the main PCB and gently press the connectors together.
9. Reinstall the fi ve wire connections (six wire connections if the
unit is equipped with the 4-20 mA analog output option) (See
Figure 11).
10. Install the plastic board cover. Insert the three retaining screws
through the plastic cover into the threaded boss and tighten
evenly, using a Phillips screwdriver. Do not overtighten (See
Figure 15).
11. Reinstall all covers.
12. Reconnect power and air supply to the positioner and reconfi g-
ure the positioner being sure to perform a stroke calibration.
8.8 Pressure Sensor Board
The pressure sensor board contains two pressure sensors that
measure the pressure on output ports 1 and 2. The actuator pres-
sure sensors are used in the positioner control algorithm to enhance
valve stability. In positioners with Advanced diagnostics, pressure
data is gathered for supply pressure alarm, signatures and data
logging. In positioners with Pro diagnostics, pressure data is used
for full on-line diagnostic analyses. For optimal performance, the
actuator pressure sensors need to be calibrated. The actuator pres-
sure sensor calibration is performed using a HART 375 Handheld
Communicator or confi guration software such as ValveSight.
Removing the Pressure Sensor Board
To replace the pressure sensor board, refer to Figures 11, 15 and 25
and proceed as outlined below. The following tools are required:
• Phillips screwdriver
 WARNING: Observe precautions for handling electrostati-
cally sensitive devices.
1. Make sure the valve is bypassed or in a safe condition.
2. Disconnect the power and air supply to the unit.
3. Remove the main cover.
4. Remove the plastic board cover by removing the three retaining
screws (See Figure 15).
5. Disconnect the ribbon cable on the pressure sensor board from
the PCB assembly (See Figure 11).
6. Remove the two screws holding the pressure sensor board to
the housing. Lift the metal stiffener plate off the pressure sensor
board and set aside for future use.
7. Remove the pressure sensor board.
Installing the Pressure Sensor Board
The pressure sensor board is installed on the advanced model only.
To install the pressure sensor board, refer to Figures 11, 15 and 25
and proceed as outlined below. The following tools are required:
• Phillips screwdriver
• Torque wrench
 WARNING: Observe precautions for handling electrostatic
sensitive devices.
1. Verify that the two pressure sensor O-rings (item 15) are in
place in the housing.
2. Set the pressure sensor board assembly in place so that the
O-rings make contact with the faces of the pressure sensors.
3. Place the metal stiffener plate (item 12) on top of the pressure
sensor board over the pressure sensors and align the two holes
in the pressure sensor plate with the threaded bosses in the
housing.
4. Insert two screws through the stiffener plate and pressure
sensor board into the threaded holes in the housing and tighten
evenly, to 8 in-lb.
5. Connect the ribbon cable on the pressure sensor board to the
main PCB assembly.