Owner's manual

b.
J/P Converter. Use the following procedure for
replacement of the current to pneumatic signal
converter (I/P).
WARNING
Before performing any maintenance or
repair action on power positioner, shut off
supply air, signal air, and any electrical
supply or electronic signals to power
positioner. Isolate power positioner from all
systems connected to the power positioner.
Severe injury or death may result from
large torque power positioner is capable of
producing, or from electrical shock.
1. Remove power positioner from service.
2. Tam electrical signal transmitter off, making
sure no electxical voltage or current is being
applied to the I/P.
3. Bleed off any residual air pressure through
connection of signal tubing to I/P.
4. Remove inlet and outlet piping to I/P.
5. Remove input signal leads from I/p’s screw
terminals. If screw terminals are not installed
on I/P, remove I/P pigtails from screw
terminals.
6. Remove screws securing old I/P converter to
mounting bracket and discard I/P.
7. Attach inlet and outlet piping to respective
ports 0” I/P.
8. Connect leads to electrical signal wires. For
direct acting power positioners, connect
positive signal to I/P’s black lead and
negative signal to white lead. For reverse
acting power positioners, connect positive
lead to I/p’s white signal and negative lead
to black signal.
9. Install new I/p to same mounting location,
sewing with old hardware.
10. Open supply air valves and test for leaks
using a “snoop” type leak detector.
11. Calibmte I/F and return unit to service.
Refer to paragraph 4-3 for calibration
procedures.
c. Pilot Valve. Use the following procedure to
replace the pilot valve.
Before performing any maintenance or
repair action on power positioner, shut off
supply air, signal air, and any electrical
supply or electronic signals to power
positioner. Isolate power positioner from alJ
systems connected to tbe power positioner.
Severe injury or death may result from
large torque power positioner is capable of
producing, or from electrical shock.
1. Remove power positioner from service.
2. Carefully hold upper end of pilot valve’s
stem assembly (1, Figure 7-2). Turn
connecting lii ball socket nut (3)
coanterclockwii and free connecting link
(2) from pilot valve stem assembly.
3. Disconnect supply air tabiig (4) from elbow
(5).
4. Remove socket head cap screws (6) that
secure pilot valve (7) and manifold (8) to
stand assembly (9). Remove pilot valve and
manifold.
5. Install new pilot valve (7). pilot valve gasket
(lo), and manifold (8) onto stand assembly
(9.
6. Attach supply air tubing (4) to elbow (5).
Open supply air shut off valve and test for
leaks using a “snoop” type leak detector.
Close supply air valve.
7. Carefully hold upper end of new pilot
valve’s stem assembly (1). Attach stem
assembly to connecting lii (2) by turning
connecting link’s ball socket nut (3)
clockwise.
8. Refer to paragraph 4-2 and calibrate stroke
of power positioner.
9. Return power positioner to service.