Specifications

SECTION V. TROUBLESHOOTING
5-l. OVERVIEW. Troubleshooting of common problems
the related probable cause, and finally by what action
is provided for in troubleshooting chart (Table 5-l).
is necessary to correct the defect.
The chart describes common problems, followed by
5-2. TROUBLJZSHOOTTNG CHART. Refer to Table 5-l.
Table 5-1. Troubleshootim Chart.
PROBLEM
1. Erratic operation
2. No response from
power positioner to a
signal air pressure.
change
3. Power positioner
does not remain at
setpoint; continues to
CVCk
4. System over shoots
or under shoots
setpoint
5. Sluggish operation
6. Power positioner
operates nor”lally
but flow that is being
controlled remains
“nchaneed
I. Power positioner
locks up and won’t
operate with transfer
valve in automatic
mode
CAUSE
Pilot valve sticking.
Linkage binding or loose.
Manual lock engaged.
Air supply shutoff valve closed.
Ruptured receiver diaphragm.
Cylinder head gasket leak.
Bypass valve air connection loose
Bypass valve. leaking internally.
I/P o”t of calibration.
I/p failure.
Piston stroke travel not properly set.
Cam not shaped properly,
Pin hole in diaphragm.
Air filter/separator full of water, oil, or
sediment.
Air filter dii.
Ambient temperature is lower than the
power positioner is designed for.
Device being controlled has a broken
valve stem or co”nectio” to the
linkage.
Hole in air lock diaphragm(s).
CORRECTION
Clean or replace pilot valve. Refer t” paragraph 6-4
for cleaning procedures and paragraph 7-2~
for replacement procedures.
Linkage pivot joints corroded, dirty, or worn. Clean
and lubricate or reulace “arts.
Disengage manual lock.
open air supply valve.
Replace diaphragm. Refer to paragraph 7.2.~.
Replace leaking gasket. Refer to paragraph 7-2.x.
Tighten or replace air connection.
Replace bypass valve.
Calibrate UP. Refer to paragraph 4-3.
H
Replace J/P per paragraph 8.3.b.
Calibrate stroke travel of piston.
Refer to
paragraph 4-2.
Replace cam. Refer to paragraph 7.2.g.
Replace diaphragm. Refer to paragraph 7.2.~.
Drain air filter/separator. Refer to paragraph 6-5.
Replace filter element. Refer to paragraph 7.2.b.
Install power positioner heater.
Repair or replace controlled device.
Replace air lock diaphragm(s),