Fisher FIELDVUE DVC6200f Instruction Manual page 248

Maintenance and Troubleshooting
July 2013
Table 7‐2. Instrument Troubleshooting (Continued)
Symptom
10 Valve does not stroke from 0 to
100% with set point change
11 Deviation between set point and
actual valve position remains.
12 The valve cycles, does not stay on
set point.
13 Valve responds too slowly.
13 Valve responds too slowly.
246
Possible Cause
9c Instrument is in fault state.
9d The valve has failed.
9e The I/P converter or relay has failed.
10a Insufficient supply pressure or leak in pneumatic
connections.
10b Setpoint may be limited.
11a Digital valve controller output is in cutoff.
11b Digital valve controller is not calibrated correctly
11c Incorrect turning. Tuning that is too conservative will
result in excess error.
12a Large amount of packing friction.
13a Insufficient instrument gain.
13b I/P converter input filter clogged or air blockage in
I/P ass'y nozzle block.
13c O‐ring(s) between I/P converter missing or hard and
flattened losing seal.
13d I/P ass'y out of spec.
13e Defective gasket.
13f Defective relay.
13g If responds slowly only upon air demand, there may
be a restriction in the air line, the supply run may be
excessively long, or the supply regulator may be
defective or capacity not large enough.
9c Set Clear FState to Clear (Refer to Fault State on
page 47 of the Detailed Setup / Blocks Section, or host
system documentation).
9d Apply a pneumatic pressure to the valve actuator
and check valve action.
9e Replace the I/P converter or relay (see Replacing the
I/P Converter on page 238).
10a Check supply pressure and supply pressure
regulator setting. Check for leaks around pneumatic
connections.
10b Check the AO Block values of SP_HI_LIMIT and
SP_LO_LIMIT (see page 122 or host system
documentation).
11a Check values for Travel Cutoff High and Travel
Cutoff Low (see page 67 or host system
documentation).
11b Perform Auto or Manual Travel Calibration (Travel
Calibration on page 214.)
11c Perform Stabilizing/Optimize Valve Response
procedure to adjust tuning and stabilize/optimize
valve response (see Stabilize/Optimize on page 64).
12a1 Perform Stabilizing/Optimize Valve Response
procedure to adjust tuning and stabilize/optimize
valve response (see Stabilize/Optimize on page 64).
12a2 Use a larger size actuator.
13a Perform Stabilize/Optimize Valve Response
procedure to adjust tuning and stabilize valve
response (see Stabilize/Optimize on page 64).
13b1 Replace I/P converter filter (see Replacing the I/P
Filter on page 237).
13b2 Replace I/P converter (see Replacing the I/P
Converter on page 238).
13c Replace O‐ring(s) (refer to the I/P Converter section
on page 237).
13d I/P ass'y nozzle may have been adjusted.
Verify drive signal (55% to 80%) (refer to Elect and
Config on page 69 or host system documentation).
Replace I/P ass'y if drive signal is continuously high or
low (see Replacing the I/P Converter on page 238).
13e Check gasket for closed holes, excessive
deformation due to overtightening or "oozing". If
necessary, replace gasket (see the beginning of this
section).
13f Remove relay, inspect for missing Belleville washer,
missing valve spring, missing valve plug. Inspect "lip"
under top O‐ring for breakage due to relay removal.
Inspect O‐rings and replace if hard or damaged.
Replace parts or relay if I/P ass'y good and air passages
not blocked (see Replacing the Pneumatic Relay on
page 240).
13g1 Check supply line to ensure it is not clogged or
damaged. Replace if necessary.
13g2 If supply run is excessively long, a volume tank
may need to be installed on the the supply side of the
pressure regulator
13g3 Replace supply regulator
-Continued-
Instruction Manual
D103412X012
Action