Emerson 4320, Instruction Manual, Page: 57 / 64

Instruction Manual
D103621X012
4320
January 2018
57
Table 5. Instrument Troubleshooting
Symptom Possible Cause Action
1. Actuator does not move 1a. No (or low) supply air pressure 1a. Check supply air pressure
1b. Air connections are incorrect for actuator type 1b. Correct air connections
2. Display shows “Span Error” when performing a
manual calibration
2a. Rotary feedback magnet is off 90
_
2a. Rotate feedback magnet 90
_
in either
direction
2b. Linear or arched array travels outside of
marked range, as indicated by the white end
marks on the array and the mid point on the back
of the 4320 housing. See page 16. 2b. Adjust array and travel to fall within range of
array end marks. See page 16.
3. Actuator moves once during automatic
calibration and then stops 3a. Rotary feedback magnet is off 90
_
3a. Rotate feedback magnet 90
_
in either
direction
3b. Linear or arched array travels outside of
marked range, as indicated by the white end
marks on the array and the mid point on the back
of the 4320 housing. See page 16. 3b. Adjust array and travel to fall within range of
array end marks. See page 16.
3c. Actuator not reaching stable position 3c. Adjust supply pressure to ensure that actuator
reaches end-stops
4. No response / excessive calibration time when
performing Automatic Calibration 4a. Rotary feedback magnet is off 90
_
4a. Rotate feedback magnet 90
_
in either
direction
4b. Linear or arched array travels outside of
marked range, as indicated by the white end
marks on the array and the mid point on the back
of the 4320 housing. See page 16. 4b. Adjust array and travel to fall within range of
array end marks. See page 16.
4c. Actuator not reaching stable position 4c. Adjust supply pressure to ensure that actuator
reaches end-stops
Replacing the instrument
To replace an instrument that has been previously mounted to a control valve, perform the following basic steps:
Instrument Removal
Remove the bolts connecting the 4320 housing to the mounting bracket.
Note
The magnet assembly may remain on the valve stem (or shaft).
When replacing the instrument, be sure to follow the appropriate mounting procedure. Once the instrument is
mounted, perform the calibration routine before putting back in to service.
WARNING
During calibration the valve will move full stroke. To avoid personal injury and property damage caused by the release of
pressure or process fluid, isolate the valve from the process and equalize pressure on both sides of the valve or bleed off the
process fluid.