5-7
Troubleshooting and Maintenance
TABLE 5-5. (continued).
Symptom Corrective Action
Erratic PV Reading LOOP WIRING
CAUTION
Do not use higher than the specified voltage to check the loop
or damage to the device may result.
• Check for adequate voltage to the device. It should be
11 to 55 V dc at the device terminals.
• Check for intermittent shorts, open circuits, and
multiple grounds.
PROCESS PULSATION
• Adjust the electronic damping (see page 4-4).
DEVICE ELECTRONICS
• Connect a Model 275 to check the sensor limits to ensure
calibration adjustments are within the sensor range and that
calibration is correct.
• Make sure the post connectors are clean.
• Confirm that the electronics housing is properly sealed
against moisture.
• If the electronics are still suspect, substitute new electronics.
IMPULSE PIPING
• Check for entrapped gas in liquid lines and for liquid in
gas lines.
• Make sure that process fluid has not frozen within the
process flange.
SENSING ELEMENT
• The sensing element is not field repairable and must be
replaced if found to be defective. Check for obvious defects,
such as a punctured isolating diaphragm or fill fluid loss, and
contact your nearest Rosemount Service Center.
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