Fisher-Rosemount 3095FT, Manual

Page: 105 / 184

5-7
Troubleshooting and Maintenance
Power Supply
• Check the output voltage of the power supply at the transmitter.
It should be 11 to 35 V dc with no load at the transmitter
terminals.
Transmitter Electronics
• Connect a personal computer and use the User Interface Software
to check the sensor limits to ensure calibration adjustments are
within the sensor range and that calibration is correct for the
pressure being applied.
• Connect a personal computer and using the User Interface
Software, select Maintenance, Transmitter, Self Test
(see Page 4-34) to detect any electronic failures.
• 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.
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.
Symptom: Erratic PV Reading Potential Source and Corrective Action
Orifice Plate
• Check the installation and condition of the orifice plate.
Loop Wiring
• Check for adequate voltage to the transmitter. It should be 11 to
35 V dc with no load at the transmitter terminals.
• Check for intermittent shorts, open circuits, and multiple
grounds.
Do not use over 35 volts to check the loop, or damage to the
transmitter electronics may result.
Do not use over 35 volts to check the loop, or damage to the
transmitter electronics may result.