Emerson Rosemount 2151N Reference Manual page 71

Reference Manual
00809-0000-4851 Rev AD
December 2023
Table 5-3 – Troubleshooting
POTENTIAL
SYMPTOM
SOURCE
Primary Element
Impulse Piping
Transmitter
High Output
Electronics
Transmitter
Electronics Failure
Sensor Module
Power Supply
Primary Element
Loop Wiring
Low Output
or No Output
Impulse Piping
Transmitter
Electronics
Connections
Continued on Next Page
Maintenance & Troubleshooting
CORRECTIVE ACTION
Check for restrictions at primary element, improper installation or
poor condition. Note any changes in process fluid properties that
may affect output.
• Check for leaks or blockage.
• Ensure blocking valves are fully open.
• Check for entrapped gas in liquid lines, or liquid in dry lines.
• Ensure that density of fluid in impulse line is unchanged.
• Check for sediment in transmitter process flanges.
Make sure that filter pins and the sensor module connections are
clean. If the electronics are still suspect, substitute new
electronics.
Determine faulty circuit board by trying spare electronics
assembly or terminal block assembly. Replace faulty assembly.
NOTE: See Sensor Module Checkout section. The sensing
element is not field repairable and must be replaced if found to be
defective. See Disassembly Procedure for instructions on
disassembly. Check for obvious defects (i.e. punctured isolating
diaphragm, etc.) and contact Rosemount Nuclear.
Check the power supply output voltage at the transmitter.
Check the installation and condition of primary element.
Note any changes in process fluid properties that may affect
output.
Do not use more than 55 volts to check the loop, or
damage to the transmitter electronics may result.
• Check for inadequate voltage to the transmitter.
• Check the milliamp rating of the power supply against the total
current being drawn for all transmitters being powered.
• Check for intermittent shorts, open circuits, or multiple grounds.
• Check for proper polarity at the signal terminal.
• Check loop impedance.
• Check wire insulation to detect possible shorts to ground.
• Ensure that the pressure connection is correct.
• Check for leaks or blockage.
• Check for entrapped gas in liquid lines, or liquid in dry lines.
• Check for sediment in transmitter process flanges.
• Ensure that blocking valves are fully open and that bypass
valves are tightly closed.
• Ensure that density of fluid in the impulse line is unchanged.
• Ensure that calibration adjustments are in allowable range.
• Check for short in sensor leads.
• Make sure filter pins are clean, and check the sensor module
connections.
• If the electronics are still suspect, substitute new electronics.
Rosemount 2151N
CAUTION
62