Emerson Rosemount 8750W - Diagnostic Messages

160
Reference Manual
00809-0300-4750, Rev CA
Troubleshooting
March 2016
Troubleshooting
9.4 Diagnostic messages
Problems in the magnetic flowmeter system are usually indicated by incorrect output
readings from the system, error messages, or failed tests. Consider all sources in identifying
a problem in the system.
Table 9-1. Basic Diagnostic Messages
Error message Potential cause Corrective action
Empty Pipe Empty pipe •None - message will clear when pipe is full
Wiring error •Check that wiring matches appropriate wiring diagrams
Electrode error •Perform sensor tests - see Table 9-8 on page 175
Conductivity less than 5
microsiemens per cm
•Increase conductivity to greater than or equal to 5
microsiemens per cm
Intermittent diagnostic •Adjust tuning of empty pipe parameters - see Section 8.4.1
Coil Open Circuit Improper wiring •Check coil drive wiring and sensor coils
Perform sensor tests - see Table 9-8 on page 175
Other manufacturer’s sensor •Change coil current to 75 mA - set calibration numbers to
10000550100000030
•Perform a universal auto-trim to select the proper coil current
Electronics board failure •Replace 8750W electronics stack
Coil circuit open fuse •Return the unit to the factory for fuse replacement
Auto Zero Failure Flow is not set to zero •Force flow to zero, perform auto zero trim
Unshielded cable in use •Change wire to shielded cable
Moisture problems •See Table 9-8 on page 175
Auto-Trim Failure No flow in pipe while performing
Universal Auto Trim
•Establish a known flow rate, and perform universal auto-trim
calibration
Wiring error •Check that wiring matches appropriate wiring diagrams - see
“Implementing a Universal Transmitter” on page 221
Flow rate is changing in pipe
while performing Universal
Auto-Trim routine
•Establish a constant flow rate, and perform universal auto-trim
calibration
Flow rate through sensor is
significantly different than value
entered during Universal
Auto-Trim routine
•Verify flow in sensor and perform universal auto-trim
calibration
Incorrect calibration number
entered into transmitter for
Universal Auto-Trim routine
•Replace sensor calibration number with 1000005010000000
Wrong sensor size selected •Correct sensor size setting - see “Line size” on page 33
Sensor failure •Perform sensor tests - see Table 9-8 on page 175
Electronics Failure Electronics self check failure •Cycle power to see if diagnostic message clears
•Replace Electronics stack
Electronics Temp
Fail
Ambient temperature exceeded
the electronics temperature
limits
•Move transmitter to a location with an ambient temperature
range of -40 to 140 °F (-40 to 60 °C)