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98
Reference Manual
00809-0100-4140, Rev AA
January 2017
6.3
Troubleshooting for 4-20 mA Output
Table 6-1. Rosemount 2140 Troubleshooting for 4-20 mA Output
6.4
Diagnostic messages
Listed in the below sections are detailed table of the possible messages that will appear on
either the LCD/LOI Display, a Field Communicator, or an AMS system. Use the tables below
to diagnose particular status messages.
Good
Failed – fix now
Maintenance – fix soon
Advisory
Listed in the below sections are detailed tables of the possible messages that will appear on
either: LOI display, Field Communicator, or an AMS system.
Symptom
Corrective actions
Level detector milliamp reading
is zero
Verify terminal voltage is 10.5 to 42.4 Vdc at signal terminals
Check power wires for reversed polarity
Check that power wires are connected to signal terminals
Check for open diode across test terminal
Level detector not communicating
with Field Communicator
Verify terminal voltage is 10.5 to 42.4 Vdc
Check loop resistance, 250
minimum (PS voltage -level detector
voltage/loop current)
Check that power wires are connected to signal terminals and not test
terminals
Verify clean DC Power to level detector (Max AC noise 0.2 volts peak to peak)
Verify the output is between 4 and 20 mA or saturation levels
Have Field Communicator poll for all addresses
Level detector milliamp reading is
low or high
Verify 4 and 20 mA range points
Verify output is not in alarm condition
Perform analog trim
Check that power wires are connected to the correct signal terminals
(positive to positive, negative to negative) and not the test terminal
Milliamp reading is erratic
Verify power source to level detector has adequate voltage and current
Check for external electrical interference
Verify level detector is properly grounded
Verify shield for twisted pair is only grounded at one end
Summary of Contents for Rosemount 2140
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Page 8: ...VI Reference Manual 00809 0100 4140 Rev AA Contents January 2017 Contents ...
Page 14: ...4 Reference Manual 00809 0100 4140 Rev AA Introduction January 2017 Introduction ...
Page 112: ...102 Reference Manual 00809 0100 4140 Rev AA Troubleshooting January 2017 Troubleshooting ...
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