Emerson Rosemount 2088 Reference Manual page 73

Section 6: Troubleshooting
March 2014
Table 6-1. Rosemount 2088 troubleshooting table for 4-20 mA output
Symptom
Transmitter milliamp reading is
zero
Transmitter Not Communicating
with Field Communicator
Transmitter milliamps reading is
low or high
Transmitter will not respond to
changes in applied pressure
Digital Pressure Variable reading
is low or high
Digital Pressure Variable reading
is erratic
Milliamps reading is erratic
64
Corrective actions
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
Verify terminal voltage is 10.5 to 42.4 Vdc
Check loop resistance, 250 minimum (PS voltage -transmitter voltage/loop
current)
Check that power wires are connected to signal terminals and not test terminals
Verify clean DC Power to transmitter (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
Verify applied pressure
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
Check impulse piping or manifold for blockage
Verify applied pressure is between the 4 and 20 mA points
Verify the output is not in alarm condition
Verify transmitter is not in loop test mode
Verify transmitter is not in multidrop mode
Check test equipment
Check impulse piping for blockage or low fill in wet leg
Verify transmitter is calibrated properly
Check test equipment (verify accuracy)
Verify pressure calculations for application
Check application for faulty equipment in pressure line
Verify transmitter is not reacting directly to equipment turning on/off
Verify damping is set properly for application
Verify power source to transmitter has adequate voltage and current
Check for external electrical interference
Verify transmitter is properly grounded
Verify shield for twisted pair is only grounded at one end
Reference Manual
00809-0100-4108, Rev BA
Troubleshooting