Emerson Rosemount 8732EM, Справочное руководство

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Common Magmeter Issue
(continued)
Table 12-7:
Symptom Potential cause Corrective action
Electronics failure Verify transmitter operation with an 8714D Calibra-
tion Standard or replace the electronic stack
Blown fuse Check the fuse and replace with an appropriately
rated fuse, if necessary
Output at 4 mA Transmitter in multidrop mode Configure Poll Address to 0 to take transmitter out
of multidrop mode
Low Flow Cutoff set too high Configure Low Flow Cutoff to a lower setting or in-
crease flow to a value above the low flow cutoff
PZR Activated Open PZR switch at terminals 5 and 6 to deactivate
the PZR
Flow is in reverse direction Enable Reverse Flow function
Shorted coil Coil check – perform sensor test
Empty pipe Fill pipe
Electronics failure Verify transmitter operation with an 8714D Calibra-
tion Standard or replace the electronics stack
Output will not reach 20
mA Loop resistance is greater than 600
ohms Reduce loop resistance to less than 600 ohms
Perform analog loop test
Insufficient supply voltage to analog
output Verify analog output supply voltage
Perform analog loop test
Output at 20.8 mA Transmitter not ranged properly Reset the transmitter range values – see Section 5.2
Check tube size setting in transmitter and make
sure it matches the actual tube size – see
Section 5.2
Output at alarm level Electronics failure Cycle power. If alarm is still present, verify transmit-
ter operation with an 8714 D Calibration Standard
or replace the electronics stack
Open coil circuit Check coil drive circuit connections at the sensor
and at the transmitter
Analog output diagnostic alarm is ac-
tive See AO diagnostic alarm
Coil power or coil current is over limit Check coil drive circuit connections at the sensor
and at the transmitter
Cycle power. If alarm is still present, verify transmit-
ter operation with an 8714 D Calibration Standard
or replace the electronics stack
Connected to incompatible sensor See Appendix D
Pulse output at zero, re-
gardless of flow Wiring error Check pulse output wiring at terminals 3 and 4. Re-
fer to wiring diagram for pulse counter and pulse
output. See
Section 6.2.1 .
PZR activated Remove signal at terminals 5 and 6 to deactivate
the PZR.
Troubleshooting
Reference manual 167