
Configuration and Use Manual
177
Maintenance and Troubleshooting
Adm
inis
tration
Com
p
one
n
ts
Mai
n
tenan
c
e and
T
roub
le
sh
oo
tin
g
Op
erator Int
e
rface
Table 15-3
Process variables problems and possible remedies
Symptom
Cause
Possible remedy
Steady non-zero flow rate under
no-flow conditions
Misaligned piping (especially in new
installations)
Correct the piping.
Open or leaking valve
Check or correct the valve mechanism.
Bad sensor zero
Rezero the meter. See Section 5.6.
Bad flow calibration factor
Verify characterization. See
Section 15.13.
Erratic non-zero flow rate under
no-flow conditions
RF interference
Check environment for RF interference.
Wiring problem
Verify all sensor-to-transmitter wiring
and ensure the wires are making good
contact.
Incorrectly grounded 9-wire cable (in
remote core processor with remote
transmitter installations)
Verify 9-wire cable installation. See the
Model 3711 installation manual.
Vibration in pipeline at rate close to
sensor tube frequency
Check environment and remove source
of vibration.
Leaking valve or seal
Check pipeline.
Inappropriate damping value
Check configuration. See Section 5.4.
Slug flow
Plugged flow tube
Check drive gain and tube frequency.
Purge the flow tubes.
Moisture in sensor junction box
Open junction box and allow it to dry.
Do not use contact cleaner. When
closing, ensure integrity of gaskets and
O-rings, and grease all O-rings.
Mounting stress on sensor
Check sensor mounting. Ensure:
• Sensor is not being used to support
pipe.
• Sensor is not being used to correct
pipe misalignment.
• Sensor is not too heavy for pipe.
Sensor cross-talk
Check environment for sensor with
similar (±0.5 Hz) tube frequency.
Incorrect sensor orientation
Sensor orientation must be appropriate
to process fluid. See the installation
manual for your sensor.
Erratic non-zero flow rate when flow
is steady
Problem with receiving device
Test with another receiving device.
Inappropriate damping value
Check configuration. See Section 5.4.
Excessive or erratic drive gain
Slug flow
Plugged flow tube
Check drive gain and tube frequency.
Purge the flow tubes.
Wiring problem
Verify all sensor-to-transmitter wiring
and ensure the wires are making good
contact.
Summary of Contents for Micro Motion 3711
Page 32: ...24 Micro Motion Model 3711 Gas Flow Computers ...
Page 44: ...36 Micro Motion Model 3711 Gas Flow Computers ...
Page 56: ...48 Micro Motion Model 3711 Gas Flow Computers ...
Page 68: ...60 Micro Motion Model 3711 Gas Flow Computers ...
Page 92: ...84 Micro Motion Model 3711 Gas Flow Computers ...
Page 108: ...100 Micro Motion Model 3711 Gas Flow Computers ...
Page 140: ...132 Micro Motion Model 3711 Gas Flow Computers ...
Page 196: ...188 Micro Motion Model 3711 Gas Flow Computers ...
Page 210: ...202 Micro Motion Model 3711 Gas Flow Computers ...
Page 233: ......