Collect Pickoff Voltage Data; Check For Electrical Shorts - Emerson Micro Motion 2700 Configuration And Use Manual

Table 12-10:
Possible cause
No tube vibration in sensor
Moisture in the sensor elec-
tronics
The sensor is damaged, or
sensor magnets may have be-
come demagnetized
12.27.1

Collect pickoff voltage data

Pickoff voltage data can be used to diagnose a variety of process and equipment
conditions. Collect pickoff voltage data from a period of normal operation, and use this
data as a baseline for troubleshooting.
Procedure
1.
2.
12.28

Check for electrical shorts

Shorts between sensor terminals or between the sensor terminals and the sensor case can
cause the sensor to stop working.
Table 12-11:
Possible cause
Moisture inside the junction box
Liquid or moisture inside the sensor
case
Internally shorted feedthrough
Faulty cable
Improper wire termination
Configuration and Use Manual
Possible causes and recommended actions for low pickoff voltage
(continued)
Recommended actions
•
•
•
•
Eliminate the moisture in the sensor electronics.
Replace the sensor.
Navigate to the pickoff voltage data.
Observe and record data for both the left pickoff and the right pickoff, over an
appropriate period of time, under a variety of process conditions.
Possible causes and recommended actions for electrical shorts
Check for plugging.
Ensure sensor is free to vibrate (no mechanical binding).
Verify wiring.
Test coils at sensor. See Section
Recommended action
Ensure that the junction box is dry and no corrosion is
present.
Contact Micro Motion.
Contact Micro Motion.
Replace the cable.
Verify wire terminations inside sensor junction box. The
Micro Motion document titled 9-Wire Flowmeter Cable Prepa-
ration and Installation Guide may offer some assistance.
Troubleshooting
12.28.1.
241