Troubleshooting
If fill accuracy is unsatisfactory or has changed, or if fill variation is too great:
•Implement overshoot compensation (if not already implemented).
•If standard AOC calibration is implemented, repeat the AOC calibration.
•If rolling AOC calibration is implemented, try increasing the AOC Window Length value.
•Check for mechanical problems with the valve.
11.14Diagnosing wiring problems
Use the procedures in this section to check the transmitter installation for wiring problems.
11.14.1Checking the power supply wiring
To check the power supply wiring:
1.Verify that the correct external fuse is used. An incorrect fuse can limit current to the transmitter and keep it from initializing.
2.Power down the transmitter.
3.Ensure that the power supply wires are connected to the correct terminals. Refer to Appendix B for diagrams.
4.Verify that the power supply wires are making good contact, and are not clamped to the wire insulation.
5.Use a voltmeter to test the voltage at the transmitter’s power supply terminals. Verify that it is within the specified limits. For DC power, you may need to size the cable. Refer to Appendix B for diagrams, and see your transmitter installation manual for power supply requirements.
11.14.2Checking the sensor-to-transmitter wiring
To check the
•The transmitter is connected to the sensor according to the wiring information provided in your transmitter installation manual. Refer to Appendix B for diagrams.
•The wires are making good contact with the terminals.
If the wires are incorrectly connected:
1.Power down the transmitter.
2.Correct the wiring.
3.Restore power to the transmitter.
11.14.3Checking grounding
The sensor and the transmitter must be grounded. If the core processor is installed as part of the sensor, it is grounded automatically. If the core processor is installed separately, it must be grounded separately. See your sensor and transmitter installation manuals for grounding requirements and instructions.
102 | Micro Motion® Model 1500 Transmitters with the Filling and Dosing Application |
