Emerson Process Management 1500 manual Troubleshooting, Symptom, Cause, Possible remedy, Defaults

Troubleshooting

Table 11-5Process variables problems and possible remedies continued

Symptom	Cause	Possible remedy
Erratic non-zero flow rate under	RF interference	Check environment for RF interference.
no-flow conditions		See Section 11.14.4.
	Wiring problem	Verify all sensor-to-transmitter wiring
		and ensure the wires are making good
		contact.
	Incorrectly grounded 9-wire cable (in	Verify 9-wire cable installation. Refer to
	remote core processor with remote	Appendix B for diagrams, and see the
	transmitter installations)	installation manual for your transmitter.
	Vibration in pipeline at rate close to	Check environment and remove source
	sensor tube frequency	of vibration.
	Leaking valve or seal	Check pipeline.
	Inappropriate measurement unit	Check configuration. See
		Section 11.19.
	Inappropriate damping value	Check configuration. See Section 4.5.5
		and Section 6.6.
	Slug flow	See Section 11.17.
	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	Output wiring problem	Verify wiring between transmitter and
is steady		receiving device. See the installation
		manual for your transmitter.
	Problem with receiving device	Test with another receiving device.
	Inappropriate measurement unit	Check configuration. See
		Section 11.19.
	Inappropriate damping value	Check configuration. See Section 4.5.5
		and Section 6.6.
	Excessive or erratic drive gain	See Section 11.23.3 and
		Section 11.23.4.
	Slug flow	See Section 11.17.
	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.

Compensation

Measurement Performance

Troubleshooting

Defaults

Configuration and Use Manual 99