On 24th Jan 2014, we at Essar Steel, Surat, India, faced problem with one of the integrated "DISPLAY CARDS" (PAPRT NO: 08732-0006-E001) of Magnetic flowmeter (Model N0. 8732EST2A1NAM4, Sl. No. 06001472), which was supplied by Emerson (Rosemount) on 16 May 2013. Fault message on flowmeter display was “ELECTRONICS FAIL”.
Output delivered by the flowmeter at that time was 21 mA. As per our water control loop, if water flow is more than set point, water control valve will tend to close. And in that failure situation on 24th Jan 2014, valve had come to almost closed condition (32% approx. open due to safety settings) and water flow shown on our WinCC HMI was 814 LPM against 430 LPM water set point. (Actual Water Flow in 32% open condition must be surely less than 400LPM)
After replacing the faulty display card with new healthy one, problem was resolved.
We have faced this problem in 4 Nos flowmeter displays in last 3 years.
This is very critical situation for us as our "Stell Slab Casting Process" gets terminated, resulting in heavy losses.
Can anybody help me to solve this problem?
If the 8732E transmitter goes into a failure status, it will automatically force the outputs to an alarm level. This is a normal operation for the transmitter and is meant to drive the output to off-scale reading as a notification of a failure. If it would be preferable for your control system to drive the output to a low off-scale output there are two options for the alarm level - High or Low. A high alarm setting will drive the mA output 22.5 mA. A low alarm setting will drive the mA output to 3.75 mA. The setting for High versus Low is controlled by a hardware switch on the electronics board. The default position for the switch is High. Since your unit has a display, you would have to remove it to see this switch on the face of the electronics. Further details regarding changing switch settings can be found in the Reference Manual in section 2 using the following link - www2.emersonprocess.com/.../00809-0100-4662.pdf
If you experience the "ELECTRONICS FAIL" message again, the first step is to cycle power to the device to see if the error will clear. There is a possibility for unclean or insufficient power, bad earth grounds, or other electrical noise can disrupt operation of the electronics and force it into a failure mode. If cycling power to device clears the error message it was likely a temporary event that triggered the status as opposed to a permanent failure. If cycling power does clear the error message, you should investigate the installation to make sure clean sufficient power is being supplied and the power supply and device are grounded properly. Also survey the area for sources of electrical noise - pumps, motors, drives, welding, radio signals, etc. If cycling power doesn't clear the error message and the device has been installed properly then the electronics, not the display, should be replaced. More details regarding troubleshooting and maintenance can be found in the Reference Manual mentioned above.