The module burns out as soon as the magnetostrictive level gauge is put into use – what’s going on?
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Magnetostrictive level gauge, two-wire system, 4-20ma. It works fine when connected to the upper line, but after one or two days the signal becomes abnormal and reaches full scale, causing the module to get damaged. What’s going on? Several level gauge manufacturers have been replaced, and the same problem persists. Is there an issue with the instrument’s wiring or is it a quality problem with the instrument itself? How should one detect problems with the instrument wiring? The multimeter shows that the 24VDC power supply for the circuit is functioning properly, and there are no issues with the circuit’s integration testing. I’m sincerely seeking help! Seeking help from kind people, thank you!
If a wiring issue is suspected, then the scene can be left behind. Connect a transmitter module to the AI channel in the control room to see if it gets damaged again
Thank you for the reply. That burnout of the module doesn’t happen right away; first, the signals become abnormal after some time, and then someone from the manufacturer comes to check it. During that inspection process, the module gets burned out. This has happened several times, it’s like being possessed by evil spirits. I tried using a separate power supply when the signal was abnormal, but the signal was still incorrect; I’m not sure if the instrument was already faulty at that time. Another issue is whether it is related to the medium used – in this case, water and dichloroethane – for measuring the level; the density difference is 1/1.25. Previously, it was suspected that volatile gases at the top of the tank might have damaged the internal circuitry of the gauge, but after the latest module failure, measures were taken to isolate the gauge’s components.
This phenomenon generally does not occur; the possibility of a fault in the primary instrument is low. The main thing to check is whether there is a short circuit in the power supply lines, or relative to ground
How to check the voltage of a wire relative to ground? It means that after removing the two wires, there should be no voltage measured with respect to ground, right?
Thoroughly check the insulation and grounding of the wiring. It can be measured using a megohmmeter (or other equipment for testing insulation and grounding).
Exaggeratingly speaking, the induced voltage burned out your module.
The module is burned out; there must be a short circuit somewhere, or maybe high voltage is present
Or is it a problem with the instrument power? I don’t know either; I’m just suspicious!
I’ve encountered such situations before: a watch on site would start jumping erratically at random times during the day, and one watch even caught fire; yet upon inspection, everything seemed to be fine. Later, while walking around the site, I saw a small maintenance project located about twenty to thirty meters away from the meter; welding was being done there. Since the welding wasn’t carried out in one fixed location, the welder probably didn’t want to go around attaching the grounding wire, so he simply clamped the welding machine’s grounding wire to the foundation of the pipe rack structure. I didn’t notice it at first; given the distance, I thought it wouldn’t have much impact. But when I checked the gauge, I saw that as soon as the welding torch was turned on, the gauge’s reading would change immediately. I tried it with a welder, and indeed it affected the gauge; I asked the welder to move the ground wire of the welding machine to another location, and once that was done, the gauge stopped giving errors. I still haven’t figured out what’s going on; it’s likely that something underground is connecting the structural footings to the surface supports. This is my personal opinion for reference only.
It’s a DCS system that’s been connected~~~