Regarding grounding, there’s a rather strange thing to say.
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I’m using a pressure sensor powered by a PLC; the housing is always charged, and there are large fluctuations in voltage – I just can’t figure out what’s causing it. I finally found it today: to clarify, the power supply for the PLC is at location A ； The power supply for the computer monitor is at point B; it’s not on the same power strip ； I thought it wasn’t a problem, but today I realized that if the monitor’s power supply isn’t connected, the sensor won’t be powered! ! Later, grounding the power connector of the monitor fixed it. It seems the two are quite far apart, so it should be fine. Please don’t laugh at me; those who understand could please explain it to me.
I believe that one cannot simply consider the spatial distance between point A and point B; rather, it is necessary to look at the electrical connections between them within the power distribution system, such as whether they are on the same circuit and whether there are common wires.
Is it the sensor housing that is charged, or the computer monitor housing? It’s common for computer casings to become electrically charged; grounding it solves the problem. The slight charge on the sensor housing may be caused by interference voltages absorbed by the cable’s shielding layer; the solution is to ensure that the other end of the cable’s shielding layer is properly grounded.