BryanG
Member
I hadn't thought about a ground loop issue because my devices are always in the local box, or on a chassis made of very large section highly conductive steel box. The chance of there being a potential difference on the earth is slim. I can see it for remote devices around a factory. However the question then is what if you have two screens or two devices that internally connect ground to negative. And it ties in to what I mean when I say unless you check each device you are creating an unknown system rather than a floating system. And if you think about what happens when there is a fault, you can end up with a lot of current flowing through the grounding cable, would you rather have it be a cable that you designed to carry that current or the one that was just big enough to feed the HMI.