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I'm building what is essentially a rack of power supplies to be used as a testing unit for an ion propulsion system. One of the requirements is some pretty high voltages, namely around a 1250V difference between some of our optics. However even at the high end we need a few different rails for a number of functions. In order to achieve this we are essentially connecting a couple of power supplies in series. However this leads to an issue where some of the smaller (output voltage) supplies that are essentially tacked on to the large ~1kV supply don't have a sufficient output to chassis ground isolation rating(600V). In order to get around this we are powering these supplies through an isolation transformer and encasing them in an insulating box to isolate them from the rails of the rack.

However while doing this we still need to be able to control/interface with the power supplies via LAN/Ethernet. I was able to find some information about ethernet galvanic isolation but was having trouble determining whether the isolation rating was for AC or DC and whether or not this application would be fine as is or if we would need to add some additional isolation transformers on the line to ensure the safety of the connection.

Simplified Diagram of the setup

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  • \$\begingroup\$ I'm sure you have your reasonst for your solution instead of using a high voltage power supply. Just keep in mind that you're creating a lot of known and unknow dangers for all the peole around this system. \$\endgroup\$
    – kruemi
    Commented Jul 8, 2022 at 10:24
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    \$\begingroup\$ The issue is that we need 3 different rails that are all ~1kV at different voltages and getting 4 supplies at 1kV+ and up to 15A is outside of both our budget and our capacity to power with the power setup at our facility. We definitely plan to take as many precautions as possible regarding the voltages and floating potentials involved but this is pretty much the only way that I could figure to do this with our constraints \$\endgroup\$
    – Dhruv Goel
    Commented Jul 8, 2022 at 15:24

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This sounds like a great use case for fiber optic networking. You can run an Ethernet/fiber converter off the same isolated 120V as the power supply, and get much more certainty about adequate isolation between the control computer/network and the high voltage, since the entire fiber is non-conductive.

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  • \$\begingroup\$ Yeah this seems like the way to go. I haven't been able to find any definitive information about the isolation native to ethernet with regards to GPD/floating equipment. Was hoping to avoid the added expense but I'm just gonna have to bite the bullet \$\endgroup\$
    – Dhruv Goel
    Commented Jul 8, 2022 at 15:26

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