06-12-2021 09:50 PM
I am trying to operate a compact-RIO 9054 at elevated ground potentials (150kV+). I have configured the system as shown in the schematic. I however have some question on the operation of the crio.
1. Is this safe to operate (in terms of the hardware)? I have had shorts between the casing and the PCB at high potentials (~20kV) causing equipment failure.
2. What is the highest operating voltage of a CRIO unit? Can apply high floating voltages if the -VCC is tied to the floating ground?
06-14-2021 02:53 AM - edited 06-14-2021 03:04 AM
The common voltage niveau is not the problem here as long as you can guarantee that there is absolutely nowhere even a high impedance connection to anything else referenced to a different ground potential. Those creep paths are your problem.If you can avoid them or fully keep them unter control things should be fine. It does require that your floating common “ground” never can get loose anywhere. Any equipment not very well referenced to that ground but connected to anything that is, is at great danger!
The cRIO hardware only can withstand about 1.5 or 2kV potential difference between the isolated IO modules and the IO modules and the chassis. That simply means that you can’t really use this isolation in any way and need to make sure all of that is safely referenced to your high potential “ground”.