I am looking at modifying a control panel that brings a couple different systems together. There are two pieces of equipment that connect to the panel to give a general warning if either piece is in alarm. Each piece of equipment has its own 3 phase 480V feeder and its own 480/120V single phase transformer. The control panel takes 120V signals from both pieces of equipment and therefore I have 2 separately derived systems in the same panel.
Am I correct that their grounded conductors from the two pieces of equipment cannot be connected together? It would seem that it would cause the grounding conductor to carry current during normal operation so it would not be permitted.
Also, it looks like the grounded conductors would have to be identified by the system that they are connected to. So even though they are operating at the same voltage, would I need the grounded conductors to have different insulation marking to note the difference? They are 12AWG conductors. Or is it OK to have them both be plain white insulation but use wire labels to distinguish which system they are from?
Thanks
Am I correct that their grounded conductors from the two pieces of equipment cannot be connected together? It would seem that it would cause the grounding conductor to carry current during normal operation so it would not be permitted.
Also, it looks like the grounded conductors would have to be identified by the system that they are connected to. So even though they are operating at the same voltage, would I need the grounded conductors to have different insulation marking to note the difference? They are 12AWG conductors. Or is it OK to have them both be plain white insulation but use wire labels to distinguish which system they are from?
Thanks
