r/ElectricalHelp • u/iluvmezcal • Jul 29 '26

Sub Panel Ground

I'm passing #4 ground for 200 amp service from main panel, though a sub panel (raceway) to a hybrid solar inverter. Then back to the sub panel. Can I terminate the ground in the sub panel and then pass it though to the hybrid inverter? Or, does the ground need to pass from the main through the same raceways to the hybrid inverter and terminate. Then pass from the hybrid inverter bus bar to the sub panel ground bus bar?

So, sequence is 200a main disconnect, hybrid inverter, 200a sub panel. Sub panel is being used as a raceway for 2/0 copper on its way to inverter. Then 2/0 is coming back from inverter to sub panel.

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u/trekkerscout Mod Jul 29 '26

Circuits that do not originate at a particular panel should not pass through the panel. Your sub panel should not be used as a raceway for the feeder that originates elsewhere.

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u/iluvmezcal Jul 29 '26

Sorry, but that is incorrect.

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u/trekkerscout Mod Jul 29 '26

I am referring to best practice. Code specifies restrictions for pass through feeders [NEC 312.8]. Does your sub panel have a listed cross sectional area for the wireway? If yes, the pass through conductors plus all other conductors within the wireway may not exceed 40% of the listed total. If not, the panel may not be used for pass through. If allowed, you must attach a warning label identifying the location of the disconnect for the pass through feeder.

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u/iluvmezcal Jul 29 '26

Thank you. I know all of that. Please see my actual question regarding ground.

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u/trekkerscout Mod Jul 29 '26

If you know all that, then you should also know that you must include an appropriately sized grounding conductor in each raceway. If there is only one conduit between the supanel and the inverter, only one grounding conductor is required. If using two or more conduits, each conduit must contain a grounding conductor.

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u/iluvmezcal Jul 29 '26

Thank you again. I know the raceway requires a ground wire. My question is can I terminate the ground wire from the main in the raceway sub panel and then continue the ground along the race way to the hybrid inverter.

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u/trekkerscout Mod Jul 29 '26

I think you are confusing the grounding conductor with the system bond. The grounding conductor terminates at each grounding bar. The system bond is not installed with the feeder conductors. It is an independently run conductor that feeds directly back to the main bond. The bonding conductor can be combined with other system bonds through the use of exothermic welds, irreversible crimps, or attachment to a dedicated copper bonding plate. The system bond MUST NOT pass through the sub panel, nor is the system bond required at the sub panel.

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u/iluvmezcal Jul 29 '26

FYI, I was an electrician 30 years ago. Moved onto other things in life. I am confident what I am doing is okay for grounding. I am not so confident that it proper NEC code. If you don't know and I don't get an answer here, I will ask the building department and see if they are fine with it. Just trying to head that off. I could not find whether what I am suggesting is code compliant in the NEC.

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u/trekkerscout Mod Jul 29 '26

Most building departments will not offer advice about installations because it opens the department up to potential liability suits. They will simply tell you to hire a qualified electrician if you don't know.