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I havd a disconnect at meter which supplies a panel about 70 feet inside building. I upgraded the system based on comments from a previous question. At the disconnect, when I add the neutral conductor (green wire), I disconnect the wire that ran from the neutral to the case of the disconnect. So now my question occurred to me as to whether I should bond he neutral and ground at my new panel or reconnect my ground to case at the disconnect??

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    Green conductor is safety ground, not neutral. Grounding = Green or Bare = always bonds to case, only carries fault current. Grounded = Neutral = Gray or White = Only bonded to Grounding at one point, normally carries current. Your description leaves questions about what you have done. Please edit to add some clear pictures.
    – Ecnerwal
    Mar 31, 2021 at 15:46
  • @Ecnerwal You type fast.
    – JACK
    Mar 31, 2021 at 15:53

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If you have EMT, IMC or RMC metal conduit run all the way from the disconnect to the subpanel, then you can use that metal conduit itself as the grounding path, and no ground wire is needed.

Otherwise, you need to have run 4-wire cable (or 4 wires).

Sean Connery rule applies.

"There can be only one" bond between neutral and ground.

First, get your colors straight. Neutral is not ground.
Neutral = white or gray
Ground = green, yellow/green striped, or bare (that's true 'round the world).

Neutral comes from the utility. It exists in all places.

Ground is created, by you, at the very first disconnect past the meter. In that location you:

  • Establish a Grounding Electrode System (grounding rods)
  • Have a "ground bar" bonded to the metal frame of the disconnect
  • Bond neutral to ground, in this one and only place
  • Carry neutral and ground separately everywhere else.

Since neutral and ground are bonded here in the main disconnect, you can actually use the same "bar" for both neutral and ground. It's not my favorite way to do it, though. I prefer separate, isolated bars, and the fattest wire you can get as a specific neutral-ground bonding wire. The reason is, so you can put a clamp ammeter around that wire which is handy for troubleshooting a variety of problems.

As a practical thing, the meter pan itself also gets grounded because you use EMT, IMC or RMC Metal Conduit between meter pan and disconnect. Once had someone try to use PVC... they couldn't find a way to ground the meter pan. Golly!

Neural and ground are carried as separate wires

At the subpanel, place the white neutral wire on the neutral bar.

Place the green or bare ground wire on the ground bar (or rely on the metal conduit).

Any subpanel must have neutral and ground un-bonded. Can't bond it here; that would be two bonds!

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  • Thanks .. sorry for the green colored insulation. It was all the supply house had in stocks. Otherwise, I would have used white for neutral. So I think I need to reconnect my wire from neutral lug in disconnect to the case of the disconnect and not bond the subpanel inside. ??
    – Herb1960
    Apr 1, 2021 at 15:27
  • @Herb1960 Yeah, shortages. But you can't just leave it green! You have to get some white tape and wrap it in a spiral so the wire looks white. If the wire is #4 or larger, you are done; that is Code compliant. #6 or smaller it's good for temporary but you need to get real white wire when the shortages abate. Also, is there a separate actual ground wire (green or bare)? Apr 1, 2021 at 18:06

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