Ground and Neutral under same lug

Specific Inspection Topics Electrical Inspections
1

OK , yesterdays inspection , I had a ground and a neutral from the same circuit under one screw in the Main Service Panel. Is this ok ? First time I have seen this, usually grounds and neutrals are separated .

Thanks in advance , Rick

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2

That’s funny because I see this almost daily. No, they should be separated.
here it what I write.
Neutral (white wire) and equipment grounding conductors (bare wire) terminate under the same lug. An individual terminal should be provided for the connection of each branch-circuit neutral conductor. When the neutral is disconnected, the objective is to still have the equipment ground connected. If both the neutral and grounded conductor is under the same terminal, this cannot be accomplished. Recommend repair by a licensed electrical contractor.

2 Likes
3

Although this was a common practice for decades (especially when panelboards didn’t have enough terminal holes) it has never been permitted. To make that point even clearer the NEC added this to the wording in the code:

4

Not allowed, one neutral per hole, you may double up on grounds provided instructions (panel labels) say so.

Is this panel GE? I see it frequently in older panels, Square D QO is the biggest offender followed by GE where those panels had limited neutral terminals to start with so doubling up was very common.

The reason behind not allowing doubling up (among isolating circuits) is that one conductor may be held in place more by the screw than the other conductor. This can cause further loosening and overheating down the road.

5

Which would be correct Martin :wink:

The actual code being>

But the thing is, it was not always in the NEC .

I’m too lazy to look, but i want to say 3-4 code cycles or so

Which means older installs are compliant , under the cycle they were wired

This is an important point because older gear usually doesn’t accommodate what newer gear would.

~S~

6

Thank you Gentleman ! As always , I appreciate you sharing your knowledge!

7

Not exactly, this was already prohibited by the listing of the panelboard. It was only added to the 2002 NEC because no one actually knew about the listing violation.

8

Here’s the original ROP for that language to be inserted into the NEC for anyone interested, this was later moved to Article 408 when they reshuffled the Article numbers in the 2002. The substantiation provided by Square D is worth reading.

9

You are indeed be correct.

If I may, and I know I can be wrong, most older panel boards disallowed it via labelling rather than code; but I may have to double check that now.

Thank you for peaking my curiosity! :smiley:

Edit: Robert, thank you for the ROP quote. That is exactly what I was thinking of but could not find it.