two neutral wires under one lug

What are the hazards associated with having two neutral wires under one lug on the bar? I understand NEC says no, but what is the rationale behind it?


Here you go:

Very good Larry

Exactly what I was looking for. Thanks Larry.


Glad to help…

I almost never see a panel without that issue.

that and neutral sharing a lug with ground is common too


I think that a neutral and ground can share the same lug in a main panel

No they cannot. The NEC clearly states that each neutral must terminate by itself in the lug.

In a service panel they can share the same bus.

No, but t can share the same buss.

So in your opinion when an inspector sees a 15-20 year old panel with A ground and neutral under the same lug, (before it was NEC code), and that’s basically the only thing wrong, should we report it as a defect?

I know that manufacturers have always required each neutral terminate under it’s own lug, but the code is not that old, and many older electricians terminated a grn/n under same screw.

This is an honest question.

This was a code requirement before also under the 110.3 rules that things be installed according to the instructions. Since many do not read those it was added as a standalone requirement to the NEC. IMO it was wrong then as well as now.

I see it a lot in my area in homes especially in the 1995 - 2005 period.

I always call it out.

I’m also sure few have it fixed.

I thought 2 neutrals under 1 lug is a bigger issue only if both wires are not the same size.

Nope. Read and save this document for future reference.

As mentioned from a code perspective it’s not permitted, from a theoretical perspective it’s probably not a problem if they’re the same size.

Thanks Jim. I’ll keep reporting it. There are a few inspectors in my area who say nothing is wrong with it.

Note: 110-3(b) The instructions in a panel board may allow multiple wire terminations on a neutral bar terminal. However, most panel board manufacturers only allow multiple equipment grounding conductors in a single terminal.

If two neutrals are under one lug and you only switch off one circuit breaker the second circuits return path will remain energized causing a dangerous hazard if contact is made by the electrician or arcing if the neutral wire comes in contact with any grounded parts of the panel.

Have you ever seen a panelboard that allows two conductors under the screw of the neutral bar?

At this point what difference does it make!?!

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