Double tap of the main breaker

Here is the issue. I called out a double tap on the main 200 Amp breaker. The main wires are aluminum (with protective coating) and the wires that double tap the main going to the sub-panel next to it are copper. I have a realtor that claims he has called a retired electrician and said it is not a normal practice but it IS acceptable. Can someone tell me how to word this so I can get through to the realtor that the retired electrician, he, or even me are set straight. Over 8 years I have never had an argument when I come upon this issue. So it’s a double tapped Main breaker with aluminum (with protective coating) and copper on the same screw (lug).

Give me a link, the NEC on it, or proper wording. Thanks

Unless the terminal is rated for more than one wire it is not correct.

If it violates the mfgs. listing, it’s wrong. Article 100

From the NEC:

Have them show you documentation that the lug is listed for two conductors.

110.14(A) Terminals. Connection of conductors to terminal parts
shall ensure a thoroughly good connection without damaging
the conductors and shall be made by means of pressure con-
nectors (including set-screw type), solder lugs, or splices to
flexible leads. Connection by means of wire-binding screws or
studs and nuts that have upturned lugs or the equivalent shall
be permitted for 10 AWG or smaller conductors.
**Terminals for more than one conductor and terminals
used to connect aluminum shall be so identified.

From Double tap SEC neutral lug - InterNACHI Inspection Forum

Thanks for the specifics guys.

Article 100 is definitions which included the Terms, listed and identified. :wink:

I was under the impression that aluminum and copper wires cannot be touching one another regardless. The retired electrician claims it to be okay as long as the protective coating for the aluminum wires was used (which it was used). Can you expand on that. By the way, great help on this one guys.

that is not the issue here.

Unless the terminal is rated for more than one wire, it’s wrong and violates it’s listing.

Indeed! :smiley: Just wanted a clarification that this is also an issue as one metal being weaker which will wear quicker and possibly create more issues. Can you expand on that whether I include it or not. Thanks all

Antioxidant paste may or may not be used.

The retired electrician is wrong unless the terminal is rated for more than one wire.

No need to even go there.

Tell them to supply the information for the terminal.

I bet they won’t. :wink:

I will do just that! :wink:

All good points and you can add comment #6 if you need to.