Is This OK?

The photos are of an older Square D panel. The SEC’s are double tapped copper and stranded aluminum.

  1. Are the double tapped SEC’s acceptable? (I think not)
  2. How much worse is it that it’s coper and aluminum?
  3. How serious is of a deficiency is it?

Definitely not OK. The cooper and aluminum together makes it even worse than if it were two of the same conductor material.

NEC 110.14 prohibits the use of conductors of dissimilar metals in the same terminal or connector unless the terminal/connector is identified as for that purpose.

I would write it up as unsafe with recommendation that a qualified electrician assess and repair as necessary.

Back in the day we used connectors that had a plate between the dissimilar metals and would also use Penetrox. It has been awhile so if any one still doing electric work knows any different please feel free to correct this.

The dissimilar metal is kind of a moot point.

Did you do a scan of that 100 Amp breaker it looks like it was over heated?
I also agree with Robert of course.

Thanks guys.
BTW, I did scan it with my IR Thermometer and it was ok.

  1. No
  2. Having both copper and aluminum significantly aggravates the condition because copper and aluminum have different thermal expansion coefficients.
  3. Enough that it ought to be corrected

:)Thanks George:)