Arcing At the Breaker

Something I wanted to share with the forum.

During the electrical panel inspection today I noticed evidence of scorching on a 40A breaker.

When the A/C kicked on, you could see the arcing happening as well as hear a very faint click sound. The orange in the photo is the arching. It didn’t do it every time the A/C compressor kicked on, we were lucky to see it and grab a photo of it.

Yes, the main was double tapped :roll:

Most likely a loose connection…

I would agree with Jeff. Its probably just a loose connection of the breaker. Aluminum wiring, or any wiring for that matter tends to do that with thermal expansion cycles probably because it was not torqued down properly.

Actually - This you are referring to is CREEP and was very common in the older late 60’s early 70’s style of AL compounds. The general issue is termination and since 99% or possibly 99.9% of the installers do not, or do not have a torque screw driver or wrench then chances are original termination is either over or under torqued- which are both problematic.

The arcing due to load termination is common in both CU and AL in modern wiring, again due to the fact installers ignore the torque requirements. Fact - when you use your ELBOW torque wrench you tend to over torque which stresses the metal, in AL when you flex it, it hardens and tries to conform to original state which can alter the termination…similar to CU but less noticeable because AL is a softer metal.

At the end of the day an improper torque is more to blame than the material being used as the conductive body for electron flow.

Thank you for clearing that up Paul!

We tend to make things up as we go along, like aluminum is bad.
It’s not what it is, it’s how it’s being used and installed.

All electrical components tend to do that with thermal expansion cycles!

“Aluminum wire tends to fail from corrosion”

Wire fails from arcing.
Arcing results from corrosion.
Corrosion results from excessive temperature that accelerates the corrosion process.
Excessive temperature is the result of improper torquing during installation.
Improper torquing is the results of improper training.

It’s not about what the wire is made of, it’s inadequate training.
Report it accordingly.

Improper reporting is also the result of inadequate training…

Inadequate training is the results of relying on inaccurate information from an Internet message board.

Verify your source.

I agree with everything you said above. I should have elaborated on why it was probably doing this and that aluminum wiring, or any wiring for that matter tends to do this when improperly torqued. David, I understand that copper wiring will also do this with thermal expansion but I have seen it far more commonly with aluminum wiring which is why I gave a generic answer. The generic answer was bad on my part and I will try to be more thorough with my opinions in the future.

It’s all good fella…in my opinion that is exactly what a message board is all about…to ask, learn, educate and make friends in the business…

I learn something new everyday…this is why i share so others will not have to take the journey…they can some straight to the top of the mountain:mrgreen: