Can't tell if its 12 or 10 AWG

I am in a situation here.

The conductors going into a 30 amp breaker looked to be 12 AWG. Although, it is real hard to confirm without unscrewing it. I compared to my sample 12 AWG and it looks the same but 10 AWG is very close. How should I write this up without making a mistake one way or the other? Thanks


If you are not certain of the wire size I think you’d have a hard time justifying writing it up.

What is this circuit feeding? It may very well be fine, even #12 on a 30A. Could be an A/C circuit.

What is the circuit for?

I couldnt find the appliance, resistor on the circuit, it was labeled kitchen/living room receptacles and lights which it wasnt. I tested all the electric baseboard heaters with the breaker off and they all worked. I am thinking it might be hot water tank but not sure, exactly. No A/C in home.

You can certainly call it out if you can confirm it being #12. Other than an A/C it is likely not correct and should be looked at.

It is on a double pole breaker, so it is 220V at least. Any chance it is running to a well pump?

Do you normally trip breakers during your inspections?

No, absolutely not, I know I went beyond the standards and I had permission from homeowner.

Cool, Just checkin’ :mrgreen:

Be honest and say you cannot determine if it is the proper size with out removing it and suggest further evaluation.

Thanks everyone :slight_smile:

You can always defer it for further eval stating that it does not appear to be of proper size…this way, the electrician comes in and either verifies it as correct or incorrect…either way, you’ve pointed out a possible concern and you’re covered.

You should have the electrician check out the bleu wire I know in the North Americain side the bleu is genrally a phase conductor but other hand in modern Europe colour code the bleu is used for netural conductor.



I usually compare the wiring to others in the panel. You’ve got other 12 AWG’s in there.

That particular wiring does not stand out as a defect.

Just write it up as being improperly labeled (wrong), and that you can’t confirm the wire size-- have an electrician go from there. There’s almost always other work that an electrician needs to touch up anyway’s.