Changing wire size

[wireday]

I want to re-purpose a #10 home run circuit. Can I put #10 onto a single pole 20amp breaker? The #10's run from the panel up to the attic about 20 feet total. Then I want to junction onto the #10 with #12 and run another 30 feet to a receptacle.Thanks

 

[LarryFine]

This is okay. It wouldn't hurt to find a way to tag the wire stating that there is #12 and to not use more than a 20a breaker.

 

[charlie b]

Agree that you can do this. But you will need to make sure you have a #10 EGC, at least to the point where the 10 and 12 meet.

 

[PhenixFord]

I've "stepped" wire size due to voltage drop this way. I don't recall any rules about limiting the amperage?

 

[wireday]

Thank you, Not sure why it was originally done this way,There are three circuits all together in the same EMT. They do share a #10 EGC. I know they always have been on the 20amp breakers.

 

[LarryFine]

I've "stepped" wire size due to voltage drop this way. I don't recall any rules about limiting the amperage?

Well, you're limited at the ampacity of the smallest conductor.

 

[infinity]

Thank you, Not sure why it was originally done this way,There are three circuits all together in the same EMT. They do share a #10 EGC. I know they always have been on the 20amp breakers.

Could be for voltage drop. This is done all of the time.

 

[PhenixFord]

Well, you're limited at the ampacity of the smallest conductor.

Yea I wasn't planning on going there.

 

[wireday]

Could be for voltage drop. This is done all of the time.

Yes, but this is only twenty something feet.

 

[wireday]

Well, you're limited at the ampacity of the smallest conductor.

Thats fine, I only want the 20amps

 

[PhenixFord]

Yes, but this is only twenty something feet.

Quite possibly, he ran out of #12 wire. And he knew that the #10 was fine. ????

 

[augie47]

Quite possibly, he ran out of #12 wire. And he knew that the #10 was fine. ????

my first though also.. "all we had on the truck"