Use Of Materials

[J Phillips Electric Inc]

Electrical Contractor Here asking the question: Does the NECA not allow a 12/2 Romex conductor to be terminated on a 15-amp breaker? We pulled 12/2 as home runs in a residential home and our local inspector says we can't put that conductor on a 15-amp breaker. Says it must go on a 20-amp breaker because the wire is rated for 20 amps

 

[hbiss]

We pulled 12/2 as home runs in a residential home

So, you have #12 as a home run feeding #14 for the receptacles and lighting? Perfectly fine, done that myself. How can you use 20A OCP when it feeds #14???

-Hal

 

[zbang]

We pulled 12/2 as home runs in a residential home and our local inspector says we can't put that conductor on a 15-amp breaker.

They're quite wrong. As long as the wire is protected at or below it's rating, you're fine. (Want to put a 6g on a 20a breaker? Go for it.) You might have to remind them about up-sizing for voltage drop issues.

 

[Little Bill]

So, you have #12 as a home run feeding #14 for the receptacles and lighting? Perfectly fine, done that myself. How can you use 20A OCP when it feeds #14???

-Hal

Where did he mention feeding #14?

 

[infinity]

We pulled 12/2 as home runs in a residential home and our local inspector says we can't put that conductor on a 15-amp breaker. Says it must go on a 20-amp breaker because the wire is rated for 20 amps

Inspector is in correct and is IMO pretty clueless to think that the conductor has to match the OCPD size.

 

[NEC Inspector]

Inspector is totally wrong. What you have done is just "extra safe".

 

[augie47]

Your original post mentions #12 as "home run".
Did #14 ever enter into the picture >?

 

[Little Bill]

Your original post mentions #12 as "home run".
Did #14 ever enter into the picture >?

I asked hbiss the same question?

 

[hbiss]

Your original post mentions #12 as "home run".
Did #14 ever enter into the picture >?

We pulled 12/2 as home runs in a residential home

Maybe I'm being nit picking but he pretty much implied it.

Upsizing a home run is commonly done and a reason for his using a 15A to feed it. If the entire circuit was 12, why wouldn't you just use a 20A? No, you don't have to, but kinda a waste of money and effort because if the rest of the circuit

-Hal

 

[Joethemechanic]

They're quite wrong. As long as the wire is protected at or below it's rating, you're fine. (Want to put a 6g on a 20a breaker? Go for it.) You might have to remind them about up-sizing for voltage drop issues.

Yeah long ago we ran #6 aluminum on an overhead service to an outbuilding for a 15 amp circuit just for voltage drop. I forget exactly how far but at least 200 if not 300 feet

 

[hbiss]

Would be nice if the OP came back and settled the argument. I have a beer depending on it.

-Hal

 

[retirede]

Would be nice if the OP came back and settled the argument. I have a beer depending on it.

-Hal

Don’t wait….go ahead and drink it!

 

[infinity]

If part of the circuit is #14 NM cable why would the inspector say to use a 20 amp OCPD?

 

[hbiss]

If part of the circuit is #14 NM cable why would the inspector say to use a 20 amp OCPD?

That's the question. I could imagine that he saw #12 and wondered why it wasn't 20A. Many inexperienced guys when changing panels especially, automatically assume that a #12 in the panel must be 20A, the #14s 15A.

-Hal

 

[Eddie702]

IMHO the entire circuit should be the same size wire, unless it is done for VD and splices made at the beginning and/or end for smaller wire to connect to the breaker etc. If changing a panel your not going to search the entire house to look for problems. Unless its a motor or HVAC load it gets the 15A for 14s, 20A for 12s and 30A for 10s Unless you find a smaller breaker on a circuit you keep it that way

If the inspector is insisting on a 20A breaker on #12 he is wrong

 

[infinity]

IMHO the entire circuit should be the same size wire

There is not requirement to do that but no one says that you cannot do it. Someone changing the panel should check to see which conductors are on the existing breakers and mark them accordingly.

 

[Eddie702]

There is not requirement to do that but no one says that you cannot do it. Someone changing the panel should check to see which conductors are on the existing breakers and mark them accordingly.

Agree I was just stating my opinion.