I had the following setup for a room, running on 15A breaker with 12/2

enter image description here

I wanted to add an outlet in the attic above this room so I did this:

enter image description here

There was enough slack in the wire, so I added the outlet in a plastic (blue) junction box and outlet using the existing wire from the breaker.

Should I have done it the way depicted in the image below? (Add yellow line)

The reason I didn't is because the junction box labeled '1' would have been overstuffed with wires, not to mention that I would have had to run an extra wire.

But I can't help but think I was supposed to do it this way.

Is what I did fine? I realize I should have asked prior...

enter image description here

  • 5
    The wiring looks fine but your drawings contain bothersome optical illusions ;)
    – JimmyJames
    Oct 11, 2017 at 18:14
  • Out of curiosity, was the wire in the attic not stapled down? When I've needed to do this everything was so tight and there was no slack at all.
    – JPhi1618
    Oct 11, 2017 at 20:46
  • It was stapled, It was close but over the whole run I was able to get enough slack out of it.
    – Matt
    Oct 12, 2017 at 0:49
  • The only problem that could arise is the break could start tripping depending on how many amps all devices you are trying to power consume.
    – cybernard
    Oct 12, 2017 at 2:55

2 Answers 2


What you did is just fine. That is what any experienced electrician would have done.

If all of the wire in the entire circuit is #12 you could change your breaker to a 20 amp breaker for more capacity. If any of it is #14 you have to stick with the 15 amp breaker.

The previous setup is a waste of wire. They could have put one junction box in the middle of the room and dropped to each box OR they could have hit one box and then daisy chain to the other three boxes through the studs if the room only had one door.

There are many ways to get the job done and sometimes it is just a personal preference.

Your setup is fine though. Good luck!

  • 7
    OP said 12/2 - they didn't necessarily say 12/2 copper. If it's aluminum wire it needs to stay 15A (and the connections to devices should be pigtailed to copper with anti-ox dope).
    – J...
    Oct 11, 2017 at 20:38
  • The way OP did it also probably helped avoid box fill violations in box #1.
    – GManNickG
    Oct 17, 2017 at 22:04

Yes, that's a perfectly fine way to do it, provided you really have enough slack to bring the cables into the box with the legally required lengths.

It also helps to use a 4x4 box or even a 120mm box as this gives you a little bit more useful length on the wires.

Wiring in North America is a tree topology. There's nothing wrong with a linear "vine" topology like an awful lot of receptacle circuits, but having a node somewhere with branches going in several directions is fine, and saves wire.

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