I'm swapping out outlets and this one has me stumped. This is in a room of switched outlets (top outlet is always hot, bottom is switched) so the red/black side tab on each outlet is broken off. The white side is not.

I was working on this outlet which is a bit of a mess. There are 3 whites, 2 reds, 3 blacks.

I've been getting in the habit of switching the wires out one-for-one, so I first take off the blacks, put them on the new outlet, then the reds, etc, so I can replicate the original wiring.

What has me stumped here is that I appear to have two separate circuits connected together in the same box.

Here's a shot of the 'leftover' tips of the white wires in the old outlet:

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as you can see they were all connected to one side and the tab was not broken. Am I correct in assuming this is essentially a pigtail (all wires connected together)?

Because what is confusing is...

enter image description here

...of the 3 whites you see coming out of the box, the leftmost and rightmost are 'hot' on two separate circuits. The center is not (so I assume this is a branch line to other outlets).

Does it make sense that I'd have two circuits coming into one outlet joined together like this?

Am I okay connecting these together on the new outlet or do I have some serious wiring issues here?

I should clarify the '2 circuit' issue. I have to turn off two separate circuit breakers to make sure all the lines are dead in this outlet. I've also found a second outlet (in the same room) wired up the same way--I need to kill two circuit breakers to make sure the hot wires are off.


1 Answer 1


It just seems like you have two 3-wire cables (with constant and switched hots) going into and out of that box, along with a 2-wire constant feed. It's not two circuits. The reds are switched and the blacks are constant hot.

IMO I would pigtail each color and use the side screws on the receptacle just like they were before.

That looks like #12 so you can no longer use the backstab/quickwire holes in the back of receptacles (in the US at least).

  • The thing is that I have to shut off TWO circuit breakers to make sure all the lines are dead on that outlet. That seems to me that there's two circuits going into it? (and yes, I'm not using any back-stab connections on the new outlets--all proper pigtail (if needed) to screw posts.)
    – DA01
    Commented Jul 19, 2014 at 0:21
  • 1
    It could be that there is a multi-wire circuit there, and when you disconnected the whites you are getting a backfeed, which is why you have to shut off two breakers, and why now a two-pole breaker is required for those. It's hard to say without knowing exactly how it's wired. From the pics it looks like a typical half-switched setup. Commented Jul 19, 2014 at 0:43
  • Yep, it's definitely half-switched. I can confirm that. I need to read up on backfeed, though. That's a new concept to me. So, if that's the case, am I OK wiring everything back up the way it was with the new outlet?
    – DA01
    Commented Jul 19, 2014 at 0:46
  • @DA01 No, if it is a multiwire branch circuit the breakers should be on a two pole breaker ( there would be 220v between the red and black wires if done correctly ). If it isn't, then you have a real mess that will take considerable time to fix. Go and check if one of the breakers has a red wire attached to it; which would tell you it is a multiwire branch circuit. Commented Jul 22, 2014 at 1:08
  • 1
    @DA01 Hah. As to why, these are human beings we're dealing with, here... ;-) Commented Jan 19, 2015 at 5:43

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