I'm replacing a few of the receptacles in a room. 3/4 have been straight forward: 2 black wires, 2 white wires + ground. Was able to do a one for one swap with the new receptacles.

The 4th one has a ground, 2 white wires and 3 black wires. Looks like it was installed with 2 of the black wires going to the same screw.
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My new receptacles are these:
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Since the new ones have both a screw and a slot (sidewire and quickwire) could I just put one of those 2 black wires in the screw and the other one in the slot?

Bonus question, the previous wiring had both white wires doubled up on the same screw, can I just split those in the new receptacles and just have 1 on top, 1 on bottom?

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    Cables come in black + white, not "just black". Trace each black and white - 2 whites and 2 blacks should = 2 cables. That leaves one black left over - find where it goes and let us know where the white wire from that cable is going. Commented Nov 25, 2021 at 19:34
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    Placing two wires under a screw is usually a big no-no(unless a clamp type screw). Those slots/quickwire/back stabs have a bad name since they can cause problems. What you can do is use wire nuts/wire connectors and pig tail the wires meant to be together with a short wire to the receptacle screw. The two screws are electrically connected together if the removable tab is still there, so one wire on each screw is connected to the other.
    – crip659
    Commented Nov 25, 2021 at 19:36
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    @Guest89 That is a wire nut, quite common in North America, think Europe uses something like wagu connectors, both will do the job well.
    – crip659
    Commented Nov 25, 2021 at 20:57
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    Wire nuts are very cheap and have the different types of wires you can put in them on the package. Get the ones for 14 and 12 gauges. Think it is three 14 or two 12 and one 14 for the yellow ones. It is marked on the package. Size of the breaker is important, 20 amp breaker must have 12 gauge wire(or bigger), 14 gauge not allowed on 20 amp breaker circuit.
    – crip659
    Commented Nov 25, 2021 at 21:53
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    Most yellow wire-nuts can handle 3 each 12 awg wires it is best to check the specific brand and type for the listing instructions both 3m and ideal the 2 leading mfg of wire nuts used in the U.S. the yellow “wing” style can handle 3 ea # 12 and 4 ea #14 , This s the standard that inspectors use and if you have a “special” purchase from the internet that is not listed and the inspector catches ouch.
    – Ed Beal
    Commented Nov 25, 2021 at 22:25

2 Answers 2


First, I don’t use the backstabs, the quick wires holes you mention that you push wires in to. My personal belief is that they should be outlawed because of all the failures I have seen.

You ask if you can use both the screw terminals and the back stabs. Yes, it is code compliant with 14 awg wire. 12 awg should not fit in the backstabs. Backstabs are only rated for 14 awg wire, which should have a 15A breaker.

A better way to make the connections would be to add a 4th wire if 14awg and a wire nut. The extra wire then goes to the receptacle, this is called pigtailing and is a superior method to using the backstabs. Then only 1 wire to the receptacle. This the method I have used for my career.

Another method is using a device called a lever lock, they are newer and I believe for DIY they are even superior to wire nuts. Lever locks are rated for both 14 and 12 awg wire.

Lever locks cost more but are really easy to use:

  • strip the wire
  • open the lever
  • slip the wire in and close the lever and it is locked.

You need one for each wire, and they come in 2-6 hole versions. They take no real skill to use and for that reason I think they are a better choice for most DIYers. I started using them on lighting fixtures about 6-7 years ago.

  • I totally agree with wago's. With other types of connectors it's easy to get it wrong. With wago style connectors there's only one thing that matters, and it's that you remove the correct length of insulation (12mm / 0.5"). Apart from that it's impossible to get it wrong.
    – vidarlo
    Commented Dec 4, 2021 at 18:42

Because that's an el cheapo receptacle. They only provide screws, and backstabs for #14 wire. Backstabs are unreliable.

Buy a spec-grade receptacle for this location. They are $3 instead of 60 cents, are better built, and provide facility for 2 wires under each screw, or 4 wires per side. Read the instructions for how.

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