What is the best (or correct) way to wire outlets in the middle of a circuit?

1) Using the screws available in the outlet to "extend" the circuit wires to the next outlet.

jumper wiring

2) Making a derivation from the wires to the outlet.

derivation wiring

We also have here derivation connectors that look like those, but the take a lot of space in the recepctacle box:

derivation connector

The outlets we use here have this kind of connection screws

outlet screws


When wiring multiple outlets on one circuit, whether splicing or chaining is the better way depends on whether your devices are made to be chained.

If you are using North American type devices, your second illustration is the best way, even though it requires the two wire nuts (or other splice connectors) ("splice"="derivation"). It is not good to rely on the tab or other connections inside a N. A. device.

If you are using devices like the one in your fourth picture, then you do not normally use splices. For the middle outlets, you can use the two wire positions on each terminal to chain the outlets together, similar to your first picture.

I live in the U.S. but I have seen pictures of switches, outlets, and ceiling light rosettes from the U.K. and Australia that have multiple screw terminals electrically joined, and are made to be chained. Some outlets used in the U.S. look like they could be chained, but they're not really designed for it and often fail in ways that are difficult to diagnose.

Your first illustration is correct for the kind of outlet shown, which seems to be a GFCI protected outlet. These usually have two screws labeled "LINE" and two screws labeled "LOAD". These labels are not shown in the picture but I guess the top screws are the LINE and the bottom screws are the LOAD.

| improve this answer | |
  • I can't add pictures in the comment, so I edited my post so that you can see how the outlets here are. Most of the them have a single screw per type (one screw for line, one for neutral, and one for ground). So when you tighten the screws you tight both line/neutral/ground wires at the same time. – Luiz Borges Oct 28 '16 at 20:32

Te first illustration is a fine way to do it - use the features in the receptacle for that purpose. I'm not sure if that's what I'm looking at in the third photo, it looks like each screw is designed to bind 2 wires, so that would be for that.

You can also "pigtail" the connection - splice the two wires (line and load) with a third short wire to the receptacle proper.

You MUST pigtail grounds in North American practice. If your circuit is a Multi-Wire Branch Circuit, you MUST pigtail neutral. The idea with this mandatory pigtailing is that the ground (and neutral) are not broken if the receptacle is removed from the circuit. Not breaking neutral is important for MWBCs.

In North American practice, tapping a through-wire as in your #2 pic is not allowed. Each wire entering a box must have at least 6 inches (150mm) of "tail" sticking out into the junction box. A couple ways to solve that problem. One is put TWO junction boxes at least 18" apart, cut the cable halfway between, now each box has the tail needed, then add a new section of cable between boxes. Another is the same thing, but instead of the second junction box, use the new Tyco "legal behind drywall without a junction box" Romex splices instead of one of the boxes.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.