Wiring an Outlet with Multiple Sets of Wires

It's a common question that we get on the channel when we're showing how to replace a receptacle .

And there's multiple sets of wires coming within that box .

Some of the viewers are confused on what's going on .

I , I know one sets coming in obviously to power the receptacle .

But why is there two or three sets within this box ?

And how do I properly replace a receptacle in the place of the old one I removed ?

Now ?

Sometimes it's straightforward and it's a 1 to 1 swap .

But let's go ahead and review just the highest level what each set of these wires is doing to give you that baseline understanding .

Then we'll go ahead and walk through a few different scenarios .

The first one is just the standard commercial grade duplex receptacle .

This one , you could tactically wire all three of those sets in the backs .

But should you ?

And what options do you have ?

The second scenario would be if we're replacing it with a G F C I .

Now , in that case , you need to know which set is your line and which set or sets is your load .

We'll talk , talk about that .

A little bit more .

And then the last one we'll talk about is something like the smart device which has built in USB C ports .

In this one , you only have a single screw terminal for hot , which is signified by the gold screw .

And then the silver screw would be your neutrals .

You could only take a max of two wires on each of those screws .

So in this case , we're going to need to do something different because we have three sets of wires coming in before we dive into those three different examples .

Just at the highest level .

What is going on when you have multiple wires ?

It's pretty simple when those sets of wires coming in is providing power to this box right here .

Then the other sets of wires are going to other receptacles or lights on the same circuit , that same circuit that's connected up to the circuit breaker that you have in the opposition while you're working on this circuit .

Now , when it comes to where are all those branches going ?

Where are those other sets of wires going ?

That can be not quite as simple .

Sometimes you got to really track those down and use continuity tests to understand .

OK .

Where is this wire actually going ?

Now , I do have a video link right here which will walk you through a little bit more on the continuity check with a multi meter .

If that's something you really need to track down those different branches .

But one thing that's commonly good to know is which one of these branches is actually providing the power to this box .

And for that , this is the one case where I'll flip the circuit breaker back on , I will power one of these sets of wires making sure that the hots and neutrals are not close to each other .

Everything is clear , there's no contact .

So you don't get any shorts .

Please be careful if you do not feel safe doing this .

Don't do it .

Call on a professional .

Then I use a noncontact voltage tester .

One quick note of safety on noncontact vulture testers is to test them out and confirm that they are working prior to using them on your project .

How to do this is simply go to a receptacle , you know , is powered , whether you've used an outlet tester to confirm that or you had your phone plugged in there and it was charging and confirm that your noncontact voltage tester is picking up voltage .

So I'll turn it on and then go to the small slot side which is the hot side and confirmed it's detecting voltage .

So now we're good to use the noncontact voltage tester and we're confident that it's working correctly .

Then I'll test each one of these branches and do note sometimes you'll get a little bit of noise that does not mean that branch is hot and that will usually be a single led here that might flash on and off .

Here's where we have our hot branch here .

You can see that signal strength goes up , detecting the voltage .

So our hot set of wires is this bottom set here .

So independent of what , which of the three receptacles will go over .

We put in the grounds are handled the same and we need to create what's called a pig tail with a six inch strand of bare copper .

You can either use a standard wire net .

There are also some specialty wire nets for this or you can use what I prefer for the D I wires , which is the WA 0221 lever nets .

So let me create that pigtail quickly .

So now we have the pigtail using the lago 221 to give us a single strand going to ground .

Now , if we were going to do the first example , which is just a commercial grade receptacle , we can bring our three wires in each side .

So three wires going to hot three wires coming to silver and that is up to code and this receptacle has been certified by U L to be able to carry the load from the other branches .

You can do that .

Most professionals would prefer to do the same thing you did on the ground and make pig tails out of your hot and pigtails out of your neutral .

It gives a better overall product and it's easier to get the receptacle set back in the box and in place because you don't have so many wires , wires coming in and then pushing against the receptacle as you're trying to set it in the box .

So either way is ok , if you have a commercial grade , if you had a residential grade receptacle , here's an example , if you had 14 gauge wire , I've actually found this in a house and it led to a failure where they used speed wiring for two of the wires and then a clockwise j hook on one of the screw terminals .

This also is technically OK .

This outlet is certified for that , but I do not recommend doing that .

There's a 50 cent receptacle and I do not trust the speed wires .

And I think this increases your likelihood for failure in the future .

So I do not recommend this .

And in this case , I would use and have used a pigtail example two for a G F C I , this is where it's very important to know the line , the power coming in .

And it's denoted by line here within the G F C I .

You can see that .

So the power coming in with the line would go within this side of the receptacle and then you take off the sticker and here is your load side .

So again , you can bring these two sets of wires in the top here for your load following your strip gauge on the back of the receptacle .

And in this case if you wired correctly to the load side , this branch and this branch can be a standard receptacle and they're still gonna be protected by the G F C I .

And then the last example is actually what I'm going to wire in here .

And that is this integrated USB port Laron , I only have a single terminal so I can't take in these three and do that correctly .

So what I'm gonna do is I'm going to pigtail using the wa the hot and the neutral side .

So now I have a single set of wires , one going to ground , one going to neutral and then one going to hot .

Now it should be noted using the strip guide on the back of this receptacle .

I knew how much insulation I take off to use the back wiring .

That's where you're going straight in with the copper and you're underneath the plate which then pressure is applied to when you tighten this screw terminal here .

So not only did I need to do this because I did not have the amount of spots within the screw terminal .

This is also gonna help me fit this receptacle inside the box because I don't have as many sets of wires pushing against the housing as we try to tighten it within the box .

Hopefully , now you have a little better understanding on the scenarios you might see multiple wires coming into a box and then also what to do whether it's a standard receptacle .

You're trying to replace a G F C I or something like the receptacle with integrated USB C like the one behind me .

But if you have any additional questions or just comments , feel free to jump down below the video in the comments section and we always appreciate hearing from you .

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We have multiple videos coming up per week to help you with your repairs and improvements around the house and we'll catch you on the next one .

Take care .