Adding 3 Gang Outlets + 1 for TV

Hi there.

I just joined today because I am starting my first project in my new home.

In my living room I have two outlets, too far away for me to use with my entertainment center.

I do not want to have cables running outside my wall (extension/strips).

My project is to add a 3 duplex receptacles, 12" off the floor.

I will also like to run romex in the wall up to my mounted TV (6' up).

I've done some research and seems pretty basic to add a few outlets. My question is pertaining to the amount of connections I am adding.

I attached two images.

Would either of these plans work? Do I need anything special besides the back boxes (plastic), romex, receptacles and face plates?

 

What is the intended purpose of the "out" block on the right side of the diagram?

 

It leads to another outlet.

There are two outlets. IN (left) and Out (right). I want to cut that romex connecting the two outlets and add the 3 duplexes.

EDIT:
I labeled IN/Out because that is how I've seen other diagrams. I take it as the IN side leads to the power source (panel) and OUT would lead to the next outlet.

I could be using these incorrectly, as I have no experience with electrical work (besides thermostats).

It seems fairly easy to add 1 outlet... but I don't know about 3, and then another splice to another outlet... then continuing down the line to the next preexisting outlet.

 

Your diagram is correct, however you may not have enough cable to ensure that you have at least 6" of free conductor from each cable.

 

Thanks, but I don't follow.

Which diagram would work best?

I assumed I could get some Romex, cut it, strip it and then attach them.

 

Welcome to the forums!

Either will work if you have enough cable to get the slack you need in the new boxes, as pcboss said. On way to do that might be to offset the 3-gang box from the box for the TV and run the power in to one of them and out of the other.

Splicing the feeds and pigtails together is generally preferable to using the devices to also make the circuit connections.

Metal old-work boxes are almost always easier to work with than plastic ones. In addition, they can be bonded to ground.

Romex® is the brand of the non-metallic building wire (cable type NM-B) made and sold by Southwire, and is their registered trademark. That said, Type NM-B cabling is not approved for use in some jurisdictions. The five boroughs of New York are among those jurisdictions. Where in New York (state) do you live? Do you see Type NM-B already installed in your property?

In terms of materials, all I can think of that you haven't listed are some ground screws, some wire nuts and some cable clamps.

 

Thanks I guess I'm just a little confused .

On the diagram:
Left side is in, feeding the new outlets. On the right is the out, going to another predxisting outlet.

For the outlet on top, I will run more nm-b cable to it. Ther will not be another out on that tv outlet.

Why wouldn't there be enough cable?

 

Are you planning to run new cable to or from the 3-gang box, or are you planning to cut an existing cable and set the box in?

 

Take a piece of cable 10' long. Now cut it in the middle giving you two 5' pieces. Try to install a box at the cut you need at least 6" more cable from both sides to allow the splice to be made in the box.

 

I'd prefer to just cut that one cable and put the 3 gang in.

 

I see your point. I guess I need to re-run the cable from in to new outlets.

 

I will have my walls open (to studs) when doing this. So I can easily run new NM-B cable.

From what I gather, you cannot ground in a plastic box... so I do need to use a 3-gang metal for the outlets behind the entertainment center and then another 1-gang for behind the TV.

Is there a specific wirenut size I need to use for the all of this?

I am going to use something like this:
Shop STEEL CITY 44-1/4-cu in 3-Gang Old Work Metal Electrical Box at Lowes.com

Does this box allow the use of grounding screws?

 

There is no need to ground a plastic box. It s non-conductive.

I would use something like this.

Arlington | Home Theater • Audio/Video

A typical red wire nut is good for 5 #12's. More than that and you will need a large blue or gray.

 

Thanks for that.

So I can run NM-B cable into this type of plastic box? I don't need to ground the outlets?

 

The receptacles do need to be grounded. A plastic box does not.

NM cable can be used with that box. You do need a proper connector.

 

So then why use a plastic box for outlets?

I'm not sure what components to use. The diagram should be good - what connects to what...

I will run new NM from existing outlet to the new outlet. Then another NM cable up to the TV.

That much is good.

So for this type of setup, I'd need to ground the duplex receptacles.

Does this require the use of a metal box to attach the ground wire to?

How would you ground all of those receptacles in the 3-gang box - whether it is metal or plastic?

 

Your diagrams show the proper receptacle grounding. Plastic is non-conductive so there is no point in connecting the ground to it.

Plastic boxes are typically cheaper and faster to work with and you save time be not needing to ground them.

 

Gotcha. So I'll use the plastic boxes then.

The grounds to the receptacles are all good.

For the ground wire specifically, can I use the same red wirenuts as I can w/ hot and neutral wires?

I'll probably go with the 2nd diagram (using the pigtails between receptacles).

This would require 3 red wire nuts. One for hot, one for neutral and one for ground.

The ground wire looks thicker/harder.

 

You will need to see if the red wire nut is listed for the number of conductors you are trying to splice.

The ground wire is the same size in a 14-x or a 12-x cable.

 

Black = 4 connections
White = 4 connections
Ground = 6 connections. I'm guessing I need a larger nut for the ground than the black/white.

 

Yes, a large blue or gray should work for the grounds.

 

Thanks. I appreciate all your help.

I'll go w/ diagram two and use the following behind the TV.
Arlington TVBU505BL-1 Recessed TV Outlet Box with Paintable Trim Plate, Black, 2-Gang - Amazon.com

I'll use plastic boxes and ground each receptacle using the ground wire in the NM-B cable.

I'll use the red nuts for the hot/neutral wires.
I'll use the large gray nut for the grounds.

Then test each receptacle using a meter prior to plugging any devices in.

Once everything looks good, I'll run my HDMI/Speakers/Coax/Subwoofer cables in the walls to new face plates behind the entertainment center.

 

You can use plastic boxes if you want to. I always use metal boxes because they are bonded to ground. It's one more measure of safety.

I also connect each device to ground.

I test wiring with a meter. I test receptacles with a plug-in receptacle tester.

 

Thanks. I'll take the advise. I'll go w/ metal boxes.

So that changes things just a bit. How would you ground the box?

 

Whenever possible I leave the ground wire in the panel feed extra long - say 12" or so. That wire gets wrapped clockwise, and crimped tight, around a green 10-32 ground screw threaded into one of the available holes in the back of the box. Then the tail of that wire is spliced to the other ground wires, including a pigtail for each device.

You can also install a ground tail, make one yourself, or use a wire nut with a pigtail built in.

 

Confused a bit now.

If the ground is coming from the NM-B... and you attach that ground to the box/screw... the other end isn't available to use.

 

I didn't realize more than one person had replied to my questions...

Thanks. I don't know what to do now... metal or plastic box...

For metal boxes (like the Arlington I linked) - I guess I have to ground the box itself. How can I do that and also ground the receptacles?

 

It is if the wire is 12" long to begin with and you only need 4" to get to the screw and loop it around.

 

I'm specifically using Romex branded cable. So it has hot/neutral/ground all in the single cable.

For the images I posted. If using plastic boxes, would the diagram be correct?

 

Yes. Yes, that is the same for all cable brands. Not sure I understand your question.

 

I'm just a bit confused on grounding the box.

If using plastic, then I don't need to ground the box. So the 2nd diagram will work.

No other question. I misunderstood the previous poster.