Newb question on adding a receptacle.

[Swancoat]

I'm going to hang an LCD tv, and rather than just run the power cable through a hole in the drywall, I thought I'd do it right and put a receptacle up behind the TV.
 
I was thinking of using one of the powerbridge products, but given that that will still use one of my existing receptacles, and taking account of the actual effort and cost of those things, I figured I'd add a receptacle behind the TV.
 
On the plus side, there is a receptacle immediately below, so I don't need to cross studs or anything. Uninsulated wall. Running the romex should be easy (WILL be easy actually - I have pics of the walls before the drywall went up, so I know exactly what's in there ).
 
My question is more on the wiring side of it. The receptacle below is not the 'last' receptacle in the circuit, the romex comes into that receptacle, and then moves on to another. ... so what is the correct way to wire the new receptacle to that? I assume I can just use some pigtails or whatever and just tap into one of the sides of the existing receptacle (effectively wiring the new circuit in parallel - I figure this is how the receptacles supply power to the devices plugged into them anyway). Is this correct? I don't want to do anything stupid.

 

[pete_c]

I just recently (2 months ago) did one here in the house for a smaller 36" LCD TV.  I used a small insert box with power receptacle on the bottom but angled and one plate with multiple keystone jacks on it.  There was an outlet right below and between the studs.  I went into the gang box and just attached the 120 VAC wiring to the in place receptacle.  I prefer using the tabs/screws on the side of the 120VAC receptacle than twist tying new wires/nuts. Uses less space that way. I did bring a third wire up such that I have a black, white and green wire.  The green wire attaches to the ground scew in the back of the metal can on the botton.  (black- AC hot, White-Neutral and Green-ground or earth ground) I had no issues. 
 
For the media room LCD TV I ran new circuits back to the fuse panel for additional power and to separate the HV circuits from the lighting, et al.
 
Make sure you follow saftey guidelines when you are working with the 120VAC lines. 

 

[wuench]

Also make sure you do not exceed the box fill limits for the box you are tapping into...
 
http://ecmweb.com/code-basics/box-fill-calculations
 
But you can daisy chain off the existing outlet, or use pig tails, whatever you find easier and depending on what kind of terminals you have on the outlet you are tapping into.

 

[tmbrown97]

yeah with the screw terminals on the side, you can have up to 4 sets of wiring typically; one on either side of each screw - so the incoming hot plus 3 downline.  If your outlets have the push terminals (I don't think they're allowed anymore) those only have room for 2 but often the screws are still there anyway, or a new outlet is like $2 from HD.
 
Good call BTW - running the power cord through a hole in the wall is against code, albeit one of the most common violations you'll see nowadays.

 

[drvnbysound]

I've been making my own 'powerbridge' solution for quite some time now... basically buying one of these, and a standard receptacle.

 

[pete_c]

Good call BTW - running the power cord through a hole in the wall is against code, albeit one of the most common violations you'll see nowadays

.
Most of the "professionally" installed by XX big box company LCD installations are circumventing the local electrical codes running 120VAC extension cords through the walls. On the same note though the cost of installation using a certified electrician would push the installation of the "on wall" LCD mounted stuff to some way higher amount though.
 
Sad because the customer is paying for an installation that is half baked and they are basically paying for the installation of "professionally" installed holes in the drywall with the top one being a LV/HV insert hole to the bottom of the wall exit hole (fancy as it might look).  I have seen these "professionally" installed costs now at some $250 to $500 depending on how many wires are in the holes. 

 

[JimS]

If you have a newer outlet with clamp bars on the screws (rather than just wrapping the screws around the screw head) that will make this easier.  If not then pick up a new one.  Then do as Work2Play said.  It can be done with other type screws but requires wire nuts and is a lot more to cram into the box.
 
For the ground there are a lot of wires to connect together - no way around it but you can do a few things to save a few wires.  You can get green wire nuts with a hole in the top so one wire can continue to the screw (or another wire nut) which saves some wires.  If the box is plastic then just connect the wire to the outlet ground screw.  If a metal box take it to the box with a ground screw but leave a long tail that can be run from box to outlet ground screw.  I think the rule is that the outlet should be able to be removed without breaking the ground connection to the downstream outlets but that would usually be the case anyway.
 
You may need a bigger box to meet fill limits (and make it a lot easier to cram everything in!).

 

[sda]

The back wire (clamping) receptacle is a good choice, but Its a lot easier to use pigtails (just the H-N-G wires to the receptacle) than to stuff a receptacle into a box with 7 wires attached to it.
 
If you don't need the existing receptacle, just get rid of it and blank off the box.  
 
And whatever you do, don't use the backstab connectors on the receptacle.
Sure, they're fine today, and probably next year, but in the long run they can get loose and cause problems.

 

[Swancoat]

Wow, thanks for all of the awesome advice.
 
Work2Play: You answered my main question by suggesting I can use the side clamps to connect the 'incoming hot and 3 downline' (I really need to do 2 downline, but whatever - it answered my question). Thanks.
 
wuench: Thanks for the box fill link. I was completely unaware of such a concept, and have no idea how 'big' the box is in there right now. It sounds like it'd be pretty close to full. Not interested in yanking a box out and patching drywall or anything silly like that, so...  still thinking this over (More importantly - Is this just a 'volume' concept applied to electricity? i.e. Do my Insteon switches consume more 'box volume' than a standard switch? (They are absolutely a lot bigger physically.) Some of my wires are really stuffed in those boxes. Is this a big problem?
 
All in all, I had considered the power inlet, but like I said, once I'm wiring up some romex and adding new boxes anyway, adding a true receptacle seemed to be a better solution. Well... I've been looking over my lovely stud-and-wiring photographs, and realizing I may want to actually mount the TV one stud over. Except that stud also happens to be where the a wall butts up on the other side of the wall in question, which basically results in not a stud, but about two studs 6 inches apart, with romex running down one of them, and LV running down the other. Not sure of how I would even drill through there without cutting a 3 sq ft hole of drywall out. I think I am just going to do the power inlet. Easiest solution by far. Still should be up to code, etc..

 

[Neurorad]

I also recently used that Midlite 'extender' that drvbysound linked above, using a conventional outlet, with the 2 linked by Romex. Using a power bridge or adding an outlet will each require Romex.

Use a TV box from Arlington behind the TV, combined LV and line voltage. I would choose a 3 gang, minimum.

 

[Del91574]

You'd be amazed at the surgery that can be done to remove and replace a box with a larger one that requires no painting/patching...or even moving to a 2 gang box/ring combo. If you're lucky, you have "deep" boxes installed, so pigtailing, while a PITA, isn't generally frowned upon.
 
And I do agree with the halfbaked installs that are being done, mainly by the big box "geeks" that are far from compliant. Matter of time before someone gets hurt or worse and changes come to the industry,.