Pages

Nov 12, 2013

DIY a Built-in Extension Outlet

I've received a couple of emails asking how we converted a wall outlet into an extension outlet for our TV room sofa table. This outlet, built into the face of the table, allows us to utilize the electrical outlet that is behind the couch - without having to move the couch out of the way. I managed to corral Tom long enough to have him show me what he did.

I shouldn't have to mention this, but if you are not comfortable/knowledgeable about working around electricity and electrical outlets, do not attempt to install this yourself.

Update: We recently upgraded to an outlet with built-in USB ports, and I asked Tom to switch to a grounded wire at that time. Instructions are the same - refer to additional step for attaching third (ground) wire below.

DIY built-in extension outlet

For this reconstruction we used spare parts we had laying around, but I'll also intersperse the photos and instructions with what we did the first time. However, the steps are exactly the same.

Parts you will need:
DIY built-in extension outlet


Tools you will need:
DIY built-in extension outlet

If you're installing this outlet onto the face of a board - like a table - the first thing you'll want to do is cut a hole in the table the same size as the electrical box. Tom used a rotary zip saw, but you could also use a jigsaw.

DIY built-in extension outlet

When Tom installed the original outlets he used an airtight electrical box like this that had a frame around it.

DIY built-in extension outlet

He was able to screw the frame directly to the underside of the table. An airtight box wasn't necessary but it was all the store had in stock. If your electrical box doesn't have a frame, you can install a piece of scrap wood to the underside of your surface, and attach the box to it. That's what I'm going to show you here.

Fit the electrical box into place and hold the scrap wood against it, along the side of the box with the bracket.

DIY built-in extension outlet

Drill pilot holes through your surface and into the scrap board. Make sure they are very, very close to the hole so that the face plate will cover them. 

DIY built-in extension outlet

Attach the screws so that your scrap board is held in place.

DIY built-in extension outlet

Flip your table upside down and set it on a stable surface like a workbench, or even on the floor. It'll be much easier to attach the electrical box without having to crawl under the table. Using the holes in the electrical box bracket as a guide, attach screws on each side so that the box is securely fastened to your scrap board. 

DIY built-in extension outlet

As I mentioned, if you are using an airtight box with a frame, you'll just use short screws and attach the box directly to the underside of your surface. You don't want the screws poking through the topside, so measure carefully. I prefer the look of the airtight box but you have to work with what you can find. And from the top it won't look any different.

Once your box is mounted to the board, you can work on attaching the wiring.  Take your extension cord and cut off the outlet connector (the socket end). Our outlet is only used to plug in lamps, phones, computers, etc., so we bought a light-duty 2-pronged cord, but if you are using your outlet for more heavy-duty loads or in wet areas, you'll want a 3-pronged grounded cord.

DIY built-in extension outlet

Take the cut end of the cord and split the two wire bundles apart. Using your sidecutters, a knife or wire strippers, carefully cut through the plastic sheath without cutting the wire inside and pull it off. You'll want to have about an inch of exposed wire. Do this on both wires. Twist each bundle of exposed wire tightly so that it isn't fanned out.

DIY built-in extension outlet
DIY built-in extension outlet
DIY built-in extension outlet
DIY built-in extension outlet

If you are using a grounded wire, there will only be one sheath. When you strip it off you'll find three more wire sheaths, white, black, and green. The green one is the grounded wire. You'll need to strip off an inch of each coloured sheath to expose the copper wire. It should look something like this:

DIY built-in extension outlet

Feed the two wires through one of the openings in the underside of the electrical box. The tabs are made of plastic, so you should be able to push them in slightly, enough to get the wire through. Pull the wire up through the front of the box so that you have enough to work with.

DIY built-in extension outlet

DIY built-in extension outlet

Your electrical outlet will come with 4 brass screws, 2 on each side. Tighten one on each side just to get it out of your way.

DIY built-in extension outlet

Take one of your wires and twist the exposed end around one of the (untightened) screws on the outlet. Make sure that you twist the wire in the same direction as you will be tightening the screw (usually clockwise). Tighten the screw down. Repeat this on the other side of the outlet.

DIY built-in extension outlet

 If you are using an extension cord with a third ground wire, attach that wire (which you previously stripped as above) to either the green screw in the bottom of the electrical box, or to the green screw that's right on the electrical outlet. Either place works, as once the electrical outlet is attached to the box the circuit will be complete.

DIY built-in extension outlet

Once your wires are attached, screw the outlet into the box through the holes at either end (the correct screws should be provided with your outlet). Attach your faceplate and you're done.

DIY built-in extension outlet

DIY built-in extension outlet

When we put the outlets in the sofa table we used a larger rectangular outlet versus the common outlet with rounded corners. These outlets require a slightly larger faceplate - which is beneficial to you if you're using the scrap board mounting method and need to cover up your screw holes.

DIY built-in extension outlet

Once Tom showed me how to install this outlet, I couldn't believe how easy it was. I'm terrified of electricity, but I think even I could do this without being afraid of zapping myself.

I'm thinking of attaching one to the side of my craft table so that I don't have to crawl under the table all the time to plug things in - the sewing machine, the Silhouette cutting machine, laptop, etc. I'm switching them out and moving them around all the time - this will make it a lot easier. Not to mention, I can move the table around and the electrical outlet will move with me.

DIY built-in extension outlet

DIY built-in extension outlet

DIY built-in extension outlet

DIY built-in extension outlet

24 comments:

  1. This is a FANTASTIC idea. I have some built ins that I keep running the cords up and behind.. I should install this and make it permanent! Great tutorial! LOVE IT!!

    ReplyDelete
  2. Oh my gosh! So, so smart! I love this idea. It is going on my list for our Alaskan cabin or my dream Belize Beach House. Yeah, that second one is years in the future. Thank you for linking up to Tips and Tricks.

    ReplyDelete
  3. This is an awesome tutorial! What a great idea. I need to do this in my craft room. Pinning!

    ReplyDelete
  4. Wonderful tutorial! You made the process so much simpler!

    ReplyDelete
  5. Glad you liked it. I want to install more too!

    ReplyDelete
  6. My dream house is in Hawaii (but I've never been to Belize.) I could come build them for you! ;-)

    ReplyDelete
  7. Yes, if it's in the winter. Summers in Alaska are something to behold. Absolutely breathtakingly beautiful.

    ReplyDelete
  8. Ha! You know I meant Belize and not Alaska, right? :-)

    ReplyDelete
  9. That's it exactly. Plus they're easier to unplug!

    ReplyDelete
  10. I think your project was awesome and that's why I featured it at Craftionary.. :) Thanks for linking up at The weekly creative.. Come by and see other fun projects that got featured along with you.

    Have a great weekend! :)

    ReplyDelete
  11. Very nice. They have outlets now that have not only the traditional plugs but two USB ports for charging devices......might be a better option so that people can charge things as well.

    ReplyDelete
  12. That would be awesome - I might have to switch them up!

    ReplyDelete
  13. Nice idea but it's also incredibly dangerous as shown. You bypassed the grounding circuit by using two-wire lamp cord. You also use a wire gauge that is too small for the circuit ( you should use a minimum of 14 gauge with a ground wire) Also, since you've installed the outlet in an area that's flat, you've created an opportunity for liquids (or kids) to get into the outlet and create an electrocution hazard. You should change the wall outlet to a GFCI or Arc Fault receptacle, use only a 14 gauge grounded cable (or better) for the extension and put a child-resistant cover over the outlet.

    ReplyDelete
  14. Approximately how much did the supplies cost you? How long did it take? Also if a fire inspector or a house inspector saw this -- would this pass for code and safety?

    This looks like a great project and I so want to do this but I am a safety girl and wanna make sure this is safe and cost effective.

    Thanks!!!

    Sincerely,
    Rachel
    raechick7@gmail.com

    ReplyDelete
  15. Hi Rachel,

    The supplies are pretty inexpensive - maybe $20? It would depend on what kind of load you were planning on putting on the outlet - you might require parts that can handle that higher load. My husband built these ones and it probably didn't take him more than 15 minutes. He demonstrated one for me after, and I think, being a complete novice, I could do it myself in under an hour. I think stripping the wire would be the hardest part.

    We only use ours to plug in table lamps, sometimes phones. We'd never use it to run powertools or anything like that. So it's basically a fancy extension cord. If you're using something that needs to be grounded you would want to upgrade to a 3-prong extension cord like the one I show in the instructions, and make sure the ground wire is connected.

    Likewise, if you're worried about shorts or shocks - for example from liquid getting into the outlet - you might want to look at a GFCI outlet like the ones used in bathrooms.

    Since this is not a permanent fixture in our house, a house inspector wouldn't even be interested in it. When we move it'll come with us. Like most things, it all comes down to common sense - don't overload a circuit, and don't be reckless when it comes to liquids and electricity.

    I think you'll do great! Good luck!

    ReplyDelete
  16. Article as describe is completely illegal electrical work, if that burns a house down or kills someone you could easily be looking at a law suit.

    Nice idea but you might wanted to revise the article and consult a skilled electrician for how to do it. Clearly the person that did this should not be giving advise.

    ReplyDelete