I need to add another outlet in my basement- The closest source of electricity is another single outlet on the wall. This one single outlet has power coming into it (I think from another junction box), and then feeds another outlet to the end of the circuit. Can I tap off of this outlet to install another one?? How would I wire it?

 

Your question indicates that you have little or no experience in home wiring. So please read a book on home wiring before starting. There are a number of skills and techniques you must learn to do a good job. Electrical work is more than just connecting wires together.

The project you propose is simple. Just run a new 12/2 NM-B cable (or 14/2 depending on breaker size) into this receptacle box. You'll need to buy some wire nuts, because receptacles only have two screws and you will have three wires of each color. Use a wire nut and a short piece of wire of the same color (called a "pigtail") to connect all three black wires and the black pigtail to each other. Then you can connect the other end of the pigtail to one of the brass screws. Do the same with the white wires to the silver screw, and the bare wires to the green screw.

 

There are several good books at Lowes, Home Depot, and the major bookseller chains. Most have excellent photos and accompanying instructions of just exactly what John Nelson described, and they range from $11.95 to around $20 bucks. The less expensive one has fewer types of electrical work, but will certainly have this project detailed. I understand his instructions because I've done electrical work for over 20 years and can picture it in my head. Also, your local public library has an assortment of home wiring books as well.

If your outlet boxes are metal, they have a "knock out" in the side. With power off, poke a screw driver in it and bend until it snaps off. To safely pass the NM-B cable through that metal hole, and hold the cable firmly to the box, you'll need a "romex connector. Your local home center will help you out with the right parts if you describe what you're doing.

Hope that helps.

Juice

 

Ok thanks guys- I'll purchase a book tonight at Lowes since I will have to do more wiring.. Just one more question since it may not be in the wiring book- If I connect a new cable to that existing outlet box (which is mounted on cement wall).... do I have to run the cable through conduit, or can I just run a piece of wood to staple to?
Thanks again

 

Code requires "physical protection". This is subject to interpretation. Most people would use conduit (or armored cable), but the wood would probably work too. I think stapling it to the side of the board would offer much better protection than stapling it to the face. If the job will be inspected, I might ask the inspector ahead of time.

 

The NEC does not permit NM cable to be stapled to the underside of your joists unless you first install a "runner board". This can be a simple 1 x 2 or 1 x 4. Then you would staple the NM cable to the runner. That is acceptable. I prefer to run my NM on the side of the joist where possible. If you must run perpendicular to joists, you may drill a hole in it to pass the cable through, but drill in the center of the joist, because structurally that is the area that carries the least load.

Of course conduit is always permitted. But you must run individual wires in it. Do not put multi-conductor cable in conduit because the conduit size requirements are different for cable than for individual wires and you also must de-rate the ampacity of the wire in the cable because cable traps heat and when you run it in conduit the conduit further traps it. Either cable or individual wire in conduit dissapate heat at an acceptable rate. But a wrapper in a wrapper dissapates heat at an unacceptable rate.

Juice

 

Juice, I could be wrong, but I don't think there are any joists in this problem.

 

After re-reading the post I found that I had misread John's earlier advice, about stapling the NM cable to the face of the wood. I realize now he was talking about attaching a runner board to the concrete wall.

Personally, if I were to run wiring across a concrete wall I would install EMT (conduit) across it with conduit straps. Of course that would mean installing individual #12 AWG type THHN/THWN conductors - one black, one white, and one green. I would recommend solid over stranded, like you would find in NM cable. You can buy it by the foot at your major home centers. It's cheap. My advice is to measure twice, allow for a minimum or 4" extra sticking out of the box at each end (code requirement), --- and then I would add an additional three feet! Best to have a couple feet of waste than to be even one inch short. This avoids the kick-yourself factor later.

When purchasing conduit, make sure to buy two threaded adapters for connecting the conduit to your outlet boxes at each end, and a sufficient quantity of couplings to join conduits together if your run is over 10-feet (standard conduit length). Also any elbows for your bends if you have any, unless you have a conduit bender. (Don't try to bend EMT without one!) And when cutting EMT, if you have a tubing cutter that is best. If you don't a hack saw is fine. But either way, you have to ream or file the inside of the cut end smooth or it may cut or damage the insulation on your conductors causing a short or a shock hazard.

Juice