Since we first moved into our new home, I have begun research on Do It Yourself projects to improve our home. DIY projects if done right and with a little bit of research can add equity to your home and can give you the feeling of accomplishment of doing it yourself. If done right it can save from a little bit of money to a heap of money (depending on the project and scope).
My first major project on our new (99 yr old) house is to update some of the electrical wiring and add a few circuits to the existing panel. Firstly let me explain that I am not a licensed electrician and when I first started undertaking this project I didn’t know much more than the basics about residential AC wiring/electricity. My first step was to do some major research on residential electricity, wiring and the NEC or National Electrical Code. With a good grasp of the basics of electricity and it’s dangers and a good understanding of how a residential home is wired. I had to learn about the NEC. The NEC essentially is the code requirements for how wiring, panels, and other electrical requirements for all aspects and areas of the home among the other covered areas (i.e. industrial, commercial). Most of the NEC code requirements are safety requirements to reduce death and injury from electrical shock as well as reduction of electrical fire risks from wiring. The NEC is updated on a somewhat regular basis and is the basis for most local codes, however some local areas have much stricter codes than the NEC requires and makes it extremely important to check local codes in addition to the most current NEC regulations.
After letting all that information settle a little bit I was ready to get started. My first part of this project which I have completed, was to place two pull chain lights in my unfinished laundry room area on a switch, and remove several older sections of wiring that were no longer in service but still hot and wired in. At this point I wasn’t ready to put a brand new circuit in and run the wiring. There was a junction box with two existing circuits directly in the middle of the room that made it easy to tie into one of these.
My next step was to start tracing lines out on the circuit I was going to tie into to make sure that I wasn’t going to fry anything and not overload the circuit. The two lights in question were already on the circuit already so overloading the circuit would not be an issue. I just had to make sure that I knew what wires were what circuit. This turned out to be a chore as throughout the years several new junctions were added above the ceiling panels in my basement and there is a ton of wiring running through the basement, old knob and tube, 40’s synthetic shielded cable and modern Non-metallic all throughout.
Before I kill the power and start ripping wiring out, it’s wise to check and make sure I have all the tools, parts and supplies I’ll need. Here is what I used:
- Voltage Tester
- Pliers (Lineman’s, Needle-nose)
- Screwdrivers (#2 phillips, flathead)
- Extension cord
- Trouble Light w/ clamp, and flashlight
- Corded drill and bits
- Tape Measure
- wire stripper
- cable sheath splitter
Parts & Supplies
- Electrical tape
- Wire Nuts (sized for wiring used, 12awg) about $2-$3 per bag of 25ct depending on the size.
- 25′ of 12-2 cable (12-2 stands for 12awg(gauge), 2 conductor +ground) approx $12 for 25′ roll, I also bought a 100′ roll of 12-2 for the rest of this project and future projects @ $30 for 100′.
- 2 metal 4″ square extra deep junction boxes and covers (metal ones are a bit more expensive but a little more durable @ approx $3 ea with the covers)
- 1/2″ insulated cable staples (about $2.50 for box of 50, and $10 for 500)
- 1 1/4″ #10 wood screws (for mounting J-Boxes) box of 50 for just over $2.
- Surface mount extra deep gang/switch box ($5)
- Surface mount cable tray 48″ ($8)
Once the correct lines were traced it was time to kill the power to the circuit and test it for voltage. This is where an audible voltage sensor for $9 at Menards payed for itself on the first day.
Of course one should always test on a known hot circuit before testing a circuit after killing power. Once the power was killed for that circuit and all lines proven dead it was time to start ripping out the old wiring. I had planned on using the existing holes in the beams that the existing wiring ran through so I had to remove most of the old wiring first. Had I chosen to use another method or run new wires I would have run as much wiring as possible before killing power and thus reducing the amount of inconvenience time to the family. Since we are living in the house the least amount of down time for the circuit the better.
Once the old wiring was removed it was time to install the two new junction boxes and tie J-Box 1 into the existing circuit and run the continuing wires that went on to the rest of the circuit.
In this J-Box are two parts of the circuit; 1) Always hot portion that extends to J-Box 2 and the rest of the tied in circuit, 2) A switched sub-circuit to run the two lights.
On the switched portion of the circuit, the hot cable runs down the wall through a cable tray to the gang box where the switch is and from the switch back up to J-box 1 where it splits off to the two lights.
From J-Box 1 an always hot cable runs to the new J-Box 2 and on to the old wiring back upstairs. Another switched cable runs to Light 2. When I first started planning this part of the project this area of the basement wiring had me concerned. The person who wired this circuit before had placed 1 hot cable into the J-Box with the light and 7 other hot cables running out. Three of these hot cables went to absolutely nothing. In fact one cable loosely ran down the stud next to the dryer and was taped off on the hot with a small piece of electrical tape. This to me was a major safety and fire hazard to say the least. This could easily have been fixed by simply killing power and removing the unused cables from the box. I decided to add the second J-Box to this area to reduce the amount of wiring going into the small light J-Box which was originally crammed full of splices. The new J-Box is big enough to accommodate the existing wiring and then some with room to spare if need be.
Once all the cables were ran each part of the circuit was stripped and securely spliced together with wire nuts and tucked away neatly in each J-Box. I waited on placing the covers and securing everything until everything was tested and proved to be in proper working order.
After everything was tested the power was killed again and all J-Boxes were closed up and everything was double checked. I turned the power back on and we now have a set of switched lights in the basement instead of pull chains, and some old fire hazard wiring was removed.
In the near future I will be replacing the simple lights in the basement and placing two fluorescent light fixtures, as well as adding a new circuit to the breaker panel.
- Wikipedia: NEC
- Free restricted online access to NEC 2008 code
- Electrical wiring FAQs
- DIY Electrical Articles
- Self Help Forums