Basement Wiring - codes and diagrams
To most people, basement wiring is both mysterious and 
dangerous. Follow and comply with the NEC (National Electric Code) and you and the people involved will be safe.Note: Weather you are working on, electrical switches or any electrical outlet, it is just as easy to be safe then not. If you are not sure, ask an electrician or your local inspector. They do not mind to help you with any questions you might have.
Buy an electrical code book and follow the codes. Finally, always remember. Electrical wiring is like most other projects when it comes to basement renovations. If you do not follow the safety procedures, somebody can get hurt or even killed.
Please do not attempt to take any short cuts. This is for your own safety.
For your information:
The power that supplies electricity to your house comes via overhead or underground wires to the meter that keeps track of your household’s consumption.
From the meter, it continues to a service panel with a series of circuits which supplies current throughout the house. This panel consists of a number of circuit breakers or, (fuses if the house is an older home).
Both house and basement wiring starts from this fuse/breaker panel which supply the power to the electrical outlets. "Treat this panel with respect".
These breakers or fuses are safety devices used to disconnect the power to the whole house or an individual circuit when there is an over load or a short.
Three rules
If you play golf then you must have heard of the three rules. Keep your eyes on the ball. Keep your eyes on the ball. Keep your eyes on the ball. In buying real estate, the three rules are. Location. Location. Location. When you are working with basement wiring, the three rules are Circuit breaker off, Circuit breaker off, circuit breaker off.
A house carries two different grounds. A system ground and equipment ground.The system ground is the grounding of current-carrying wires. Equipment grounding connects to metal frames of electric motor frames, appliances, etc.
One other thing you should know about basement wiring or all electrical wiring for that matter is that current travels in a continuous loop until it is interrupted by a devise, example, light switches. It starts at one point, traveling to the appliances, light switches, plug-ins, etc by means of electrical wire. and then back to where it started from at the speed of light. (that speed never changes).
In North America. Black wire is hot or live, white wire is neutral, bare or green wire is ground. (If you live in a different country. Please check your local electrical code).
The white neutral wire is connected to the bus bar in the breaker panel to complete the circuit by returning the current to its source and by doing so, it also grounds the system.
The black wire curries the current to the fixtures, light switches, appliances etc. and is connected to the circuit breaker located in the service panel.
The red wire is used when connecting a three way electrical switches or to serve as a separate circuit and is connected to a separate circuit breaker.
The bare grounding wire is either connected to a metal rod driven into the earth outside your house and to the bus bar inside the service panel or connected to your in coming water supply line and the bus bar and from there to the equipment- light switches/fixtures, and electrical outlets in your house.
Other basement wiring notes to consider.
-if you must bundle cables together make sure that the cables are not touching each other for more then 24inches.
- don’t run more then three 2-wire cables or two 3-wire cables through one hole or you will have to derate the cables.
- run supply cables to heavy loads, separate.
- use heavy gage steel plates to protect the cables from screws and nails.
- drill the holes in the studs so that they are at least 1-1/4” from the face of the stud and in the center of the floor joists.
- all electrical wiring boxes must be surrounded with moisture resistant barrier if they are located in a wall or ceiling where vapor barrier is present.
- if you are installing recessed lighting in insulated areas, you must use fixtures that are specifically certified and marked for blanketing with building insulation.
- standard lighting can be installed if there is no building insulation between the basement ceiling and the floor above the basement.
Outlets Per Circuit
Do not connect more then 12 electrical outlets on one circuit. This may consist of 12 light outlets or 12 plug-in outlets.(check your local electrical wiring code) The 12 outlet rule does not refer to appliances or “Kitchen Counter Plug-in Outlets”.
The best way is to have a combination of lights and plug-ins. As long as their total number does not exceed 12 electrical outlets.
Mix the electrical outlets between living areas this way there is a smaller chance of a whole blackout in case a circuit failure.
Electrical plug-ins should be placed at 12 inches above the floor.
Electrical switches should be at 4 feet center from the floor.
Place powered switches at 39-1/4 inches (1m) from showers, bathtubs electric heating-thermostats etc.- (Check your local electrical wiring code).
Do not staple 2-wire cables on edge, always keep them flat.
Use the right size staples. Ask your local hardware store for the right size.
Do not overdrive the staples or you can squish the cables. Drive the staples just enough to make contact with the cables.
When twisting two wires together, use a pair of pliers.
If you must connect to an existing circuit make sure to turn the circuit breaker off before performing any electrical wiring work on that circuit.
Installing plug-ins and light boxes.
Build a jig from a piece of 2x4 by 10 inches long and a piece of 1/2 inch plywood (3 inches wide by 10 inches long.Nail or screw the piece of 1/2inch plywood flash on the end of the 2x 4by 10 inches piece.
The 2x4 by 10 inches sits on the bottom plate of the wall and the plywood fits against the front of the 2x4 (facing you). The bottom of the outlet box will be even with the top of the plywood and the edge even with the edge of the plywood. The ½’’ drywall will end up flash with face of the plywood. The bottom of outlet box will be located 12 inches off the floor and ½ inch out from the 2x4.
- Using the jig as a measurement, nail the boxes to the studs
- Drill 1/2inch holes through the middle of the studs.
- Run the electric wire from the first box to the next until you finish the whole circuit and leave ten inches of black, white and ground wires and roll them while pushing them inside the box.
- Mark or number the wire that runs from the last box to the breaker box.
- Repeat the same steps to all the circuits. Don’t connect to the breakers yet.
- staple the cables every 3 feet and one foot from the boxes,
Leave half a loop of extra wire form the last staple to the box.
Once the rough-in pluming and basement wiring are completed. You can go to Basement Insulation and then go to How to hang drywall to continue with the basement renovations.
Connections of plug and light switch outlets.
Before running the basement wiring, lets take a look at the connections of light switches and plug outlets. Starting with the plug outlet.
- connect the black or hot wire to the gold/brass terminal of the receptacle and the white or neutral wire to the silver terminal.
- the ground wire shall be connected to the metal box and then 
to the green/ground screw on the receptacle.
- wrap the bare end of the wires clockwise. The same goes for the ground wires.
- neutral wires require a pigtail when connecting two or more plug receptacles to each other so that if a receptacle is removed, the power to other loads will not be interrupted.
- Cup the wire ends with wire cups. The other end connects the same, white to neutral and black to breaker. The ground connects to the bus bar.
Single pole switch.
When install a lighting circuit with a lamp. White wire connects to silver screw on the switch and black wire to the bras/gold screw on the switch. Connect the white wire from the switch to the black wire coming from the source. Connect the black wire to the brass terminal of the switch and the white wire from the source the silver screw on the light holder. The ground wire
connects to the screw on the metal box. You can either have the power entering the light outlet or the power can enter the switch outlet box. Always have the neutral wire from the source connected to the fixture or it could be fatal and we don’t want that. Right?
Study the sketches and diagrams. Basically a switch serves as an interrupter to interrupt the load from completing the circuit. 
- The white wire in a switch is hot.
Three way switches.
A three way switch is one job that confuses a lot of people. I look at a three way switch the same way as railroad track. When the train is required to change direction. The switch operator switches the tracks by using a long handle or a switch handle.
In electrical wiring terms you are switching the current flows from one direction or another . From either direction, the current flows to the lamp and then back to the source panel . (The breaker panel).
Wiring a three way switch.
The wire colors I will be discussing here, are Red, White, black and bare ground.
Let us assume that the switch boxes are in place and ready for the wiring.
Feed the 3-wire cable from one switch box (A) to the other 
switch box(B). Remove a minimum of 10 inches of insulating jacket and feed the three wires plus the ground in the metal box.
Tighten the clamp in the metal box to secure the cable and connect the ground/bare wire to the ground screw of the metal box.
With the switch facing outwards. Connect the black wire From box “A” to the top terminal of switch “A”(the screw that is by itself).
Connect the white wire from box “A” to the bottom left terminal of switch “A”(switch facing out).
Connect the red wire to the bottom right terminal of switch “A”.
Connect the wires to switch “B” the same way as switch “A” except that this time, leave the black wire disconnected.
Now lets connect to the light/light bulb.
Run a 2-wire cable from Switch “B” to the metal light box . Connect the white wire to the top screw of switch ”B” so that now there are two white wires connected to switch “B”, the ground to the metal box. Twist the bare ends of the black wires and cap them with a wire cap.
Run a 2 wire from the light metal box to the breaker box. Leave enough wire to reach the circuit breaker. Allow extra wire to reach from the wire access hole to the breaker plus some more to be able to tack the wires neatly with the other wires.
Now you can go back to the light metal box, splice (twist) the black wires together with a pair of pliers and cap them with a wire cap. Connect the white wire from switch “B” to the black wire running from the breaker box the, white wire to the light bulb and the ground wires together with a pig tail to the metal box .
Feed the 2 wire cable through the breaker box-knock out. To energize the circuit, connect the white and bare wires to the bus bar and the black to the breaker. Make sure that the main breaker is off and then you can install the circuit breaker. Turn both main and circuit breakers back on and “Then there was light.
Three way switches are probably one of the most complicated jobs that you will encounter during your electrical wiring
