# Do It Yourself: Electrical Wiring

Written by stephen benham
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Home electrical wiring must conform to the National Electrical Code (NEC), but it does not preclude you from doing some simple do-it-yourself electrical wiring. Electricity, however, can be dangerous, so it's important to have a basic understanding of electrical wiring and to be a reasonably competent do-it-yourself individual. Selecting the correct type of wire for the job you intend to do is important; a wire that's too thin or doesn't have the correct protective coating can cause an electrical fire.

Skill level:
Challenging

### Things you need

• Calculator
• Tri-core non-metallic wire
• Wire strippers
• Screwdriver

## Instructions

1. 1

Check the ampere rating on the appliance or electrical device you need to wire. The rating is on the label. If the appliance label lists only the wattage, then simply divide the wattage by the voltage in your home using a calculator to work out the amperes. For example, if the wattage on the appliance says 1,000 watts, then divide 1,000 by 110 to get 9 amperes. Home voltage is usually between 110 and 120 volts, but you can check the voltage by looking at your electricity panel or electricity meter.

2. 2

Measure the distance between the plug socket and the appliance using a tape measure. Multiply the distance by 2. For example, if the distance is 5 feet, then multiply it by 2 to get 10 feet. You need to do this so you get the right wire size. A complete circuit goes from the power source to the appliance and then back to the power source.

3. 3

Calculate the wire gauge you need by visiting the following website: engineeringtoolbox.com/amps-wire-gauge-d_730.html. Look at the table and find the column that corresponds to the amperes you noted and the line that corresponds to the distance you measured. The white box where the column and the line meet is the wire gauge you need to use.

4. 4

Get the wire you need from any electrical store, but ensure it has a non-metallic (NM) coating and is tri-core wire. Tri-core wire has three internal wires, one positive, one neutral and one ground. The colours of the neutral and ground wire are mandated under the NEC and must be white or grey for neutral, and green, or green and yellow striped, for ground. The positive wire can be red, black or orange.

5. 5

Remove 2 inches of the NM coating off each end of the wire using wire strippers. You now have three coloured wires at each end. Use the wire strippers to remove 1/4 inch of coloured plastic of the internal wires so the metal core is exposed.

6. 6

Use a screwdriver and remove the screw holding the plug cover in place. Lift off the plug cover so you can access the terminal connectors inside the plug. Loosen the three screws on the terminal connectors just enough so you can slide the wires under them.

7. 7

Insert the end of the green wire under the top, centrally placed terminal screw. Tighten the screw. Insert the white or grey wire under the terminal screw on the lower left side of the plug as it's facing you and then tighten the screw. Insert the red, black or orange wire under the terminal screw on the lower right side of the plug and then tighten the screw. Replace the plug cover and tighten the screw on the cover so it's held in place.

8. 8

Open the electrical access panel on the device you're wiring. It may unclip, so use your fingers to unclip it, or it may be held in place by a screw, so use a screwdriver to remove the screw.

9. 9

Look for the labels on the three terminal connectors. One is marked "+" for positive, another is marked "-" for neutral, and the third is marked "Gnd" or "T" for ground. Loosen the three terminal screws.

10. 10

Get the opposite end of the wire you've just connected to the plug nearby the appliance. Slide the green wire under the terminal screw labelled "Gnd" or "T" and then tighten the screw. Slide the white or grey wire under the terminal screw labelled "-" and tighten the screw. Insert the red, black or orange wire under the terminal screw labelled "+" and tighten the screw. Replace the cover by flipping it shut so it clips, or replacing the screw in the screw hole and tightening the screw.

11. 11

Insert the plug into the wall socket. Turn on the power. Switch on the appliance to check if it operates.

#### Tips and warnings

• Internal electrical wiring, such as wiring that's inside the walls of your home and feeds the wall sockets and light switches, is best left to a professional electrician.

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