Introduction
Electrical work can seem daunting to the average homeowner. The tangled mess of wires, risk of electrocution, and potential for burning your house down is enough to make anyone hesitate before grabbing a wire nut. However, with the right knowledge and safety precautions, even a total novice can successfully wire basic electrical projects in their home.
In this guide, I'll share the essential electrical safety tips and wiring techniques electricians learn in trade school - but don't necessarily want DIYers to know. We'll cover everything from buying the right tools and materials, to wiring switches, outlets, and light fixtures.
While complex tasks like wiring a whole house or installing a hot tub should be left to the professionals, you can absolutely wire basic projects safely if you educate yourself, work carefully, and get inspected when required. Let's get started!
Electrical Safety Tips
Before touching a single wire, the number one rule is: safety first! Many electrical accidents can be avoided simply by following basic precautions:
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Always turn off power at the breaker before working - Don't take chances working on live wires. Locate the correct circuit breaker, double check with a voltage tester that power is off, and only then proceed with wiring.
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Use GFCI outlets - Install ground-fault circuit interrupter (GFCI) outlets wherever electricity and water could meet - kitchens, bathrooms, laundry rooms, etc. GFCIs shut off power in milliseconds if electricity leaks through water, reducing shock risk.
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Check your work before turning power back on - Inspect all connections, make sure no bare wire is exposed, test with a voltage meter, and only then turn the power back on to test your work.
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Be sober - Never work on electrical projects while tired, rushed, or intoxicated. Mistakes under these conditions can be deadly.
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Consult local codes - Electrical codes exist for your safety. Always check with your local building department to ensure your DIY work will pass inspection.
Follow these common sense rules, proceed slowly and carefully, and you can wire projects safely. Now let's look at choosing the right materials.
Buying the Correct Electrical Materials
Shoddy materials can lead to faulty connections, fire hazards, and electrocution down the road. Invest in high quality electrical supplies:
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Wire - For 15 amp household circuits, use 14 gauge or thicker copper wire only. Match wire size to circuit amperage.
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Connectors - Use twist-on wire connectors (wire nuts) rated for the wire size you're using. Avoid cheaper push-in connectors.
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Boxes - Choose sturdy electrical boxes specifically designed for housing connections and mounting fixtures.
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Switches / outlets - Spend a few dollars more for durable, high quality units that are less likely to fail over time.
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Conduit - Protect wire runs with metal or PVC conduit. Keep conduits as short and straight as possible.
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Breakers - Purchase circuit breakers that match the amperage rating of the circuit wire. They're designed to trip before dangerous overheating occurs.
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GFCIs / AFCIs - Install these advanced outlets and breakers to prevent electrocution and electrical fires.
The few extra dollars spent per component pays off exponentially in safety. With quality supplies in hand, let's walk through wiring a basic light switch.
How to Wire a Light Switch
Light switches seem simple, but improperly wiring one can lead to dangerous consequences. Follow these steps to safely wire a light switch:
1. Turn Off Power at the Breaker
Safety first! Locate the circuit breaker controlling the light, flip it to the "Off" position, and verify power is off with a voltage tester. Remember to take this one crucial first step any time you work on electrical projects.
2. Choose an Appropriate Box Location
Most switches mount into a standard single-gang electrical box. Choose a spot on the wall with:
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Clearance - At least 1/2" depth to fit the box and wires.
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Accessibility - The height should be conveniently reachable.
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Level surface - Make sure the box will mount flush on the wall surface.
3. Install the Electrical Box
Securely mount the electrical box in your chosen location. Having a sturdy, straight box ensures the switch won't wobble or crack down the road.
4. Run Power into the Box
Run the power source cable (typically 14/2 Romex) from the breaker into the box. Leave at least 6 inches of extra wire in the box.
5. Run Switched Wire to the Light
From the switch box, run a 3-wire cable up to the light fixture. This provides power to the switch, and from the switch up to the light.
6. Prepare the Wires
Strip off 1/2" insulation from each wire. For the ground wire only, also bend the exposed copper into a hook shape.
7. Connect the Wires
Following wiring diagrams for a basic single-pole switch, connect the hot (black), neutral (white), ground (green/bare), and switched (black) wires securely with twist-on wire connectors.
8. Mount the Switch
Connect the ground wire to the green screw or metal frame of the switch. Then screw the switch into place on the electrical box.
9. Test and Finish Up
Re-check all connections, restore power at the breaker, test the switch, place wire nuts over connections, coil extra wire neatly in the box, and screw on the switch plate.
Take it step-by-step and you've successfully wired a light switch! Apply these same principles to wire additional switches, outlets, and fixtures.
When to Call an Electrician
While the basics like switches and outlets can certainly be DIY projects, more complex electrical work should be left to the pros. Call a licensed electrician for:
- Major rewiring jobs
- Installing new circuits or subpanels
- Hot tubs, swimming pools, and outdoor wiring
- Whole house generator installations
- Knob and tube wiring replacements
- Troubleshooting tricky electrical problems
Though wiring costs can add up, the safety of your home and family is invaluable. If a project gives you any doubt, hire a professional rather than taking risks.
Conclusion
With proper education, the right materials, and a methodical approach focused on safety, an ambitious DIYer can successfully wire many basic electrical projects in their home. But complex tasks require the expertise of licensed electricians who have years of training and understand the electrical code. If tackling any major electrical work, consult with your local building department to ensure you follow all codes and get the necessary permits and inspections. The initial investments of time, money, and caution when dealing with electricity pay back exponentially over the life of your home.