Installing your own electrical system can be a great way to save money compared to hiring an electrician. However, electrical work can be dangerous if not done properly. This guide will walk you through the basics of residential electrical systems and provide tips for safely installing your own electrical wiring and components.
Understanding Electrical Basics
Before tackling any electrical project, it's important to understand some key concepts about how electricity works:
Electricity Basics
- Electricity is the flow of electrons through a conductor.
- Voltage is the force that pushes electrons through the circuit. Household systems use 120 volts and 240 volts.
- Current is the amount of electrons flowing through a circuit. It is measured in amps.
- Resistance slows the flow of electrons. Insulators like plastic have very high resistance.
- A complete circuit returns current to its source. An open circuit stops current flow.
Home Electrical Systems
- Electricity enters the home through service wires and passes through the electric meter and main service panel.
- The service panel uses circuit breakers or fuses to protect each circuit from overload.
- Common residential wiring is 14 gauge copper for 15 amp circuits and 12 gauge for 20 amps.
- Outlets, lights, and appliances connect to circuits fed by the service panel.
Planning Your Electrical Project
Careful planning ensures your DIY electrical project goes smoothly:
Evaluate Electrical Needs
- Decide what parts of your electrical system need upgrading. Common projects include adding circuits, installing new fixtures, or replacing the main service panel.
Obtain Required Permits
- Electrical work usually requires permits from your local building department. Failing to get permits can risk fines or issues when selling your home.
Create a Detailed Plan
- Draw diagrams showing the locations of circuits, outlets, switches, lights, and main service panel. Note wiring routes between them.
- List all required materials and tools.
- Break the project into logical steps.
Follow Safety Procedures
- Turn off power at the main breaker before starting work. Verify it's off by testing outlets with a circuit tester.
- Work on only one circuit at a time to avoid wires getting mixed up.
- Wear personal protective equipment like gloves and eye protection.
Consider Hiring an Electrician
- For major electrical work like upgrading the main service panel, hiring a licensed electrician is often wise. Get quotes to compare costs.
Installing and Replacing Outlets and Switches
Replacing worn outlets and switches or adding new ones is a common DIY electrical project.
Outlet and Switch Installation Tips
- Turn off power to the circuit and verify it's dead before starting work.
- Carefully remove the existing outlet or switch. Note existing wire connections.
- For new outlets, you may need to run additional wiring from the service panel or nearby outlets. Use approved NM cable.
- Anchor the outlet or switch securely in the electrical box and attach wires neatly using screw terminals.
- Attach the outlet cover plate and turn the circuit back on to test operation.
Common Outlet and Switch Projects
-
GFCI outlets - Install these outlets in kitchens, bathrooms, and other areas where outlets are near water sources to prevent shocks.
-
AFCI outlets - Now required in many bedrooms, these outlets protect against arcs and sparks that can cause fires.
-
Lighted switches - Handy for finding switches in the dark. Make sure to get compatible dimmer-type switches for dimmable lights.
-
Smart switches - Let you control lights via phone apps or voice commands. Require a neutral wire in switch box.
Running New Circuits from the Service Panel
Adding a new circuit enables you to supply power to additional outlets and fixtures.
Planning New Circuits
- Decide what areas need a new circuit - for example, the kitchen, a workshop, or addition.
- Calculate expected power demand to determine if you need a 15 amp or 20 amp circuit.
- Find an empty slot in the service panel for the new circuit breaker.
Running and Connecting New Circuits
- Turn off main power. Verify it's dead before working in the service panel.
- Run 14/2 or 12/2 NM cable from the service panel to the first outlet in the new circuit. Use staples to secure the cable.
- Splice in additional cable lengths to reach all outlets and fixtures for the circuit.
- Connect hot, neutral, and ground wires securely to outlets, switches, lights, and appliances.
- Attach the ground wire to all electrical box mounting tabs.
- Label all wires clearly indicating their circuit number.
- Install the new breaker in the panel and connect the circuit wires to the breaker terminals.
- Turn on main power and test the new circuit. Check outlets and lights for proper function.
Replacing an Electrical Service Panel
Upgrading an outdated main service panel improves safety and allows adding more circuits.
When It's Time to Upgrade Your Panel
- Old fuses keep blowing or breakers tripping frequently
- Not enough open breaker slots to add new circuits
-Parts are rusty or corroded - Still uses unsafe fusible links instead of circuit breakers
Hiring an Electrician Is Highly Recommended
- Replacing the main service panel is complex, dangerous work best left to professionals.
- An electrician will obtain required permits and coordinate with your electric utility.
What's Involved in a Panel Upgrade
- New larger-capacity panel installed to meet whole-house electrical demand.
- All circuits transferred over to new panel and properly labeled.
- Rewiring done as needed to install safety features like AFCIs and GFCIs.
- Service entrance wires and meter base replaced if undersized or in poor condition.
Helpful Tips for DIY Electrical Projects
Follow these tips to ensure success and stay safe:
- Purchase only UL-listed electrical parts and light fixtures.
- Take photos before disassembling existing wiring connections.
- Plan on needing more time than you expect - electrical work is tedious!
- Label all wires clearly to avoid confusion when reconnecting them.
- Do not attempt any project you do not fully understand how to do safely.
- Be sure to call for electrical inspections after you complete the work.
By carefully planning your project, following safety procedures, and getting professional help when needed, you can successfully upgrade your electrical system and save money in the process. But always put safety first!