How to Safely Rewire Your Home Without an Electrician

Introduction

Rewiring a home can seem like a daunting task, but with proper planning and precautions, it is possible for a homeowner to do it safely without hiring an electrician. There are important steps that need to be taken to ensure you do quality work that is up to code and safe. In this comprehensive guide, I will walk through the entire process of rewiring a home, from understanding electrical systems and safety procedures to installing new wiring and components.

Understanding Electrical Systems

Before beginning any electrical work, it's crucial to understand how home electrical systems are designed and function.

The Main Electrical Service Panel

The electrical service panel, commonly known as the breaker box, is the central hub that connects your home to the main power supply. This panel contains circuit breakers that serve as safety switches, shutting off power to individual circuits if they are overloaded. The main service panel is usually located outside or in the basement.

Circuit Breakers vs Fuses

• Circuit breakers can be manually switched on and off and will automatically trip if a circuit is overloaded. They can easily be reset by switching them back to the on position once the overload is addressed.

• Fuses are one-use safety devices that melt and separate if a circuit is overloaded. They must be replaced with new fuses to get the circuit working again.

120/240 Volt Power Supply

Most homes have a 120/240-volt electrical service meaning there are two 120 volt "hot" wires and a neutral wire that combine to provide 240 volt power that large appliances require. There is also a ground wire for safety.

Copper vs Aluminum Wiring

• Copper wiring is the preferred standard today as it is a better conductor and safer overall.

• Aluminum wiring was used in some homes during the 60s and 70s. It is more prone to overheating and oxidation, making improper connections unsafe.

Safety Precautions

Working with electrical wiring can be extremely dangerous. Make safety your top priority with these precautions:

Turn Off Power at Main Circuit Panel

Turn off all power at the main circuit breaker panel before doing any electrical work. Use a contact voltage tester on wires to confirm power is off.

Use Personal Protective Equipment

Wear rubber-soled shoes, safety goggles, and electrical gloves when handling wires. Never work on live wires.

Install GFCIs

GFCI (ground fault circuit interrupter) outlets or breakers detect abnormal currents and shut off power in milliseconds if electricity flows outside normal paths. Install these for added protection.

Follow Codes

All electrical work should be done according to the National Electrical Code (NEC) and local building codes. Follow standards for wire sizes, connections, grounding and more.

Get Permits

Check with your local building department to determine if you need an electrical permit for home rewiring work. Permits ensure work is inspected.

Planning the Rewire Project

Careful planning is crucial to a successful rewiring project. These steps will help you develop a plan:

Evaluate Current Electrical System

• Assess the current condition of your electrical system such as age of components, presence of two-prong outlets, etc. This will help determine the scope of work needed.

• Use a voltage tester to check for power surges and drops which can indicate problems.

Determine New Wire Sizing

Evaluate electrical load needs room-by-room to determine proper wire size. Standard is often 12 AWG for lighting and outlets and 10 AWG for major appliances.

Develop Circuit Maps

Draw out circuit maps highlighting all outlets, switches, appliances, and lights on each circuit. This is essential for proper planning and installation.

Select New Components

Choose what type of wiring (copper or aluminum), breaker panel, receptacles, light switches, etc. you will use. Stick to standard matching colors (black, white, green, bare copper) for wires.

Create a Timeline

Factor in time for getting permits, hiring electricians if needed, the rewire process, and inspections. Rewiring a whole house can take several weeks to months.

Safety Checkpoints

Plan for installation of GFCIs, AFCIs (arc fault circuit interrupters), tamper-resistant outlets, and hardwired smoke alarms. These are now required by code.

Removing Old Wiring

Once planning is complete, it's time to remove old wiring. Take the following safety precautions first:

• Turn off all power at the main circuit breaker panel.
• Use a non-contact voltage tester to confirm wires are de-energized.
• Wear personal protective equipment like electrical gloves.

Then you can start removing old wires:

• Remove outlet and switch cover plates.
• Disconnect wires from devices like receptacles and switches using needle nose pliers.
• Pull wires out of electrical boxes carefully to avoid damage.
• Coil up wires neatly as you remove them to prevent tangles.
• Dispose of or recycle old wires properly. Copper can be recycled for scrap value.

Inspect electrical boxes as you go and replace any that are damaged or corroded.

Installing New Wires

Once old wires are removed, you can start installing new wiring. Here are the step-by-step instructions:

Select Proper Wire Size

Refer to your circuit maps to choose the correct wire size for each circuit. Typical sizes are 12 or 14 AWG for outlets and lighting. Use thicker 10 AWG for major appliances.

Run Cables Through Walls and Ceilings

Carefully run new NM (nonmetallic) cables through wall cavities from the panel to each outlet or switch. Use staples to secure cables every 4.5-6 feet.

Strip Wires Properly

Strip about 1/2 inch of insulation from wire ends using wire strippers. Avoid nicking or cutting wire strands.

Make Secure Connections

Use wire nuts to connect matching wires securely at outlets, switches and terminals. Follow diagrams properly for hot, neutral and ground wires.

Anchor Cables at Boxes

Anchor cables firmly to electrical boxes using cable clamps. This prevents strain on connections.

Label Circuits Clearly

Use circuit directory labels inside panel and outlet covers to identify each circuit clearly. This makes future troubleshooting much easier.

Helpful Tips and Warnings

Here are some additional tips to follow and mistakes to avoid when rewiring your home:

• Never work on live/energized wires. This could result in severe shock or electrocution.

• Test wires with a non-contact voltage tester before touching them when power is turned back on.

• Use the "pigtail" method to connect multiple wires instead of chaining them.

• Avoid using wire nuts rated for fewer connections than needed.

• Place cables entering the top of the panel first to avoid crossing live bus bars.

• Consult an electrician if you don't understand the panel wiring. Mistakes can be deadly.

• Check your work thoroughly before turning power back on to identify and fix any problems.

Inspections and Completing the Project

You're almost done! Follow these final steps once the new wiring is installed:

Hire an Electrician for Inspection

Many pros offer inspection services to check DIY electrical work before the city inspection. This guarantees your work passes on the first try.

Request City/County Inspection

Contact your local building department to schedule the required final inspection by the city/county electrical inspector. There is normally a fee for this.

Make Any Required Changes

If anything fails inspection, make the necessary fixes and schedule a re-inspection when complete. Common fixes are minor labeling and securing cables.

Turn Power Back On!

Once approved, turn the main breaker back on at your panel. Then flip individual breakers on to restore power room-by-room.

Add Finishing Touches

Install any missing switch/outlet covers, light fixtures, etc. Test all electrical devices to ensure proper function. You did it!

Conclusion

Rewiring your home is an ambitious project, but it can be completed safely by a homeowner if proper precautions are taken. The most important steps are to turn off power at the main breaker, wear protective equipment, follow electrical codes, and get your work inspected. While challenging, a home rewiring project allows you to upgrade and take ownership of your electrical system.