How to Safely Replace Electrical Wiring in Your 150 Year Old House

Replacing the electrical wiring in an old house can be a daunting task, but with proper planning and precautions, it can be done safely. Here is a step-by-step guide on how I went about replacing the wiring in my 150 year old house.

Assessing the Existing Electrical System

Before beginning any electrical work, it's important to understand what you're working with. Here are some key things I did to assess the electrical system:

• Checked the electrical panel - I looked at the condition of the electrical panel, noted what type it was (fuse box, breaker box), and documented what circuits were connected to it. This gave me an overview of how the house was wired.

• Mapped out all visible wiring - I went room by room and mapped out where all the wiring was run, including outlets, light fixtures, and switches. I drew up a diagram marking all the wiring runs.

• Determined wiring type - Based on the age of the house, I assumed the existing wiring was cloth-insulated copper wiring. This old wiring is prone to deterioration and poses a fire hazard. Replacing it was a must.

• Checked for knob and tube wiring - Some very old homes have an obsolete knob and tube wiring system. This type of wiring needs to be completely removed and cannot be worked with. Thankfully, my home didn't have this.

• Tested circuits for faults - I used a voltage tester to check for hot wires and faulty circuits. Any dead outlets or lights were noted.

Creating a Replacement Wiring Plan

Once I understood how the existing wiring system functioned, I was able to map out a plan for the new wiring:

• Met with an electrician - I consulted with a licensed electrician and we reviewed my assessment notes. He provided recommendations on the best way to rewire the house.

• Upgraded electrical panel - Based on my home's electricity needs, the electrician advised upgrading the 60 amp electrical panel to a 200 amp panel. This involved installing a new panel and service line.

• Mapped out new circuit routes - Taking into consideration all the outlets and fixtures I needed powered, we mapped out an optimal layout for running the new wiring through the house.

• Determined locations for switches/outlets - The new layout optimized placement of outlets, switches and fixtures for ease of use and aesthetic look. I identified all locations for these on the house map.

• Estimated wiring and breakers needed - Based on the new circuit routes, we made a list of all the wiring and circuit breakers that would need to be purchased.

Safety Precautions

Replacing old wiring brings inherent risks. Electrocution or fire caused by faulty wiring can be fatal. I took the following precautions to ensure safety:

• Turned off power at the main breaker - Before any work, I shut off all power at the main breaker panel. I also turned off individual breakers.

• Tested wires before touching - I used a non-contact voltage tester to double check that wires were dead. I never assumed a wire was safe.

• Wore electrical gloves - When handling even dead wires, I wore thick rubber electrical gloves to prevent accidental shocks.

• Had a fire extinguisher nearby - As an extra precaution against electrical fires, I kept a fire extinguisher handy in the room I was working in.

• Only worked on small sections at a time - I disconnected and replaced wiring in small sections, typically only one room at a time. This prevented getting overwhelmed.

• Secured exposed wires - Whenever I had to expose wires, such as when removing old wiring, I capped them and secured them to prevent accidental contact.

Step-by-Step Rewiring Process

With my plan in place and safety gear ready, I was ready to get to work. Here is the process I followed to rewire each room:

1. Turn Off Power and Inspect Wiring

I turned off power to the room at the breaker box and tested wires with a voltage tester. I removed cover plates and inspected the condition of the old wiring.

2. Remove Old Wiring

I disconnected the old wires from outlets, switches and fixtures, capping off wires as I went. I then carefully pulled the wires out from the walls and ceilings.

3. Run New Wiring and Secure

I measured and cut new 12/2 NM cables as needed and ran them through the walls securely using staples. I took care to leave 8-10 inches of extra wire at outlet boxes.

4. Install New Outlets, Switches and Fixtures

With the new wiring in place, I installed all the outlets, switches, light fixtures and other devices I had previously mapped out.

5. Connect New Wiring and Devices

Following wiring diagrams, I securely connected the new wires to the outlets, switches and fixtures, matching wire colors consistently.

6. Turn Power Back On and Test

Once everything was connected, I turned the power back on and methodically tested every outlet, switch and fixture. I also checked for secure connections by gently tugging wires.

7. Install Cover Plates and Wrap Up

With the new wiring tested and working, I installed new cover plates on outlets and switches. I repeated this process for each room.

Final Safety Inspections

After completing all the rewiring, I took these final steps:

• Had the licensed electrician inspect all my work
• Had the electrical inspector from my city inspect the full rewiring job
• Fixed any issues or made changes recommended
• Had the utility company turn power back on once approved

Replacing old wiring is a project that should only be done by qualified electricians. By carefully mapping out the project, taking all precautions, and having professional inspections, I was able to successfully rewire my 150 year old home safely. Always get the proper permits and have licensed electricians do this type of complex electrical work.