Introduction
Rewiring a home can be a daunting task, but with proper precautions it can be done safely without the risk of electrocution. Electrocution was more common 100 years ago before safety standards and building codes were established. By following modern electrical codes and best practices, you can avoid tragic electrical accidents while upgrading the wiring in your home.
Reasons for Rewiring
There are several reasons you may need to rewire your home:
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Upgrading to a 200 amp service - Many older homes have 100 amp electrical service, which may not be adequate for running multiple appliances and devices simultaneously. Upgrading to 200 amps provides capacity for more circuits.
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Aluminum wiring - Aluminum wiring was used in some homes in the 1960s and 1970s. It is prone to overheating and arcing, so rewiring with copper wiring can prevent fire hazards.
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Knob and tube wiring - This outdated wiring from the early 20th century lacks grounding and sufficient insulation. Replacing knob and tube wiring reduces fire and shock risks.
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Electrical code updates - Newer electrical codes require safety features like AFCI circuit breakers and GFCI outlets. Rewiring allows your home's electrical system to meet modern safety codes.
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Smart home technology - Rewiring enables you to install smart switches, outlets, and integrated home automation systems.
Dangers of Old Electrical Systems
Outdated electrical systems in older homes present multiple dangers:
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Insufficient circuit capacity - 100 amp service often has too few circuits resulting in frequent tripping of breakers.
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Unreliable connections - Loose, corroded, or substandard connections can overheat and cause fires.
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Lack of grounding - Ungrounded wiring does not provide a safe path for fault currents. This increases the risk of electrical shock.
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Damaged insulation - Brittle or damaged wire insulation exposes bare conductors creating shock and fire hazards.
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Absence of safety devices - Old systems lack modern GFCI and AFCI protection devices that prevent electrocution and detect dangerous arcs.
Safety Gear for Rewiring
Use personal protective equipment when rewiring to avoid electrical shocks, burns, and other injuries:
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Electrical gloves - Insulated rubber gloves rated for the voltages you are working on.
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Eye protection - Safety glasses or goggles in case of arc flashes.
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Long sleeve shirt and pants - Avoid exposed skin that could contact live wires. Wear non-conductive, flame-resistant fabrics.
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Work boots - Rubber soled, non-conductive boots help prevent shocks.
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Knee pads - For working in crawl spaces and tight areas.
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Face mask - Prevents inhalation of insulation particles and dust.
Safe Rewiring Steps
Follow these safe practices when rewiring your home:
1. Turn Off Power
The first step is to shut off power at the main breaker panel. Use a contact voltage tester to confirm power is off before working on any wires or connections. Lock out and tag out the main breaker panel.
2. Remove Old Wiring
Carefully remove existing knob and tube or obsolete wiring. Use caution when pulling wires out of boxes and removing them from the structure.
3. Install New Wiring
Run new wires according to code requirements. Use only copper wiring with sufficient gauge (thickness) for each circuit's amperage load. Use non-combustible insulation like THHN wire within wall cavities.
4. Connect Devices and Outlets
Follow wiring diagrams carefully when connecting switches, outlets, appliances and fixtures. Use wire nuts or other approved connectors. Pre-twisting wires helps make very tight connections.
5. Grounding and Bonding
Properly ground all circuits with ground wires attached to metal electrical boxes. Connect all boxes using grounding pigtails and bonding jumpers.
6. Install Safety Devices
Install AFCI breakers and GFCI outlets according to code requirements to protect against arcs and ground faults.
7. Inspect and Test
Inspect all wiring and connections carefully before turning power back on. Then test all outlets and devices while hot to verify proper function.
8. Close-Up and Finish
Secure wires inside boxes and panel. Install box cover plates and securely fasten the cover on the breaker panel box. Restore insulation, drywall and finishes.
Rewiring Old Homes is Best Left to Professionals
While rewiring is a DIY project you can tackle, it may be best left to trained electrical contractors who are familiar with local codes and safe practices. They have the right tools and PPE for the job as well. The risks of electrocution, fire, and costly mistakes are high. Unless you are a very experienced electrician, hire a pro to rewire your old home safely.
By following modern electrical codes and safety procedures, you can upgrade your home's wiring without the electrocution risks of the early 20th century. Rewiring improves safety, allows for expansion, and enables smart home capabilities. But due to the inherent hazards working with electricity, make safety your top priority.