Electrical Contractor Explains Types of Home Wiring
More than 30 million homes, or about one-third of the homes in the United States are at least 50 years old, and studies have shown that the frequency of fires in these aging homes is disproportionately high. Many older homes were built with electrical systems and components which are no longer safe and may be considered as fire hazards.
Fire and other electrical safety concerns may arise due to aging, improper installation and alteration, or misuse. It is important to identify what type, color, and size wire is needed in order to properly address hazardous situations before they become critical.
Knob & Tube Wiring: 1800s–1930s
Knob and tube wiring was designed as an open air system that used ceramic knobs to separate wires from combustible framing. These suspended wires were directed though ceramic tubes to prevent contact with the wood framing and starting a fire. Today, knob and tube wiring is considered a fire hazard because it is not a grounded system, and is more susceptible to damage from aging and faulty renovations.
Aluminum Wiring: 1960s through 1970s
As the price of copper soared in the 1960s, it became commonplace for home electrical wires to be made using aluminum instead of copper. It is estimated that nearly two million homes were wired with aluminum between 1962 and 1972.
As aluminum is exposed to air over time and begins to oxidize, the electrical resistance in the wiring begins to increase and causes the wiring to burn hotter, creating a greater fire hazard.
If your home is equipped with aluminum wiring, consult with an electrician about updating the wiring system.
To further minimize the dangers of aluminum wiring in your home:
- Cover exposed aluminum with special anti-oxidizing paste.
- Ensure that all receptacles, switches, or other electrical devices have terminals that prevent contact between the aluminum and the copper-alloy terminals of the fixture.
Grounded Electrical Systems: 1940s through Present
Electricity always seeks to return to its source and complete a continuous circuit. A typical circuit in your home has two conductors: hot and neutral. Electricity travels from the service panel to home appliances through the hot conductor, and returns the current to the main service panel through the neutral conductor. A third or “grounding” wire is also connected to all outlets and metal boxes in your home.
This critical safety feature is designed to greatly reduce your chance of shock or electrocution should a short circuit occur. Grounding wires are connected directly to the earth through a metal grounding rod or a cold water pipe. Should a short circuit or an overload occur, any extra electricity will find its way along the grounding wire to the earth.
Grounding is an essential safety feature. If your home does not have this protection, contact us or callprofessional about bringing your home’s wiring up to date.
Note: It is important that you hire a Certified Electrician for your electrical wiring upgrades. Safety First!
Statistics courtesy of the Electrical Safety Foundation International