What is Knob and Tube Wiring?

When the wonder of electricity started to be brought into our homes in the late 1890s, the wiring system predominately used was referred to as “knob and tube wiring”. This wiring system was just the beginning of giving our homes the ability to deliver electrical power to serve our families.

As with most things, that system has been updated and improved several times over the course of 2 centuries. But you may be surprised to learn that it still exists and continues to be used in older homes across the country.

Construction

Rubberized cloth fabric was used to insulate each hot and neutral wire separately. The wiring was then run inside wall cavities. A porcelain knob was used to hold the wire in place. Unfortunately the insulation used at that time was only capable of doing its job for about 25 years. After that time, an increasing chance of failure is caused by cracking and wear.

Grounding

One of the major problems with knob and tube wiring is the lack of grounding. Today, our home’s electrical system is grounded in order to offer us protection from unwanted power surges and short circuits.  You can find out more about “What is a ground wire?” in one of our recent blogs.

While the knob and tube wiring was an inspired innovation of its time, they did not have the information to realize what a great importance our grounding system truly is in our homes.

If your home’s electrical system is in need of an upgrade, give us a call about a home electrical inspection. Douthit Electrical has been providing Charlotte with quality electrical services since 1990.


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