t Ask a Trenton Electrician: What is Knob and Tube Wiring?
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Ask a Trenton Electrician: What is Knob and Tube Wiring?

Posted on January 31, 2014 by admin in Electrical, Rewiring

What is knob-and-tube wiring exactly? It’s an outdated method of electrical wiring found in homes built before the year 1950.  The name comes from the ceramic knobs that support the rig and the ceramic tubes that protects the wiring. The primary difference between today’s wiring and knob-and-tube style is that the black and white wires are separated and spaced a few inches apart in knob-and-tube. In modern wiring, the black wire, white wire and ground wire are all packaged in a single cable. The way the wires are insulated is different too: modern wiring is insulated with plastic; knob-and-tube with rubber. The problem is that the rubber insulation is wears away over time. This is often the reason that knob-and-tube wiring finally needs to be replaced.

Another reason that replacing knob and tube wiring often needs to be replaced is that the wire is older and has been in service for many years. This can make for the inefficient and unreliable conduction of electricity. Another reason is the lack of a ground wire, which creates an emergency path for stray electricity that can prevent electrocution. Modern wiring has a ground wire whereas knob-and-tube wiring does not.

Some of the other common problems you may come across with knob-and-tube include:

  • Poor Connections: The majority of problems with knob-and-tube wiring almost always result from faulty connections made during the original installation.
  • Damage: By definition, knob-and-tube wiring is old. That means it has probably been subjected to the clumsiness of multiple amateur handymen on top of decades of wear and tear.
  • Brittleness: The rubber insulation on knob-and-tube becomes brittle over time. The wiring can often become brittle in high heat areas, including connections above ceiling light fixtures.

If your home is still powered by knob and tube wiring, you are just asking for trouble. Call Raynor Services and learn how we can help you rewire your home!