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How to Wire a Knob and Tube

Knob-and-tube wiring was used for residential electrical systems from the early 1900s to the 1940s. The name references the wire-fastening system that was used. The ceramic knobs are the supports for the wires on the joists and wall framing and the ceramic tubes were used when a wire penetrated any wood surface. This type of wiring uses only two conductors. The black hot wire delivered the power to the device, and the white neutral wire provided the path back to the source.

Things You'll Need

  • Noncontact voltage detector
  • Wire strippers
  • Screwdriver
  • Outlet
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    • 1

      Turn off the power for the circuit you are working on at the electrical distribution panel. In a knob-and-tube wiring system, this requires removing the fuse for the correct circuit by unscrewing it.

    • 2

      Confirm the power is off by touching a noncontact voltage detector to the wire's insulation. If the detector beeps or illuminates, there is still power in the wires.

    • 3

      Strip 3/8 inch of insulation off the black and white wires with wire strippers.

    • 4

      Loosen the brass hot and silver neutral terminals on the outlet with a screwdriver.

    • 5

      Wrap the black wire around the brass hot terminal and tighten it down.

    • 6

      Wrap the white wire around the silver neutral terminal and tighten it down.