Knob and tube wiring - extending a circuit

Electrical · Lights, Outlets and Switches · printed page 102 (PDF page 103)

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Book index entries

Connecting a New Circuit Electric Knob-and-Tube Wiring Knob and Tube Wiring

Text in the illustration

two junction boxes (with a connecting wire between them) are required to properly tap into existing knob and tube wiring because there isn't usually enough slack in the old wire to make the all of the connections in one box
flooring
junction box
connecting wire
joist
bring wires in through separate holes in the junction box and provide bushings to prevent mechanical damage to the old wire
circuit extension or new wire extending circuit

Generated explanation

The illustration shows an extension of existing knob-and-tube wiring along a joist beneath flooring. Two junction boxes are linked by a connecting wire, with the existing separate conductors entering the outer sides of the boxes near their insulating knobs. A new circuit-extension cable leaves the right-hand box and passes through the joist. The annotations explain that two boxes accommodate the limited slack in the existing wiring and that old wires should enter through separate holes with protective bushings to prevent mechanical damage.

Components

knob-and-tube wiring insulating knobs junction boxes connecting wire circuit-extension cable wire-entry bushings joist flooring

Materials

wood ceramic insulators insulated electrical wiring