If you work on your laptop or read in bed, you usually have to reach under the shade, and turn off the lamp. Installing an inline lamp switch makes turning the lamp off easier. An inline switch controls the hotwire, the conductor attached to the blade on the male end of the cord, by stopping the current. Here are some tips to add an inline switch to a lamp cord.
Prepare to Work
For this project, you need: a tape measure, a voltage meter, wire cutters, side-cutter, a utility knife, a felt-tip marker, screwdriver, and an inline switch. Disconnect the cord from the outlet, and for extra safety, turn off the breaker to the room, and test the cord and outlet with a voltage meter to ensure no current runs to them.
Inspect the cord to verify it is polarized. Polarized cords have one wider prong with two smaller prongs that only fit one way into the outlet. Locate the hotwire by feeling for the smooth portion of the cord sheathing covering the wires. Choose where to place the in-line switch on the cord, which should be easily accessible.
Splice the Wires
Detach the switch by loosening the machine screw with the screwdriver, and mark the top and bottom. Set the part with the rotary dial aside in a safe place, so you won't lose the nut on the back. Measure a ¾ inch section of the cord, and mark two points.
Cut a one-inch slit in the middle of the points with the utility knife pushing the tip of the blade through the plastic. Follow the indented line in the wires, and avoid cutting into the wire insulation. Remove a ¼ inch section from the hot wire with the side cutters, and leave the neutral wire attached.
Install the Switch
Insert the cord in the channels of the hollow rotary case at the bottom of the switch. Push the top firmly on the base so the small brass spikes on the hot wire cut into the insulation, and so it contacts the copper strands on the inside. The cut wire goes into the channel divided by a plastic dam, and each wire should contact the dam.
Put the switch back together, fastening the screws and nut securely with the screwdriver, but not too tight, or you could damage the switch cover. Plug in the cord to test, and if it doesn't work, unplug the lamp, and re-tighten the screws.
Though installing an inline lamp switch is simple, working with electricity requires following safety measures and patience. If you don't trust yourself, or the light doesn't work, hire an electrical contractor like one from RDS Electric to find the problem.