The lamp that sits behind my desk and that provides the majority of the illumination when I’m working here started blinking infrequently the other night. At first I thought it was the normal power fluctuations we get here from time to time, but then I began hearing what sounded like something shorting out. I reached to turn off the lamp, and the steel base was very hot to the touch. Obviously, I unplugged the lamp.

I tore into it this evening, figuring it was just a fried switch. The switch is fried, no doubt, but I also found this:

The black wire in this connector comes from the AC power source. The red wire goes to the switch.

When I disassembled the lamp, the top of this connector was touching the metal base. At first I thought that over time a piece of metal inside the connector had rubbed a hole in the clear plastic insulation and came into contact with the lamp base, causing a short. But when I cut off the burned part, there was no metal sticking out. I can only conclude that the switch shorted out and the resulting heat traveled down the 4″ red wire to this connector, melting the insulation and allowing current to arc between the base and these two wires.

Looking more closely at the switch, I see molded into the back the words, INCANDESCENT ONLY, but I don’t see anything that gives a current rating. The fixture in question is a halogen torchiere floor lamp with a 300W bulb. These lamps are said by some to be a fire hazard, although those that I have meet the safety guidelines published by the CPSC.

I can’t say for certain that this switch is original equipment, as I obtained the lamp from a former employer when our office was closed. As far as I can recall, nobody there ever replaced the switch (it would have been out of character), and I certainly hadn’t taken the thing apart before.

I have two other lamps of this type. One of them had a bad switch when I got it, and the other has been working in my living room for at least 10 years. You can bet I’ll be looking into that switch soon, though.

Is it common for the switches in these things to burn out? [Note added later: It’s a three-position switch with off, low, and high settings. I almost always used the ‘low’ setting.]