Ask LiveJournal Electrician: light fixture maximum wattage?

[randomness]

We have this old swing-arm lamp that takes three position bulbs. The socket is stamped 250W 250V, but I can't tell if it's just describing the socket or if the wiring in the lamp itself is rated for 250W.

Most modern swing-arm lamps I've seen have a tag that says they're limited to 150W. I figured I'd ask around before I put a 250 watt bulb in it and started a fire. :)

Anyone have any thoughts?

Comments

[gravitrue.livejournal.com]

Wires are resistors. They waste some of the power that goes through them as heat. The thinner the wire, the more it will heat up given the same amount of power going through it. A heavy load will try to suck more power through. Suck too much power through and things can catch fire, or simply melt off the insulation and cause shock hazards.
A standard light socket does not magically stop power at some wattage cutoff, it starts heating up. Of course, it might start melting from the bulb's heat first, which also isn't going to improve its safety any.

A dimmer, on the other hand, does magically stop the power at a given cutoff; most dimmers work by switching the light on and off really fast.