blowing light issue

[gto4evr]

Hello all,

great forum! I've got a problem I'd like advice on. I've got a light at the bottom of the stairs wired with a 3 way switch so it's controlled by both a switch at the top and at the bottom of the stairway. This light eats bulbs pretty quickly. I rarely get a month out of a bulb. I've changed the light fixture itself, tried lower wattage bulbs and recently I just tried one of those LED style lights. The light from the LED was horrible so I didn't stay with it, but one thing I noticed is that when I screwed the light in, the LED's glowed very dimly with the light "off" When on, it came on fine but when off, the dim glow. I screwed the LED light into a standard lamp fixture and it didn't glow at all when off so I'm guessing it's either something to do with the 3 way wired switches or it's showing some problem as to why I keep blowing standard light bulbs every 3 weeks. Any ideas?

Thanks,
Dennis

[HayZee518]

the typical wiring path for three way switches is: a two wire feeds one box. the black of the two wire goes to the odd screw on the three way, the white of the two wire and the white from the three wire is spliced together. this carries the neutral on to the other switchbox. the three wire black and red connect to the switch. these are called travelers. at the other switch, the three wire white connects to the load cable [two wire] white. the red/black travelers connect to the remote switch brass screws. the load cable's black connects to the odd colored screw on the remote's switch. current path at any given time is from the odd colored screw through either the black or red to the other switch. depending on that switch's position it is either on or off. if you flip this switch to the other position, the first switch determins whether the circuit is on or off.
as far as your problem, try a flourescent compact bulb or look on the incandescent package for the bulb rated at 135 volts.

[gto4evr]

Thanks for the response. I've checked the wiring and it is wired correctly. The position of one switch governs the other as in flipping one up, the other one going up will turn the lights off and vice versa. I guess the main thing bothering me is the dim glow on the LED light when the fixture is off. Is it possible one of the switches isn't cutting the circuit completely when it's "off" and that's wearing out the bulbs even though the regular incadescent bulbs are not showing any glow? I get no dim glow on the LED light when I screw it into a standard 2 wire switched outlet. I don't know if that's a symptom of a problem or an affect of the reversing polarity on a 3 way switch -- I know it doesn't matter which sides hot or neutral are on a standard light but maybe it does matter with an LED?

edit: forget the polarity, I just checked and I get the dim glow on the LED in both directions for off (both switches up and both switches down)

I just put a meter on the fixture. 000.0 volts when it's off, nothing there to make the LED glow so what gives? On the flip side of that, I've got 130.9v when I turn the fixture on. I just checked some other outlets around the room and it's all spitting 130 -- Doesn't that seem high as it's supposed to be 110 isn't it?

[HayZee518]

LED lights are basically DC powered. Individual LEDs draw about 1.2 volts and the amps is in the milliamp range [thousandth of a amp] LEDs that operate on 120 volts have many individual bulbs connected series and series parallel to equal the input voltage with a diode to change the AC to DC with a current limiting resistor in series with the string. LEDs are very sensitive to voltage and it doesn't take much to cause them to light. they operate very similarily to a neon bulb. the neon gas inside the bulb ionizes and glows around one electrode. the LED has a junction, not necessarily gas filled but is made up of two dissimilar materials. One readily gives up electrons, one accepts electrons. This junction is called the doped region of a semiconductor.
130 isn't that bad. any range from 117 to 132 is nominal. buy bulbs rated the max of 135 volt and you shouldn't have problems.

[gto4evr]

Thanks for the info Hayzee -- I'll look for some 135w bulbs, the Home Depot specials I buy say 120v on them so that extra 10 must be cooking them short.