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PTN
Incandecent Buzzing

I had a question regarding a couple of torchiere lamps i bought at home depot which use a three way switch for a three way bulb - 50, 100 and 150. i plugged them into outlets controlled by lutron dimmers and even when they are full-on, they buzz. When you dim them, they buzz louder.

i have several other hanging fixtures controlled by these same type of dimmers and there is no noise at all. Is this a function of the lamp wiring or maybe the type of bulbs?

i don't want to use them if i keep getting the annoying buzzing.

Thanks for any advice.

kentvw
Re: Incandecent Buzzing

Might be the dimmer but more than likely it’s the way the filament in the bulb is supported. Here’s a pretty good article on dimmers. Follow it down a ways and mention is made regarding buzzing.

http://www.epanorama.net/documents/lights/lightdimmer.html.old

dhvozza
Re: Incandecent Buzzing

I don't think it's a good idea to have an outlet controlled by a dimmer.If you plug in a vacuum or anything other than an incandecent light,you could burn it up.Have you tried the lamp in a unswithed recepticle?:confused:

unregistered
Re: Incandecent Buzzing

i'll skip the issue of using a dimmer to control a receptacle and what can happen when you plug in an inductive load rather than a purely resistive load except to say (i haven't checked the later versions) that the 2002 NEC at 404.14(E) prohibits this common (DIY) bad idea, and remind you that 15 amps x 120 volts = 1800 watts, and doubt your lutron dimmer switch is rated that high or listed to control a receptacle (or other than lamp loads).

3-way bulbs should only be dimmed when first set in the brightest setting (largest and longest outside looped fillament and only by a dimmer unit designed to do so (otherwise the other filaments will vibrate due the drops in the curent cycle that's why you're hearing a ferrad-like hum).

your lamp should work with a regular lightbulb on the second click from off (normally the medium light level on a three-way bulb), this way with a single filament you won't be subject to the other filaments vibration hum.

there are plug in dimmers available for lamps (some with remotes) some especially designed to work with 3-way lamps. a regular on/off switch controlling the receptacle and a plug-in dimmer might be a wiser choice for plug-in lamps. such a device pluged inline with your lamp and the receptacle controlled by a regular snap switch or hard-wired would safer for your house and your device wiring, should you plug anything other than a lamp or similar in plugged into your present (possibly unsafe and likely illegal) dimmer controlled receptacle.

PTN
Re: Incandecent Buzzing

thanks for all the advice.

the lamp i have plugged into an outlet is the only thing this outlet will ever have plugged into it and is behind a heavy piece of furniture so i know it can't be mistakenly moved and some how the outlet used for another purpose. i even plugged the other opening. This gives me some piece of mind as i understand what can happen if the wrong equipment is plugged into this outlet.

the three way bulb i am using was set on the brightest setting and it still buzzed so as was stated, the other filaments must be the culprits. i will purchase a single filament 150 watt buld and try it.

the only thing i don't understand is why the lamp should be set on the second click from off as opposed to the third click if the bulb only has one filament. how does this work in a three way switch?

i am relatively confident that the dimmer is not the problem and that it is in fact the filaments vibrating because i have a wireless plug in dimmer in another room which does not have a switched outlet using the same kind of lamp. This dimmer causes an even louder buzzing than the one i first mentioned above.

Again, i will try what was suggested using a single filament bulb but i would still like to understand why to use the second click setting.

Thanks again.

unregistered
Re: Incandecent Buzzing

because the second on setting or middle is the only one that will line up with the contacts to light a regular single filament light bulb in a 3-way lamp socket. when you install the regular bulb you will see, the others won't light the bulb. just make sure that you return the switch to the actual off setting when you wish the lamp off not just a single click to the high setting, otherwise the socket remains energized which could present a problem for example a broken bulb or a finger in the socket where the bulb should be.

since your outlet is not easily reached suggest you use a surge strip or switched extension cord so you will be able to safely unplug the lamp to service it (clean it or replace a light bulb).

since your 50-100-150 lamp suggest you use a 100 watt rough service bulb your middle position switch is rated for 100 watts. a rough service bulb has a stronger filament which can hold up better to the interupted cycling of being dimmed and generally they are the same size as a 3-way regular bulb (longer neck) so you shouldn't have contact to the lamp by the bulb issues.

still feel strongly that you should use a regular switch on the wall for on/off and a plug-in dimmer made for a lamp with or without a remote control. your use of a dimmer to control the outlet is not a good idea even as you plan to have it blocked from others, and may void your homeowner's insurance should you have a claim.

dhvozza
Re: Incandecent Buzzing

That's true,I have a 3-way lamp and the bulb went out.I only had a regular 60watt A19 bulb to replace it with.Now the lamp only works in the middle switch position.

PTN
Re: Incandecent Buzzing

servicing the lamp safely is not a problem because the dimmer switch has a disconnect feature that cuts the power to whatever is being controlled by the dimmer just for the ease of servicing.

i understand about the line up of the contacts but doesn't the entire socket have to be rated at 150 watts if the max bulb you can use is 150 - not just the third position of the switch?

i should be able to use a regular 150 watt bulb without any issues, no? i also will not be using the switch on the lamp because i have the dimmer on the wall for control.

i will have to check into the insurance issue though.

Thanks again for all the advice.

PTN
Re: Incandecent Buzzing

tried a regular 150 watt bulb (not 3-way) - same buzzing

Debra
Re: Incandecent Buzzing

I'm confused, why would you inflict dimming on a fixture that has 3 way settings?

Those settings are intended to give 3 lighting options. Those settings are not intended to operate the bulb at lower power levels the dimmer provides. The buzzing is the indication that the bulb and fixture are struggling to "live up" to their potential not survive on the meager power you're insisting they work on.

How would you like it if I told you that you could only have 50% of the air, water, and food you would normally require. I think you would do more than buzz.

You have a choice, either get a different light fixture without the 3 way setting option or get rid of the dimmer.

Mastercarpentry
Re: Incandecent Buzzing

I'm with ASC2078, get a top quality dimmer and that should end the problem. Also try the lamp in an undimmed circuit in every switch position and see what happens. If it still buzzes it's in the lamp; if it quits it's in the dimmer. Be sure the outlets are wired correctly as to polarity and be sure the dimmer is installed correctly too.

A side note is that 'touch' lamps can emit a virtual chaos of radio frequency energy and make radios, phones, TV's, computers, amplifiers and much more do strange things. Being a radio nut, you couldn't give me one of them! There may be an interaction with one of these causing the buzz if you have one nearby, even if it's in a different room as walls are pretty much transparent to RF energy. If you suspect this unplug the 'touch' device and see what happens.

MC

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