so i’ve got a client with some buzzing can lights on a dimmer switch. i understand the buzzing comes from the filament in the bulb vibrating due to the fact that the dimmer is cutting the current down. getting a new dimmer seems to be the key to fixing it, but can anyone suggest a style or brand that is immune to this problem? The current dimmer is a home depot Lutron model. Thanks for any suggestions.
brad
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Replies
switch is overloaded and getting too hot...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Forget the primal scream, just ROAR!!!
there are six cans each with either a 50W or 75W bulb (i can't remember at the moment). would this much load really be overloading a dimmer?
Yes, the dimmer could be overloaded. They usually have a label on them that says how many watts they can handle. You're talking at least 300 watts and probably more, and some dimmers are rated for 300 watts or less.
even a 600W switch could be overloaded....Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
yup...Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
Are the lights buzzing or the switch itself?“The richest genius, like the most fertile soil, when uncultivated, shoots up into the rankest weeds..” – Hume
DIIK...Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
DIIK?“The richest genius, like the most fertile soil, when uncultivated, shoots up into the rankest weeds..” – Hume
Danged If I Know.
"I cut this piece four times and it's still too short."
somebody has to...Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
the buzzing is coming from the lights themselves. the dimmer itself is quiet.
Some bulbs are quieter than others, as John mentioned. The better the filament is supported, the less it will buzz, all else being equal. The expensive Phillips R-30 lamps from HD are much quieter than the cheap Feit R-30's from the same store.Bill
Our GE Reveal bulbs hum like flourescents on a dimmer.Troy Sprout
Socialism in general has a record of failure so blatant that only an intellectual could ignore or evade it."-- Thomas Sowell
cheap bulbs...
go with a Philips R-30.........Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
Hey Marty, I have a humming/buzzing switch. It is clearly the switch, not the bulbs, that buzz. It doesn't buzz at all WHEN THEY ARE ON FULL POWER.There are six 60w bulbs on that switch. I don't understand how my problem could be overloading, but then I'm no EE.Damn. Now I'll have to do somthing about it. <G>
"Doubt is not a pleasant condition, but certainty is absurd."
~ Voltaire
get a better dimmer switch...Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
Any chance do you have one of those newer flourescent bulbs in one of the fixtures?
My dimmer started buzzing once I put one of these in. “The richest genius, like the most fertile soil, when uncultivated, shoots up into the rankest weeds..” – Hume
I'll check. Thanks for the suggestion.
"Doubt is not a pleasant condition, but certainty is absurd."
~ Voltaire
The buzz is worst mid-way thru the dimmer's range. When it's on full, it just passes everything thru. When it's off, it's off, there's nothing happening.
The dimmer works by turning off every time the AC goes through zero volts, then waiting a while before turning on and continuing with the 60 Hz. sine wave. How long that while is, is what you're adjusting with the knob or slider. The electromagentism that yanks on stuff and makes it buzz is proportional to the rate of change of Voltage, so there's much more of it during the brief periods when the triac turns on and re-joins the sine wave. The farther it is from the sine curve, the longer those jumps take, and the more magnetic energy there is. So it's loudest and worst at 90 degrees.
-- J.S.
Thanks for the post, even though I don't know enough to understand most of it.
"Doubt is not a pleasant condition, but certainty is absurd."
~ Voltaire
I doubt that triac or associated circuity it making the noise. But I suspect causes is that many of the units have chokes in them to reduce RFI and that choke has a loose core or loose mounting. And it is being jerked around by di/dt..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
mnn,
I thinks he said that it is the sharp voltage/current spike caused by the triac that is creating the magnetic pulse that is driving the vibrations of things like a choke or core.
SamT
Anyone who doesn't take truth seriously in small matters cannot be trusted in large ones either. [Einstein] Tks, BossHogg.
Edited 2/16/2007 12:02 am by SamT
Yes, exactly. The choke is the only place in the dimmer where a significant amount of energy could make the electrical to magnetic to mechanical transitions. That and bulb filaments are the potential trouble spots.
-- J.S.
The main culprit is the tightly coiled filament in the bulb. It acts like an electromagnet, and gets pulled towards the steel of the can. Rough service bulbs don't use tight coils, so they tend to buzz a lot less. Fixtures that put a lot of distance between the bulb and any big sheet steel parts would also help.
-- J.S.
i just have regular soft-white light bulbs in there now while we are painting and doing trim because we don't have the finish trims installed yet. i'll see if it helps with the real par 30's in there before i go switching out the dimmer. thanks everyone
If the client is habitually dimming the bulbs to less than 50% of their desired light output the on-off action of the dimmer can cause the filaments and the bulbs to vibrate. That Lutron dimmer is most likely rated for 600 watts total so probably not overloaded. Have your client replace the bulbs with lower wattage bulbs so the dimmer is normally not cut to less than 50% of light output and the problem will go away.
That'll work if they can live with the reduced maximum output. We may have the lights dimmed quite low for much of the time, but then turn them up full for clean-up when the party's over.
-- J.S.
Former client asked me if I had any idea why her switch was buzzing, even when flipped off at night. It's apparently sporatic, and occasionally wakes her up. I had no clue, I'd never heard of a switch buzzing. Would swapping the dimmer be the solution?
If it was OFF then there should not be any buzzing with either a plain switch or a dimmer.Was it something like a X-10 switch or anyother kind of "electronic lighting control system"?My guess is that it was not the siwtch, but something else that was transfered to the studs by the switch.Maybe a bee hive in the attic..
.
A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Bill and others,
I've experienced the same problems with dimmers as described here -- the buzzing is worst at low light settings and (nearly) goes away when turned up to full.
I replaced the bulbs with the 3-way variety and the buzzing all but disappeared.
Does that make any sense to anyone from a theoretical perspective?
Question2: what will eventually happen to a dimmer switch if it IS overloaded?