I see so many ceiling fixtures with Max 75 watt written on them, and I really want to put a 100w in it for more light. whats with the fixture designers ????
– don’t they know 100 watt bulbs are common?.
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They are smart enough to know that 100 watt bulbs can make enough heat to start a fire, especially in ceiling fixtures. Most that I see are labeled 60 watt maximum. The design is on purpose to save people from their own ignorance and the possible effects.
Put in a hundred watter and the tongue contact at the base of the socket will deform from the heat and move away from contact turning the light off eventually. You will then be cussing out the manufacturerr who put "cheap" metal in the fixture without realizing that he may have saved your life.
Excellence is its own reward!
Put in a hundred watter and the tongue contact at the base of the socket will deform from the heat and move away from contact turning the light off eventually. You will then be cussing out the manufacturerr who put "cheap" metal in the fixture without realizing that he may have saved your life.
Interesting, I hadn't heard about that, but it sure makes sense._______________________
"I may have said the same thing before... But my explanation, I am sure, will always be different." Oscar Wilde
Bob, At least twice a year, someone asks me to fix a light fixture in their ceiling. Nine times out of eight, it has 75 or hundred watt bulbs with the little warning tag right there saying not to go over 60. I test to be sure the power is off to it and then unscrew the bulb, reach my finger tip in and tweak the tongue up a little. Then I screw in a sixty watt bulb and turn on the switch. "Hey! How'd you do that man?"
I smile and tell them that they are forbidden to use more than 60 and they say, "Yeah, sure"
More than one or two 'fixes' like this and it's time for a new fixture. I think the metal gets fatigued easy and reacts sooner from the heat.
.
Excellence is its own reward!
BTW, Need more light? Install more fixtures. It's hard to get old. Believe me< I know!
LOL
Excellence is its own reward!
Put in a compact flourescent 100 watt equivelant. They create a lot less heat. Though I don't think they're as bright as a regular 100 watt bulb.
Most/all CF' recommend against putting in enclosed globe type fixtures. Anyone know why this is?
Billy,
A bulb should not be in contact with anything. If it is, it will shorten it's lifespan. Since most fixtures are designed for incandesant bulbs and the Flourescent ones are larger, there is a good chance they will be in contact with the lens or globe..
Excellence is its own reward!
piffin, 4LORN,
wondering if you might know something.
I am really sold on the halogen bulbs that screw into a regular light socket. Nice tonal properties, bright for the wattage, etc. They take a little getting used to. I really don't like the flourescents for the light quality. So I assume the halogens have a transformer winding and diodes in the base to convert to DC. But I would not think they produce harmonics, i.e. function electrically much the same as an incandescent.
The flourescents on the other hand introduce a choppy digital wave form into the return current due to the ballast in the bulb base and the way it works. My question is there are convenient light accessories - for example, a remote control on/off that looks like a regular wall plate with a piece that the lamp screws into and it screws into the base. Or motion detectors for closets, etc.
They all tend to say: incandescent only. And I know it's because the flourescent bults screw with their digital circuitry (harmonic buzz), but the halogen's wouldn't do this woudl you think? In the midst of this long typing I thought hmm, maybe I should call the mfg with that question.
Anyway, g'day -
remodeler
The "light bulb style" of halogens don't have a transformer. It is just a filament connected to 120. The different is in the gas that is used in the bulb and the design of the filament to run at higher tempatures.
It should work with any device that say for incandencents.
That said those devices will, most likely, work with the CFL's also. I think that those warnings are more of a CYA because they never know when someone will use the scewin plug adapter and try to plug in a 1000 watt heater or a motor.
Specially with the CFL's with electronic ballast. I have been run one for about 3 years on a photocell that says for incandencent only.
However, you don't want to operate any of the CFL's on a dinner unless you get one (and there are a few) that specify that they are designed to work with a dimmer.
Flourescents need full a 120 volts to turn on is the short answer. A dimmer cuts the voltage to the lamp. Harmonics might add into it but the biggest issue is striking up the starting circuit on a flourescent. It just doesn't work well if at all.
Specialty flourescent ballasts can be dimmed with specialty dimmers. Modern institutions and offices have light level sensors in order to balance natural light with overhead flourescent light. Costs are into the 300 to 800 dollar range for a typical office setup to control supplementary lighting for presence & natural source balancing. Well beyond a homeowners typical need or budget.
Fun fact on the incandecent and Halogen lamps with dimmers. If you dim the lamp by 10% you increase the life by 50%. Voltage is the filaments enemy. The dimmer cuts the volts at the lamp.Jack of all trades and master of none - you got a problem with that?
> Fun fact on the incandecent and Halogen lamps with dimmers. If you dim the lamp by 10% you increase the life by 50%.
This isn't linear through the whole range of the dimmer, and halogens are a special case.
Tungsten halogen quartz incandescents get their long life by keeping the quartz envelope hot enough that tungsten vapor doesn't condense on it during operation. If you dim the halogen enough, you'll defeat that and get some blackening of the envelope. That blackening is tungsten that came from the filament. SOP for halogens that have been dimmed is to run them at full power for a few minutes before turning them off to get the tungsten back in circulation. Some of the larger ones we use, 5,000 to 20,000 watts, can have price tags in the four digit range, so it's worth a gaffer's while to enforce this.
Ordinary tungsten argon borosilicate incandescents -- which is what household light bulbs are -- can't take advantage of this because the borosilicate glass would melt before it was hot enough to prevent tungsten condensation. For them, dimming reduces the rate at which you fling tungsten off the filament.
As for wanting more light than the fixture is rated for, your best alternative is to use portable lamps. Get a desk lamp with a porcelain socket that's rated for a 150 watt reflector flood, and you can have 20 times the light you'd get from over-lamping a ceiling fixture. Light varies inversely with the square of the distance from the source.
-- J.S.
The increased life as I understood it from our lighting sales manager is the reduction of the voltage input tends to preserve the fillament longer. Your point is taken on the tungsten vapor.Jack of all trades and master of none - you got a problem with that?
About 10 years ago we did a $60,000 fire repair on a home which was only about 5 years old. The family had purchased the home 3 or 4 weeks before the fire. I asked the fire marshal about the cause, and he told me it was a recessed fixture in the bathroom on the second floor. Later I asked the homeowner about the cause of the fire and she told me that shortly after they moved into the home, she changed every lamp in every recessed fixture to 100w incandescent (not halogen) to get more light. Apparently, the high heat sensor in one of the fixtures failed. Poof ! No more roof on the house ! We all put a lot of faith in those sensors......
carpenter in transition
My point exactly- they all ought to be good for 100w
If they could build them to a 100 watt standard for no extra cost, you'd be right. But they can't. It costs more to build a 100 watt fixture than it does to build a 60 watt fixture, and there's no reason why the people who can read the directions should have to pay that cost just to protect the people who can't or won't read the directions.
I think there is some physics involved with 100 watt vs 60 watt fixtures. There is 40% more heat produced no matter how well built the fixture is. The heat has to be dissipated somehow, and the only practical method is to increase the fixture size proportionally. So the 100 watt fixtures would be pretty big. Then someone would wonder why they don't take 150 watt lamps.
It is not so much them building a fixt. that can handle 100 watts, it is that the bldg materials surrounding said fixture can scorch and start a fire. So it would necessitate a change in many of the bldg codes to accomodate a 100watt light bulb.
Concise and right..
Excellence is its own reward!
My point exactly, People who choose to ignore printed instructions and warnings deserve to be burnt out. Darwin wins!.
Excellence is its own reward!
Halogens, at least most of them, run on 120v unrectified. There are MR-16s ,commonly used in track lighting, and a few others that run on 12v supplied by a small transformer but all of the Edison base bulbs that I have looked at run on normal house current without the aid of a transformer.
The no dimmer for fluorescents, outside of those dimmers designed for the use and lamps also designed to be dimmed, rule comes, mostly, from the problems of starting. The ballast has to create an arc strong enough to jump the length of the tube. To do this it uses a specialized form of transformer, within the ballast to multiply the voltage. Most dimmers dim lights by reducing the voltage. This reduced voltage gives the ballast less to work with and can create a situation where it can't generate enough voltage to start.
Once the switch is on the ballast tries to start the lamp running normally. If it fails it tries again. This is like starting a truck with a big battery with the coil wire pulled. You crank and crank until the starter motor overheats and gives up. The ballast is not up to working that hard for long. It overheats. Most times a thermal overload kicks out, disconnects the power, and allows the overheated ballast to cool. Once cooled down it reconnects and the cycle starts again. Should the thermal overload fail closed, in the on position, the ballast will continue to cook and can leak, fail totally or even catch fire.
The no dimmer rule for halogens is a bit different. Halogens run hot, more on this later, hotter than most incandescent bulbs. They have to to generate the nice white light and last long. They last longer by way of the the halogen within the capsule rejecting the tungsten boiling off the filament and redepositing back on the filament. This makes the filament last longer even though it is running hotter.
When you dim a halogen bulb, and when you run it for a short period time, the capsule, a sealed borosilicate tube (Same material in an unfoamed state as the space shuttle tiles.) doesn't get up to operating temperature and tungsten vapor instead of being trapped by the halogen and put back on the filament condenses on the inside of the capsule. Also the filament runs cooler and gives off a much more yellow light. Largely defeating the advantages, longer life and better color rendering, of the halogen bulb that justify its higher price.
Be careful with halogen bulbs. Running hotter than most regular bulbs they can overheat fixtures. Especially enclosed ones. I bought one to put in a table lamp once. Seemed a good idea and the package had a picture of a lamp with a nice shade on it. After I got it home I read the fine print and find out that the bulb is not to be used with a shade. Evidently it runs hot enough to ignite some of them.
I'm not against halogen bulbs but as with anything that has higher performance it must be used with care. You don't loan out a GTO with a 454 to a 12 year old. Cheaper fixtures with lighter duty sockets, fully enclosed bulb locations and grand ma's table lamp with the tissue paper shade would not be, IMHO, good places to try out halogen bulbs. Particularly the higher wattage ones. Common sense goes a long way with this.
> Most dimmers dim lights by reducing the voltage
There are three main kinds of dimmers. Variable resistance dimmers are huge antique things that you might find in a really old theater installation. Movable tap transformer dimmers are also kinda large, Variac is the main brand name, and they do reduce (or even increase a little) the voltage while maintaining a true sine wave, as do the resistance dimmers. These are used for lighting in online bays and dub stages, where electrical noise is critical.
But the everyday household dimmers for incandescents are triac dimmers. They modify the sine wave in a strange sort of way. When they're on full, the full wave form pretty much comes through. But they dim using the fact that a triac turns itself off when the voltage of the wave passes through zero. As you turn them down, you're increasing the delay between the zero crossing point and when the triac gets turned on again. The neat thing about this wierd choppy wave form is that you're not dropping more than a couple volts across the dimmer in the on state, so you don't dissipate much heat and you can get 600 watts worth of dimmer in a single gang box. The downside to the choppy wave form is RF noise. The Triac wants to go from all the way off instantly to all the way on. Dimmer designers put an inductor (aka choke) in series with the dimmer to keep the noise down. Nonetheless, dV/dt gets extremely high when the triac turns on, and inductance being a function of the rate of change of voltage, inductive things like flourescent ballasts and motors get really hot due to the strange waveform from triac dimmers.
There are also special flourescents and special dimmers made to work together, but the ones I've seen didn't look so great, so I never bothered to find out how they worked.
> When you dim a halogen bulb, and when you run it for a short period time, the capsule, a sealed borosilicate tube (Same material in an unfoamed state as the space shuttle tiles.) doesn't get up to operating temperature and tungsten vapor instead of being trapped by the halogen and put back on the filament condenses on the inside of the capsule.
The envelope is quartz, not borosilicate. Borosilicate glass melts at too low a temperature. There are some lamps available, Phillips makes some called Halogena, that have a tungsten halogen quartz assembly sealed inside an outer borosilicate envelope. This eliminates the problem of fingerprints on the quartz, which will burn black and absorb so much heat that they melt the quartz. In the very early days of halogen lamps for motion picture use, they also made what were called "double jacket" lamps. I still have a 2 kW mogul bipost double jacket somewhere, kind of an antique now. Today the electrical crew knows to avoid fingerprints and wipe them off if they happen.
At full operating temperature, the halogen gas is saturated with tungsten vapor, which prevents additional tungsten from coming off the filament. Actually there's an equilibrium, a cycle of tungsten going back and forth between the gas and the filament. It's sort of like having a halogen atmosphere with 100% tungsten humidity.
-- J.S.
Here are several CFL's that are dimmable. Just screw them into sockets with standard dimmers.
They all look like the common CFL's.
Here's a dimmer tutorial with graphics.
http://www.ubasics.com/adam/electronics/doc/phasecon.shtml
Great definition on the dimmer logic.
I get nearly 3 classes a year on Variable frequency drives. Those devices provide control of motors thru similar PWM pulsed wave form modulation where the sine wave is sliced into 8 segments each side of the crossover. The space between the segments turning on and off determines the power transfered to the load. The Area under the curve is diminished relative to the frequency.( there is a relationship of volts to frequency that needs to be maintained for proper motor operation.) Sort of a least squares method of providing power. It seems Square D, Danfoss , Siemens, and a couple other manufacturers I get to represent, drill us to death on the details.
Now talk lighting, and it is training based on the PFM definition. Pure _ Magic. Generally, the rep that does the presentation is more concerned to cover the stocking program and available decorator colors than share the insight you brought out. Thanks John.
I am a bit curious on the voltage portion of this discussion. In the PWM drives there is a feature to boost starting voltage on a motor. Motors need the voltage level boosted to a larger value when starting at low frequency (>3hz) My assumption was that the segmented sinewave aproximated a reduction in voltage. In the PWM drives this appears true.
I guess I am unclear on the dimmer function. Have you come across any definitions on the dimmers that make this clearer?
Jack of all trades and master of none - you got a problem with that?
The link from Uncle Dunc above has real nice pictures of what the typical household dimmer does to the wave forms.
-- J.S.
I see said the blindman as he picked up his hammer and saw. The peaks don't diminish til past 1/2 dimming.
VFD's are sliced into 5 or more segments per 1/2 wave. (the more the better read $) There is a space between the segments of the 1/2 wave that grows with diminished power. In this case the power comes from a dc bus so zero switching is not and issue. Truely a different animal.
Great description.Jack of all trades and master of none - you got a problem with that?
You'd confused me at first, nope the bulbs don't contact anything. The new twisted style flourescents are about the same size as incandescents. Though I did use an old straight long tube one in a fixture where it touched in one spot. Got only 5 years or so out of it, maybe I was lucky.
The buildup of heat in an enclosed fixture will prematurely cook electronics in the CFL base.
Thanks, that makes sense. Guess I'll keep taking my chances. Most of my fixtures are enclosed, and I like them. If the electronics fry so be it, though they produce very little heat, it'd seem they should be able to easily handle that little bit.
Need to start dating them when I install them, if they fail quickly in enclosed fixtures, I'll have to quit using them.
Its all about balance. How much heat the bulb/s put out, the temperature at which the fixture and any surrounding materials degrade and how well the fixture design can dissipate any heat into the surrounding air.
Incandescent bulbs, lamps in electrician lingo, should rightly be called heat bulbs not light bulbs. Only around 13% of the electricity used comes out as light. The rest comes out as heat. The greater the watt rating the higher the heat output.
Many cheaper fixtures have sockets made of Bakelite, a thermoset plastic, shells made of aluminum versus brass and a generally thinner and light weight construction compared with more expensive models. The cheaper versions can handle less heat.
The fixture design can greatly influence how fast heat can dissipate into the air. A design with the lamps totally enclosed will heat up more than one with the sides or bottom open to the air.
In addition companies sometimes down rate their fixture to avoid possible legal liability. Stamping in a 60 watt maximum bulb warning is cheaper than having a justified 75 watt and going to court to prove the point. It's defensive.
For cheaper fixtures 60 watts is pretty standard. Higher quality, expensive, fixtures can have a 75 or 100 watt rating but I can't remember any noncommercial fixtures that were over 100 watts.
Compact fluorescent bulbs might help. If it will physically fit and the fixture is not controlled by a dimmer, most fluorescent don't do well with dimmers, you could go with a 150 watt equivalent and get more light.
Another possibility would be either a better, more bulbs and rated for higher wattage, fixture or more fixtures. If you have attic access to the area an electrician should be able to add fixtures quickly and for a reasonable cost.
Picture this. I come home after a hard day's work, and find wifeypoo sitting in the dark, with a scared expression. "Whats wrong honey?"
She tells me that as soon as she turned on the wall light, it exploded, and flames licked out of the wall four feet. I though, "Yeah right." So I flick the switch, heard the pop, whirled around, saw the sconce explode, and yes, flames shooting out of the wall four feet. "See," she said, "I told you so." There was a nice scortch mark 6" around the box.
OK, it seems that the light fixture was rated for 40watt, and we had a 60 watt in it. No big deal, but the insulators between the metal inner socket and the outside brass wall is merely very thin cardboard. The extra wattage cooked the cardboard black, and it ultimately disinegrated over time. The hot inner socket then shorted out the grounded brass outer socket, resulting in a nice fire. I have no idea why the breaker didn't trip, but I changed it out.
From this point on, I observe the wattage requirements of all lamps, AND, when replacing any bulb, I take off my glasses and closely inspect the cardboard liner. If necessary, I have a supply of those and some replacement sockets handy and change them out if they need replacing.
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1927
You just made me go check my bulbs.
All true but my question is why don't they design them all to take 100w bulbs?
That won't stop the 150 w bulb being installed but due to cost of those bulbs it would sure help a lot.
I think the bulb designers are fighting human nature.
Half the time the warning tags have been sprayed over with paint or are covered with sheetrock mud
>> ... why don't they design them all to take 100w bulbs?
The same reason they don't design all cars to go 140 mph. They'd cost more to build, and most buyers wouldn't want to pay the premium.
Just cheaper to build junk. Probably cost an extra nickle per fixture if they put a good bulb holder in it. Shaving pennies is big buisiness.
I just installed a ceiling fan, single bulb light kit, says 60 watt max on it. I need 100. It's retarded to design any single light fixture for only 60 watt bulbs.
Gonna replace the lamp holder under the globe. Wire with some 14 gauge or better. I have a good one sitting in a drawer. Not the 3 cent piece of garbage that came w/ the fan. Big glass globe can certainly handle heat from a 100 watter.
Just curious, why is it illegal to wire in a light with less then 14 gauge wire, yet when you get to the fixture they use 18 or 20 gauge. Doesn't that leave the possiblity of wires in the fixture melting down before the breaker can trip?
Oh, I do try to follow the guidelines. Removed the cover on one enclosed fixture, the wire was blackened and cracking. 100 watt bulb, not high temp wire (that'd cost a couple pennies). Not wire I'd ever use in AC house wiring period. Replaced the fixture w/ a better one. I'd say good one, but don't seem to see those much. Though some sure cost a lot more. A few have better quality, but, much of the time paying 3-4 times more for a fixture just gets you a different name on the box.
Think anytime I install a fixture, I'm gonna solder some 14 gauge wire on the socket. And replace the socket if it's junk. May be legal, but seems like a fire risk to me.
Frankly, we should require any fixture that can't handle above 60 watts to use small base bulbs so you can't overload them. At least I've never seen a small base bulb over 60 watts. At least in the future this fire hazard would lessen.
"Just curious, why is it illegal to wire in a light with less then 14 gauge wire, yet when you get to the fixture they use 18 or 20 gauge. Doesn't that leave the possiblity of wires in the fixture melting down before the breaker can trip? "
And it is UL Listed generally.
There are ratings for homes where anything that fits can be plugged into the wall logically. And there are ratings for appliances where power use is limited by the fact that this sealed appliance can't run anything else unless someone cuts it open.
It is all about application. I've paid for UL inspectors to come in and make sure a product built in a UL 508 shop meets the NEC and can carry a UL label. Approvals, listings, and functional capabilities are different worlds. You pay for the first, the part manufacturer pays for the second, and capabilities are always beyond what is approved or listed.
In my understanding UL is in Chicago because Capones men had to find something legit to do after prohibition. It is a confidence racket. There is a good side in that their approval is a point of reference for the casual consumer. However if you can tell a millivolt from a megawatt it is a confidence racket.
Depending on the wire material & insulation type an industrial version of 18 Ga copper wire can carry 18 amps in free air 90deg c max. Truely this is not for use in a home it is application oriented.Jack of all trades and master of none - you got a problem with that?
I worked for a company that builds custom computer controlled manufacturing equipment.
One of our customers insisted our equipment had to be UL listed or they wouldn't buy it.
We looked into it, it'd have cost us $10,000 plus to get the equipment UL certified. Of course the customer didn't want to pay for it. Told them it wouldn't be UL certified. Cancelled order. Reordered identical equipment a couple months later, with a new project leader, much easier to deal with.
We never could figure of what real benifit the UL listing would have. Look good in court if something bad happened???
Certainly wouldn't want to go through that process for each piece of equipment, did I mention it was custom?
UL listing is so that your product can carry the UL label every time it is made to that specification. They do all sorts of sometimes worthwhile tests that do shake out the problem with production equipment.
In the industrial world I trapse the UL label is affixed if the shop that builds the product has a UL 508 quality system and some formalized quality control program . It costs $ every year to keep the 508 status alive.
But there is more . All the parts that go into the cabinet have to be listed in the 4 big honking books that list UL tested parts. On top of that they have to be listed for an application. Industrial is the highest, appliance is another one. Industrial is kind of a stand alone classification that allows any combination of the 30 K parts as long as they are wired per UL now NEC standards etc. If sfor some reason you need to use TEW wire, that has an appliance rating not an industrial one. If that is the case then you need to add it to your companies "listings" A listing update costs 500 bucks 4 years ago. Now, you can add several (decades of) parts to the listing at one time but it still is 500 smackers. Estimate a 1200 dollar job and get hung with the 500 dollar listing update and you are hosed.
It is a confidence racket. maybe your computer system will blow up? if it has UL on it it might not. BS, the courts take care of the feable minded and the trecherous. It is a badge of legitimacy that is often earned, yet sometimes not.
I put sawn and split shakes on my cottage. how in the hell do you classify the tinder they are as UL. I started a roaring fire with the leftovers.
Legally there is probably a term for it but I believe it is just a liability spreader. it involves more people in the decision. TUV and ISO 900X are more of the same. I tell you theyu are the offspring of Al Capone. Just look at the suits the inspectors wear. It'll give you an indication of where the money is flowing. Unfortunately, there is no check to balance them.
Jack of all trades and master of none - you got a problem with that?
Edited 2/21/2003 6:47:40 PM ET by Booch