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Dinsdale
11-12-2002, 03:12 PM
We recently bought this lamp.
http://www.bearsinthewoods.net/shop/tiffanylampsfavrile1409.html
As you can see, this webpage says that it takes 6 - 25 watt bulbs. That is what they told us at the store. When we unpacked it, though, the lamp itself said it took maximum 15W bulbs.
We called the store, and they said they'd check with the manufacturer. They said the one they have on the floor has been burning 25 watters since they got it in many months ago. I sent the maker an e-mail as well.
I guess I'm a wimp about such things, but I'd just as soon not go out of my way to increase the chances of home fire or shattered glass.
What's the dope, folks? How important is the maximum wattage limit on lamps? If you exceed the max, how much do you increase the likelihood of what?

Nametag
11-12-2002, 03:46 PM
It's a matter of resistance. Thin wires resist the flow of electricity more than thick ones, and respond to excess load by getting hot. If you exceed the total rated wattage for the lamp, the wires may get hot enough to melt the insulation, burn the insulation, and/or start a fire. The question is how much excess capacity did the mfr. build into that lamp? I wouldn't count on the shop's word or their one lamp when it comes to something like that. The total difference in wattage is 60 watts, which is definitely enough to make a difference.

Crafter_Man
11-12-2002, 03:58 PM
Lamps imported from China often have overly-conservative wattage ratings. (Dale Tiffany lamps are manufactured in the US but assembled in China.) For example, if the lamp is designed for a maximum of 100 W, the documentation will usually say “60 W,” or something like that. Not exactly sure why this is done; maybe it’s a customs thing. Anyway, the upshot is that you will have no problem using 25 W bulbs, IMO.

Uncommon Sense
11-12-2002, 03:59 PM
I agree, the manufacturer had the thing UL tested, not the store.
Tho nothing would probably happen since 60 watts is only 1/2 an amp. The sockets themselves are each rated at 15w. Who knows what guage wire the lamp in internally wired with? Go with the socket rating.
If the fixture is designed in such a way that the bulb heat can`t readily escape, that makes this wattage rating even more important.

Crafter_Man
11-12-2002, 04:09 PM
Originally posted by Nametag
It's a matter of resistance. Thin wires resist the flow of electricity more than thick ones, and respond to excess load by getting hot. If you exceed the total rated wattage for the lamp, the wires may get hot enough to melt the insulation, burn the insulation, and/or start a fire.

Nonsense. The weak link is not in the wires; if each bulb had a 25 W rating, the current would be 0.21 A rms per bulb, and 1.25 A rms total. This is not enough current to generate appreciable heat in any wire under 22 AWG. (18 AWG is probably used in this lamp.) When it comes to lamp wattage, the manufactured is most concerned about heat conducted into the screw base and heat radiated into the globe.

Again, I highly doubt you'll have a problem w/ 25 W per bulb...

casdave
11-12-2002, 05:04 PM
There is one other possible issue but it is very unlikely to be too much to worry about.

If the appliance has 3 core wiring, then all 3 cores will have the same gauge.

The thinner the wire the greater the resistance, so it follows that the earth path will have a higher value.
It is just about possible in an aging or poor house wiring installation that this, when added to the house earth path, would mean that if a fault should occur that it would not blow the fuse quickly enough for safety.

For this style of light though, having a total of six 25W lamps is a little over the top unless you have an inline dimmer control as it is as much about creating a low level output for mood and decoration rather than lots of bright light.

It may well actually look a lot better with a low light output

That's a lots of ifs and buts though and doesn't directly have a bearing on the alp ratings, except that the lower the total current for the lamps, the lighter gauge you can get away with for the mains lead, which makes it a little cheaper to produce.

On such low levels of lighting on individual lampholders I cannot see too much problem with 25W jobbies, now if you were maybe working with lights that used larger Wattage lamps, say a max of 100W per holder, then going up to say 150W would be a bad idea.

No Dragons Here
11-12-2002, 05:07 PM
I have to agree with Crafter here. Wires from the base to each socket/bulb are not going to be the weak point here. It could be the wire from the base to the wall socket, but even that is doubtful. A quick check shows that a lamp cord sized 18 AWG (40 mils or 1.024 mm) is good for 10 amps. At 110 volts 10 amps gets you 1100 Watts, which is way more than you need. This means wire is probably not the issue.

Looking at the picture, I would bet they are worried about heat damage to the fixture's finish or the gold favrile glass. If this is just for decoration then go with the 15 watt bulbs. If you actualy want to see with it then go with the 25 watt bulbs and replace it when it gets ugly.

Dinsdale
11-12-2002, 05:18 PM
Man - you guys are talking to a LAWYER here - which means I have absolutelyt NO practical knowledge! After the holocaust, all you folks with practical knowledge will be looking at me as food! All your numbers and such are making my head spin.

I just wanna know if this thing is gonna burn my house down (and if so who I could sue) - OR if it is gonna get damaged such that the missus will have an excuse to go out and spend even MORE money to replace it (meaning I will have to inflate my bills a little more.)

Seriously, thanks for all the input. While we don't really need a ton of light from it, the 15s make it essentially a glorified nightlight. The 25s give an acceptable amount of light. The 15s, not enough.

Crafter_Man
11-12-2002, 05:47 PM
If it were me, I would use 25 W bulbs. Trust me on this, nothing bad is going to happen.

Think about it: if using 25 W bulbs constituted a serious hazard, then 15 W would be “right on the edge.” If that were the case, there would be no way in hell they’d rate it for even 15 W.

(To the naysayers: Yea, yea, I know a 25 W bulb puts out 67% more heat than a 15 W bulb. But we’re talking about relatively low wattages here, and therefore only absolute values are to be considered. For all but the most exotic fixtures, 25 W ain’t nothing…)

Uncommon Sense
11-12-2002, 06:27 PM
Agreed With CRAFTERMAN. You can grab a lit 25w. bulb and unscrew it with your bare hands. DO NOT go higher than 25w. tho. And put the damn thing on a dimmer so you get the full range of effects. They even make 6 foot lamp extension cords with the little roller dimmer built into the cord so you won`t have to replace your wall switch with a dimmer.

kanicbird
11-12-2002, 08:22 PM
you should have no prob's with 25w but if you are that worried you could use halogen 15w bulbs which should give you about 20w of 'normal bulb' light which is close.

if you can get a compact florcent light those 15 watts would give you about 50w of 'normal bulb' light

I am Sparticus
11-13-2002, 01:12 AM
I replaced all my house bulbs with screw in flourescent. Much brighter, about a quarter of the electricity used, much as K2dave suggests. I would not, however, use halogen bulbs, as their surface gets really, really hot from my experience. The wattage for halogens in my experience is really off for the heat on the surface. I had always thought that watts were heat, but after using some halogen bulbs for while, I just decided they were too dangerous to hands that might touch them.

David Simmons
11-13-2002, 01:29 AM
I don't think that the current rating of wires, etc. is the problem.

A question: Are the bulbs enclosed or out in the open? If enclosed is the enclosure complete or is it open at the bottom? Are there holes in the top to allow air circulation past the bulbs?

If the bulb is enclosed in some sort of lamp shade and the circulation is poor the bulb will run hot and thus shorten bulb live.

If the helical flourscents will fit I would certainly use them. They run a lot cooler and use a lot less power. For example a flourescent with light output equal to a 40 watt incandescent will only use about 10 watts. The power ratio is about 4 to 1 for all types.

Uncommon Sense
11-13-2002, 08:24 AM
Remember that you can`t dim flourescent bulbs. ( if your considering that option). Also, flourescents may look a little tacky in this particular fixture. (IMHO). The best look would be a 25 or 20w. flame shaped bulb. (IMHO)

Mangetout
11-13-2002, 08:39 AM
Nice lamp.

I'd go with the suggestion to use fluorescents; you can get 'candle' (http://www.waiyat.com.hk/cat_general/Catalog_11.htm) types now that are only 3W and they have an equivalent light output to 15W filament types.

Mangetout
11-13-2002, 08:42 AM
There are also such things as dimmable fluorescents, although I'm not sure if they are available in candle packages...

Dinsdale
11-13-2002, 09:03 AM
Thanks, guys. This is the kind of lamp where the choice of bulbs makes a considerable difference in the overall appearance. So I will rely upon the consensus wisdom of the millions (at least the 5 or 6) and just go with 25s. Now for the next question, frosted or clear? ;)

Thanks again.

GaryM
11-13-2002, 09:17 AM
Originally posted by whuckfistle
Remember that you can`t dim flourescent bulbs. ( if your considering that option). Also, flourescents may look a little tacky in this particular fixture. (IMHO). The best look would be a 25 or 20w. flame shaped bulb. (IMHO)
I was at Costco on Sunday and noticed that they had a four pack of candlabra based flourescent bulbs on the shelf. IIRC they were 15 or 25 watt equivilent.

Squink
11-13-2002, 09:53 AM
Before ignoring the sticker on the lamp, you might check the rating of the lamp's power switch.
There are lots of cheap 1 amp switches out there, and they will blow if you put too much current through them. I recently had to replace a switch rated for 3 amps that was mounted in a lamp labeled 500 watts max. Of course no reputable lamp manufacturer would ever cut costs just by installing a cheaper switch. They’d also change the label on the fixture. ;)

Uncommon Sense
11-13-2002, 10:37 AM
DINSDALE - I think CLEAR would be the choice since the lamp has the colored glass thingies on it already. Clear would give the appearance of "more" light.

Dinsdale
11-13-2002, 10:50 AM
With clear, you could see the element rather brightly. With frosted, you could see the entire outline of the bulb.
I strongly expressed my preference for clear, which pretty much ensures the missus will go frosted!

You know, when I was a kid - or even a single guy, I couldn't have imagined the amount of mental effort I'd be expending on household lighting...

Next up, mica!

Thanks again, folk. I'm further rationalizing going with 25s as my opportunity to live life on the edge! Just about as reckless as this old fart gets. Pretty soon I'll be tearing tags off of mattresses.

ftg
11-13-2002, 10:55 AM
I strongly urge against go over the recommended voltage. Going over can be a serious fire hazard. The most likely problem is the type (or lack of) "insulation" around the base. A good lamp has a ceramic base. A cheap lamp has a metal base sometimes with a cardboard tube around it to "protect it". I have taken apart many a lamp and found the cardboard significantly charred.

I have also seen a lot of lamps where the insulation on the wires at the ends where they connect to the base to is melted or charred.

Going over the rec. voltage is a "Darwin Award" action. Do not go over and please, please, please do not recommend to others that they do so. This is flat out stupid.

Uncommon Sense
11-13-2002, 11:38 AM
Have a fire protection contractor come in and install a sprinkler system with one head directly over the lamp. That way when the scorching flames reach the head the blaze will be put out. Or you could build a seperately enclosed room for the lamp with a Halon fire suppression system installed. Either way you should be safe.
Then you can put 1000w. bulbs in each socket.

Uncommon Sense
11-13-2002, 04:10 PM
FTG - We were not suggesting DINSDALE goes over the recommended "voltage" as you claim. The wattage of the bulbs was in question not the voltage.

Dinsdale
11-13-2002, 04:50 PM
So now I read THIS on-line.

Beware of "decorator" bulbs of all types, including candle-flame shapes. Most are made (and marked) for use in "tips up" position only. Never install candle-type bulbs with the tips down. Besides being counter-intuitive (flames going down?), antique fixtures with exposed down-pointed sockets were designed to use the globe-shaped bulbs we sell.

Stupid lamp.

Crafter_Man
11-13-2002, 05:36 PM
Originally posted by Dinsdale
So now I read THIS on-line.

Beware of "decorator" bulbs of all types, including candle-flame shapes. Most are made (and marked) for use in "tips up" position only. Never install candle-type bulbs with the tips down. Besides being counter-intuitive (flames going down?), antique fixtures with exposed down-pointed sockets were designed to use the globe-shaped bulbs we sell.

But what's the reason? Is it because the sharp point might jab somebody?

Mangetout
11-14-2002, 07:04 AM
Originally posted by Crafter_Man
If it were me, I would use 25 W bulbs. Trust me on this, nothing bad is going to happen.

Think about it: if using 25 W bulbs constituted a serious hazard, then 15 W would be “right on the edge.” If that were the case, there would be no way in hell they’d rate it for even 15 W.This is pretty much what I told the police last night; "Look Mr Police Officer," I said, "If driving at 90mph on the motorway is such a serious hazard, then the posted speed limit of 70mph would be 'right on the edge' - there's no way in hell you'd let me drive at even 70mph if 90mph wasn't completely safe, anyway, shouldn't you be trying to catch some real criminals?"