The other day we put a bunch of recessed lights in a house. The guys didn't look at the labels on the bulbs and some different type bulbs were used. Most were 120 volt BR40 65 watt, a few were 130 volt BR40 75 watt, The 65 watt bulbs were much brighter. I know the 130 volt bulbs won't put out 75 watts unless the voltage is 130, but the difference was huge, the 75's looked like 40's compared to the 65's.

Why was the dif that large?

Light bulbs are much less efficient when run at lower than "nameplate" voltage. Where efficiency is lumens produced/watts consumed. The 130V bulbs will consume less than rated watts, and produce even less lumens than the ratio of reduced wattage would indicate. The main feature of 130V light bulbs is lifetime. The life of a bulb is roughly the ratio of (rated volts/operating volts)to the 6th power. That bulb at that firehouse is likely at a much reduced voltage.

wa2ise,

Just wanted to mention that I've been in touch with the "Curators" of the Bulb several times and they've assured me that it is on a normal voltage circuit. It was not even a (surge-protected) regulated one until recent years.

Bill

[This message has been edited by Bill Addiss (edited 05-06-2003).]

When I used to do traffic signal work we always used 130v bulbs because of the life expectancy.

I can also vouch for longer life expectancy of 130V bulbs vs 120V bulbs. About 18 months before we moved out of our previous house, we got a new garage door opener. It went through bulbs ( 120V ) at a rate of about 1 per month. I tried regular bulbs, appliance bulbs, and garage door opener bulbs. After that we had the garage door opener guy come back out. He replaced the light socket ( although he didn't really think that there was anything wrong with it ) and recommended using a 130V bulb. I put one in and it was still going strong over a year later when we moved out. I had a similar experience in our new house. We got new garage door openers and the original bulbs burned out very quickly. After replacing them once with regular bulbs, I got some more 130V bulbs and have not had one burn out in over a year.

The additional beauty of the 130-volt bulbs is that you can easily buy them from the dollar stores (four bulbs a box).

Cheaper than buying the name-brand bulbs from Walmart or K-mart (or wherever it is Middle-America shops at these days).

One of the 130-volt 60-watt bulbs that was in my entryway fixture died a few weeks ago after almost a YEAR and a half of heavy constant use.

Its companion is still going strong, supplemented by a similarly rated 40-watt (hey, it was all I had on hand at the time and besides, it's covered by a glass dish so who's gonna see! ).

[This message has been edited by SvenNYC (edited 05-07-2003).]

I have to throw my opinion in here. Use caution when buying lamps (bulbs) from the dollar store, I've seen import ones rated for 110V. They don't last long at all.

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I know the 130 volt bulbs won't put out 75 watts unless the voltage is 130, but the difference was huge, the 75's looked like 40's compared to the 65's.
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Remember, watts is a measurement of energy used, not the light output. Check the lumens on the package for rated light output, it does vary.

As I've heard it, the original reason for 130v lamps was to be used in industrial areas or areas close to the generating plant where the average voltage was somewhat higher, and that because of voltage drop, locations further out could use the 120v lamps, and it all evens out.

Kale,

That is my problem exactly, The transformer for my house is right outside of my garage. Plus I am the only one on the transformer. It puts out about 124-126 volts and the regular bulbs just don't last as long. I always use 130 volt. They seem to last a little longer.

The ANSI-standard acceptable voltage range usually contained in electric utilities' "service-conditions" fine print is around 110-127 volts at the meter.

Don’t overlook screw-based CF {compact fluorescent} lamps as incandescent replacements. Their lifetime seems very good and they are getting more price-competitive and closer to [traditional incandescent] “A19-sized” these days.

Kale:
Yup. I always pop open the box and check the print on the bulb. Also hold them up to the light to make sure that the filaments are intact (you can sort of see through the frosting).

It's not only off-brand dollar store bulbs that are sometimes rated for 110 volts, mind you. Last year I saw one supermarket in the Harlem district here in New York City that was stocking some 110-volt Sylvania bulbs -- 75 watt clear ones. Our voltage is roughly between 118-121.

Well known scam. I've told my mom about it also....

Hey, I wonder what makes the regular household General Electric 75 and 100 watt bulbs only last 750 hours while their (cheaper) off-brand competitors and even Ikea's rebranded bulbs last for, and have a life of 1,000 to 1,500 hours printed on the package? Hmmm....

GE _does_ stamp its bulbs as 120 volts....but the filaments are not properly supported (they sag and break) and I betcha they actually design the bulb for 110-115 volts. Crooks....

According to my little Osram Sylvana lamp dimming calculator here are the voltage relations:

130V lamp at 130V-100%light output, 100%wattage used, 100% life
130V lamp at 120V- 78% light output, 88%wattage used, 300% life
120V lamp at 125V-114%light output, 107%wattage used, 60% life
130V lamp at 125V- 88%light output, 94%wattage used, 170% life
110V lamp at 125V- 147%light output, 120%wattage used, 22% life

Hope this helps...

[This message has been edited by Mike Wescoatt (edited 05-10-2003).]

I've got to agree with Bjarney.
Get off of your "A-19" lamps...S

My personal problem with CFL's is that they ruin my AM radio reception at home...especially long distance AM reception which is bad enough because I'm fighting old elevator motors in my building whose ground connections have probably rotten away (if they even existed in the first place).

Also, the light they give out gives me a headache - it's not enough and at the wrong frequencies.

I prefer those long fluorecent tubes I have at work. They give out a much brighter and even light output. Only problem is when there's a loose connection at the ballast and they start buzzing.

Last year I asked one of the building electricians at work if they could check out one of the lights in my stock room because it was buzzing like a chainsaw.

[This message has been edited by SvenNYC (edited 05-11-2003).]