Bulbs burning out frequently??

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jahilliard

Senior Member
I've got a friend that has mentioned several times that the bulbs all around his house never last more than 6 months. He has explained that it doesn't matter if it's the bulbs in his fan lights it recessed lights or exterior ltg...or halogen or incandescent etc. He wants me to come by and check things out but I was curious if anyone has experienced the same thing or had to troubleshoot a similar scenario??
 

GoldDigger

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Well, first check the service voltage. These days incandescent light bulbs are about the only loads that are sensitive to small (5-10V) overvoltage.
Possibly the tap on the local POCO transformer is set incorrectly.
Be sure to get measurements at different times over a 24 hour period, since the voltage may change with total load in the area and possible timed tap changes by POCO.
 

jahilliard

Senior Member
I was under the impression that bulbs are regularly rated at 130V to avoid that as well as adding life to the bulb. Is that not accurate?
 

GoldDigger

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I was under the impression that bulbs are regularly rated at 130V to avoid that as well as adding life to the bulb. Is that not accurate?
That is not accurate. You can get bulbs rated for full life in hours at 130V if you want, but the choices will be more limited and you will not find them at the neighborhood store.
Normal bulbs will deliver their rated life at 120V. And each 5% increase in voltage above that will cut the life in half.
A line voltage of 132 volts will cut the life by a factor of 4.
Given that all of the bulbs seem to be showing similar life reduction I would vote for voltage.
 

Dennis Alwon

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I wish someone would step in and make it illegal to sell 120V bulbs. They are a waste. Of course soon it wont matter as incandescents will be gone and LEDs don't seem to mind the higher voltages.

I also second the use of 130V bulbs
 

JDB3

Senior Member
Friend just called me that he has some fluorescent lights in I think cove lighting. Said that they were real dim. Replaced the tubes & they got real bright for a bit, then dimmed back down. Also said, when he messes with them, they get bright for a bit then dim again.

I asked him to try to check voltage. Aside from that, do you think it might have something to do with the ground? :?
 

tom baker

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Ground, no.
When we had incandescent traffic signal lamps, they were 130 volts, 8,000 hours rated, We'd do lamp changes every year, the used lamps still had a lot of life in them, they would last forever.
All LED now.
 

mopowr steve

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NW Ohio
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Electrical contractor
One thing I've noticed is that the new halogen filament envelope being used in what appears as a normal everyday bulb we used to buy, states a life of approx. (.9 years). Put some in new construction and before I even finish the job I'll be changing a couple of them because they have blown.
Outside of that major contributing factors to filament style bulbs blowing prematurely are

1. Loose rivet in the socket connecting shell or pin of socket to power leads creating excessive arcing stressing the bulb.

2. To much vibration from construction activities, children and adults stomping and carrying on in the house, etc.

or unless you really do have a major voltage issue problem because of a bad neutral connection.
 

GoldDigger

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Part of the problem is that the .9 year life is probably specified at less than two hours per day.
Another issue with halogens is low voltage, especially if you dim them. Unless the inner envelope temperature gets high enough the halogen cycle cannot return evaporated metal to the filament.
 

Sierrasparky

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Electrician ,contractor
Part of the problem is that the .9 year life is probably specified at less than two hours per day.
Another issue with halogens is low voltage, especially if you dim them. Unless the inner envelope temperature gets high enough the halogen cycle cannot return evaporated metal to the filament.

Did not know this. I thought dimming made them last longer.
 

ActionDave

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Another issue with halogens is low voltage, especially if you dim them. Unless the inner envelope temperature gets high enough the halogen cycle cannot return evaporated metal to the filament.
Interesting. What does that do to the lamp? I have some halogens in my house on dimmers, they get used every day and have held up for at least ten years.
 

GoldDigger

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Interesting. What does that do to the lamp? I have some halogens in my house on dimmers, they get used every day and have held up for at least ten years.
The basic halogen cycle lets the filament run at a higher temperature without burning out too rapidly. The hotter filament gives more visible light per watt and "crisper" higher color temperature. But the rate of evaporation of tungsten from the filament increases with temperature even faster.
The halogen cycle does not slow the evaporation, but the tungsten vapor combines with the halogen gas to make a compound that will not stick to the inside of the other envelope when it is hot. Eventually the molecules hit the hot filament and break apart, depositing tungsten back on the filament and returning the halogen to capture more evaporated tungsten.
The problem is that if you lower the operating temperature a little bit the evaporation rate remains high but the wall temperature is so low that the tungsten halide stays deposited on the envelope and the filament gets thinner.
If you go even dimmer the evaporation rate goes down far enough that life starts to increase again. But by that point you no longer have any advantages over a non halogen bulb.

If you want to dim just a little bit you can restore life for the most part by turning them up to full brightness for an hour or two from time to time.
 
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mirawho

Senior Member
Location
Sun Valley, CA
Friend just called me that he has some fluorescent lights in I think cove lighting. Said that they were real dim. Replaced the tubes & they got real bright for a bit, then dimmed back down. Also said, when he messes with them, they get bright for a bit then dim again.

I asked him to try to check voltage. Aside from that, do you think it might have something to do with the ground? :?

You can run fluorescents off batteries so definitely not a ground issue, sounds like the ballast. I highly doubt they are not RS ballasts.
 

Electric-Light

Senior Member
One thing I've noticed is that the new halogen filament envelope being used in what appears as a normal everyday bulb we used to buy, states a life of approx. (.9 years). Put some in new construction and before I even finish the job I'll be changing a couple of them because they have blown.

Those use an extremely thin filament and unusually sensitive to vibration. They're EXTREMELY delicate. Flick it once while it's turned on and it's gone.
 
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