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Some of my bulbs seem to go very quickly whilst others last for years.



Eventually ,annoyed by what seemed to be more money down the drain it occurred to me that the fitting might be clogged with dead insects and cobwebby detritus.



I have examined it and ,yes it was .



Could this have caused the bulb to overload and so blow before its time?

You know might it have shorted the connections in a minor way but enough to overload the bulb?



Anyway , I have cleaned it now and if it seems effective ,I will go around the whole house looking for dirty fittings (dirty on the inside)

What type of bulbs?
FWIW, I've never known "normal" household muck around bulbs have any effect on the lightbulb life.
Some fittings, and / or places they are fitted, seem to chew through bulbs faster than others though.

2 Light fittings in our hall that seem to destroy bulbs much quicker than usual, regardless of type (LED, CFL or incandescent) it's on my list of jobs to do...

Dave54 wrote: ↑Tue Oct 06, 2020 3:32 pm What type of bulbs?
FWIW, I've never known "normal" household muck around bulbs have any effect on the lightbulb life.
Some fittings, and / or places they are fitted, seem to chew through bulbs faster than others though.

Not sure what type ,but not the incandescent ones as I don't see them for sale anywhere and bulbs are now a lot more expensive than they used to be.

The thing is ,though that really jogged me this time is that is went as I put it in and it gave a little spark.

Can't recall if the bulb had already gone and I was reinserting it in hope or whether it was still good (since I also turn it off by unscrewing the fuse which is located very close by)

If that was a short in the fitting it didn't blow the fuse but it did blow the bulb...

Can that actually happen?

I get lots of gunge in the light fittings because we have so many midges ,flies and moths that are attracted to it even indoors.

Edit

If it is not the gunge that is responsible ,why would some locations be harder on bulb life than others?

Multitude of reasons.
Heat, vibration, quality of lamp ............

as an aside
years ago lamp holders where brass and porcelain with a cloth shade so stone and metal brilliant for heat removal from the bulb so no overheating
as years progressed plastics come along so perhaps 20% replace as the porcelain bit turns plastic so a bit less heat removal
at the same time shades also turn to metal and glass so still cools as less airflow but plenty off heat sink ability
then you turn to a thin metal clip in the moulded now all plastic holder so give support to the bayonet pins in a glass lampshade so no real heat transfer as you have two power contact pins and the wire to take the heat away in an enclosed shade so lots off heat no heat sink and reduced airflow
you now have leds about 10% the power consumption for the same light with not even any volume off glass or metal so 5w and a postage stamp area with tremendous heat in a spot light or fully plastic bulb insulating the heat causing overheating

big-all wrote: ↑Tue Oct 06, 2020 11:02 pm as an aside
years ago lamp holders where brass and porcelain with a cloth shade so stone and metal brilliant for heat removal from the bulb so no overheating
as years progressed plastics come along so perhaps 20% replace as the porcelain bit turns plastic so a bit less heat removal
at the same time shades also turn to metal and glass so still cools as less airflow but plenty off heat sink ability
then you turn to a thin metal clip in the moulded now all plastic holder so give support to the bayonet pins in a glass lampshade so no real heat transfer as you have two power contact pins and the wire to take the heat away in an enclosed shade so lots off heat no heat sink and reduced airflow
you now have leds about 10% the power consumption for the same light with not even any volume off glass or metal so 5w and a postage stamp area with tremendous heat in a spot light or fully plastic bulb insulating the heat causing overheating

Are you suggesting that feeling the bulb and noticing how hot it is running should give me an indication of how likely it is to blow?

be very careful as they can get very hot but the cooler the better
but yes most failures tend to be heat related the bulbs used to have metal bodies as heat sinks but now most are all plastic to bring down cost

big-all wrote: ↑Wed Oct 07, 2020 5:36 pm be very careful as they can get very hot but the cooler the better
but yes most failures tend to be heat related the bulbs used to have metal bodies as heat sinks but now most are all plastic to bring down cost

Just had a feel. Scalding but not wickedly so.)hottest right on top)

What about this observation?

I have ,over the years put in lower wattage bulbs with the expectation that they would last a lot longer .Often this has not turned out to be the case and they have blown in a similar timeframe.

because they will have a lower ability to disperse heat because they are smaller
if you can remove the dome if one is fitted without touching any metal as long as out off reach from small [and big] hand then it will run cooler but must always be treated as a live danger whilst fitted even when switched off

Tungsten filament lamp life is very much dependant on quality of manufacture and design

As other have said heat is a major problem once full hot the temperature of the filament is very high and slight knocks will cause it to stretch , kink and as a result reduce the life of the filament especially if coils begin to touch and cause hot spots, they don’t like vibration either.

You used to be able to get rough service lamps which were more expensive and had more support of the filament.

Voltage will also have an effect , voltage can vary quite significantly depending on grid load , distance from transformers ect , in the city of London I have seen 3 phase go down to 385V during a weekday and up to 425v at weekends. With corresponding variations in single phase supplies.

I would have thought LED units with modern power supplies would not suffer from over voltage problems unless the actual power supply fails and not the lamp.

geordief wrote: ↑Tue Oct 06, 2020 6:16 pm Not sure what type ,but not the incandescent ones as I don't see them for sale anywhere and bulbs are now a lot more expensive than they used to be.

So I will guess some form of fluorescent, possibly 2D? With fluorescent voltage is really important, very low will not strike, bit low and it has to try multi-times to strike and it can take out the heaters, and too high and the current goes up with a logarithmic increase so a lamp designed to take 0.5 amp at 110 volt was taking 0.8 amp at 125 volt when I did tests.

That was in the days of wire wound ballasts, when we went to electronic ballast there was a huge change, a 58 watt fluorescent tube with a wire wound could take 56 - 70 watt depending on voltage but with electronic stable at 54 watt, it also removed the strobe effect, let them fire quicker, increased light output, extended tube life so in real terms fluorescent with a electronic ballast is about the same as LED but cheaper to buy.

What has happened with the old fluorescent is the fat tube has gone, so 5 foot 65 watt tube has gone, the 58 watt thin tube will fit, but the ballast does not really match, so instead of 4 year life I was finding lucky to get 6 months. Also with the advent of solar power, the supply voltage has dropped, as 254 is top limit at which solar panels will lock out, so the DNO has been dropping the voltage to 230 volt where when we first went from 240 to 230 volt in real terms nothing happened.

Picture of light would help. If my guess is correct, and since we do know what bulb it is, then likely either a new electronic ballast which likely means change whole lamp, or fit a LED conversion, problem with the LED they tend to be lower output, so for example a 58 watt fluorescent with electronic ballast will give out around 5400 lumen, but the LED replacement at 24 watt gives out 2200 lumen this is OK where the fluorescent lit a corridor where it was the length of tube which was important, but if you need 5400 lumen then clearly a problem using LED. The same applies with the 2D lamps, 28 watt fluorescent replaced with 12 watt LED dropping from around 2400 lumen to 1610 lumen a con really as people think they are saving money and the LED seems brighter until you try reading in the room, and then you realise less light.

But I am guessing, photo of bulb or lamp will help.