Bulb blowing

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Indeed. In fact, as we've often discussed, a 13A BS1362 fuse will support something like 22A continuously and indefinitely without blowing - so rather more than "quite a while" :)

The 13amp fuse might, but the hardware around it (plug and its fittings) would show signs of early distress.
 
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The 13amp fuse might, but the hardware around it (plug and its fittings) would show signs of early distress.
Yes, very probably, but we were talking about what it takes to blow a fuse - and, as I suppose your comment illustrates, a 13A BS1362 fuse may well (in overload situations, not 'fault' ones) allow a high enough current to flow for long enough to damage other things.

Kind Regards, John
 
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The incandescent light bulb can be long lasting however the light output at 1/10th of design is not really going to light much, and when I used tungsten rather than carbon filament bulbs I would change one around every 2 weeks, not the same one, but around 16 bulbs in regular use, so around 6 mouths per bulb.

When using fuses the ionisation (bright flash when bulb blows) did not take out the re-wire-able fuse, there was suppose to be a fuse built into the bulb which should rupture first, but this was when bulbs made in the UK, I found some imported bulbs did not have this fuse when one from Ikea welded its self to the contacts on failing, not helped since using a 16 amp MCB on that bulb, the 6 amp MCB would trip before any bulbs welded them selves to holder, but the solder contacts would often misshape forming a dint in centre which would make removal a problem in some cases.

Although the supply was originally rated at 240 volt, it was always on the high side, more like 250 volt, even when officially it dropped to 230 volt with harmonisation the real voltage did not change until solar panels were fitted so some homes in the area when the voltage did drop, seems solar panels must auto disconnect if voltage not in the 207 - 253 volt range, so likely complaints that they kept auto disconnecting.

The compact fluorescent bulb (CFL) was claimed to last longer, however when I fitted 16 after just one years I was replacing bulbs, and even with LED had a fluorescent tube replacement last less than 18 months, one odd bulb went within a day, although latter fixed, opened to see what was inside the bulb and found a dry joint and a smart bulb failed within a few month, they are rather complex, 20220603_113849_1.jpg so like any bit of electronic equipment you will get the odd one fail, but in the main LED lamps last for years, although my son seems to have had a bad batch, although he does not have a surge protection device (SPD) fitted, so not sure if failed due to surge or poor bulbs.

I have had bulbs go dim, not quite as bad as the centennial light, but both CFL and LED seem to have reduced output, I will continue using tungsten bulbs in the oven, and a table light with built in dimmer, but in the main when a tungsten fails it is replaced with LED.

Before the quartz bulb I did fit dimming switches which seemed to extend bulb life, however ionisation could take out a dimming switch, so swings and roundabouts really, and with quartz you should not dim the bulb as it shortens the life, so when the CFL arrived any dimmers were removed, and when the LED arrived easier and simpler to use smart bulbs, removed the problem matching electronic switch with lamp.

I have last more electronic switches than lamps, of 5 smart switches now down to 2, used with remote controls for bedroom lights so we and switch on/off in bed, but more bulbs changed because they flash or flicker with smart switches then changed because they have failed.

The problem today is more having a draw full of new bulbs due to old stock of tungsten, or swapping LED as too bright or dim for location, or flickered with electronic switch, not helped when tungsten bulbs came as packs of 10. Still loads of CFL sent to parents by electric supply companies to encourage them to use energy saving, all BA22d and there are so few fittings still using that base they will last for years. Seems I now have mainly E14 or SES base bulbs.

Good job bulbs last longer, as very few rooms with less than 4 bulbs, living room ceiling light has 8 bulbs, this is in the main due to LED lamps being in the main directional, a single 100 watt tungsten bulb had just a small area where the base was where there was no light, replace with LED, as first problem is 100 watt tungsten is around 1000 lumen, it may be claimed a 15 watt LED gives same light, but in real terms needs around 20 watt plus, and the second is all the light being directed to a dark floor does not really give same spread as when reflected off a white ceiling.

So moving tungsten to LED has resulted in changing light fittings so we can get the extra light, with 3 to 8 bulbs per fitting, this also means one wants the bulbs in the main to match, OK I do have one where centre bulb is different to outers by design.

Bulb blowing is likely more of a problem today as we have G9, G10, E14, E27, BA22d, and other bulbs, where years ago all were BA22d, and they last so long we will once existing stock is gone, likely not keep replacements in stock, but only buy as and when the blow.

Main problem is disposal, we should not put LED bulbs into general waste, however to travel 16 miles to dispose of the bulb is silly, I have seen boxes for batteries in shops, but not bulbs, I know they should take them for recycling, but last time I took a fluorescent tube to Wickes for disposal when getting a new tube they refused, so it sat outside house until wind knocked it over and is smashed, at which point it was swept up and put in general waste, may as well have put it there to start with then mercury would not have gone into my garden. I note bulbs from Lidi have the 1655791348127.png symbol not 1655791433215.png but seems it only means do not litter, not it can be put in the bin.
 
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The problem today is more having a draw full of new bulbs due to old stock of tungsten, or swapping LED as too bright or dim for location, or flickered with electronic switch, not helped when tungsten bulbs came as packs of 10. Still loads of CFL sent to parents by electric supply companies to encourage them to use energy saving, all BA22d and there are so few fittings still using that base they will last for years. Seems I now have mainly E14 or SES base bulbs.

I too have a stock of old tungsten lamps. As I gradually swapped them for LED, I kept the removed lamps as back ups - I needn't have bothered, I have not had a single LED fail since I began replacing. I was having a bit of a tidy up in my garage and workshop, found a couple on a shelf in there, so those were the first to hit the bin, along with a couple of 500w halogen PIR fittings. One of which I had fitted a peculiar linear CFL to, intended to replace a 200/500w linear halogen lamp I had picked up from somewhere.
 
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Obviously not literally infinite, but it could be very high (and very brief), possibly high enough to blow a 13A fuse (or even a higher rated one, if such was available).

As Harry has implied, the duration of very high currents when a bulb blows is often too short to blow a fuse, whereas much more common to triop an MCB, but even fuses sometimes do blow in that situation.

Kind Regards, John
It's my first ever bulb blowing taking out a fuse. Hence I am completely unfamiliar with the situation. I will see how well the LED does. The 12W LED is brighter than the 40W incandescent and an excellent replacement.
 
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The compact fluorescent bulb (CFL) was claimed to last longer, however when I fitted 16 after just one years I was replacing bulbs...
early CFLs were made before makers had much experience of life. I got a few (rather expensive) large globe lamps for use in exposed shades, some by a brand using a name similar to a well known maker failed very fast

but I put a Philips stick CFL in a high fitting in the hall, so I wanted long life. When it started flickering in 2020 I got out the tall stepladder and changed it, glanced at the base where I had written installation date, and thought it had lasted five years, which seemed reasonable.

when I was taking it to recycling I looked at the base again, and saw that it was not 2015, but 2005.
 
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We had one odd light at work, due to being odd one out, a 500 watt son, it was very easy to see how long it lasted, and it seems between 5 and 10 years between each bulb change. However it seems life of a bulb is worked out by how long before 50% of the sample fail, not sure what sample size has to be, but when using fluorescent we would change all tubes failed or not when 25% had failed, so 50% seems to me too many.

There are devices to lower and raise the voltage to lighting to try and in the main reduce energy used, as fluorescent lamps with magnetic ballasts are not linear with power use v voltage, however in the main magnetic ballasts and tungsten lamps have been phased out, the few tungsten that are used are normally specials being able to stand the heat of an oven etc, so not worth using any power reducing units.

LED's are a problem, the driver can be rather complex, but it can also be rather simple, a capacitor for example, where the voltage is shown at for example 150 - 250 volts one can be reasonable sure using a pulse width modulated controller, and also where it incorporates some smart feature, but as to how likely they are to flash when switched off due to capacitive or inductive coupling or powering a smart switch, or how likely to flicker when on, it is suck it and see.

Flicker is a problem when anyone is sensitive to light caused seizures etc. I can fit lights which are OK for wife and me, but visitors find a problem. Also there is the strobe effect, until one sees what you know is fast moving seem to be moving slowly or stopped, one can be unaware the bulb fitted can cause a strobe effect. We should display signs 1655811024836.png but unless the bulb has a warning how does one know if signs need displaying?
 
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However it seems life of a bulb is worked out by how long before 50% of the sample fail, not sure what sample size has to be, but when using fluorescent we would change all tubes failed or not when 25% had failed, so 50% seems to me too many.

Light output of florescent can reduce as they age. Some companies work on a regular tube replacement regime, especially where access to change odd failed tubes is difficult, needing special access equipment, or shutdowns.
 
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Light output of florescent can reduce as they age. Some companies work on a regular tube replacement regime, especially where access to change odd failed tubes is difficult, needing special access equipment, or shutdowns.
This is the problem, if I am to use lamps rated at say 10,000 hours and they are used 24/7 then after one year should need 50% changing, so with a Christmas shut down and summer holiday shut down should be able to do two changes per year.

If 20,000 hours only need changing once a year this assumes takes twice as long for 50% to blow than for 25% and want changing when 25% have failed. At 50,000 Hours Lifetime for a 5 foot 22 watt tube looking at 5.7 years at 50% which begs the question why a 3 year warranty?

If only used 50% of the time then looking at 11.4 years, and for evening only we are looking at 20+ years life, so why 3 year warranty? What seems odd was a tube has 50,000 hours life, but a disposable fitting 30,000 hours, yet the warranty was 5 years (43,800 hours) not 3?

What I have not seen as yet is need to show a SPD is fitted to claim from warranty. Or proof not in use 24/7.
 
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13A BS1362 fuse will support something like 22A continuously and indefinitely without blowing - so rather more than "quite a while" :)
Really ?

I believe that I had been "taught" that a normal "fuse" would carry its rated current indefinitely but would "Bolow/Rupture/Operate/Disconnect" within 30 seconds of carrying twice its rated current.
Hence. a 70% overload, such as described, should cause the fuse to "operate" at sometime short of eternity - even if more than 30 seconds !
 
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Indeed. In fact, as we've often discussed, a 13A BS1362 fuse will support something like 22A continuously and indefinitely without blowing - so rather more than "quite a while" :)
Really ?
Yes, really ...

1655821116851.png

I believe that I had been "taught" that a normal "fuse" would carry its rated current indefinitely but would "Bolow/Rupture/Operate/Disconnect" within 30 seconds of carrying twice its rated current.
I'm not so sure about that "30 seconds" - are you sure you don't mean 30 minutes? The 'fusing factor' of a 'normal fuse' has, indeed, always been taken as 2.0 (i.e. relating double the rated current), just as the 'fusing factor' of an MCB is taken as 1.45 (i.e. relating to 45% over rated current), but the later relates to operation of the MCB within 1 hour at 1.45 x In - so I would suspect that the 2.0 figure (2 x In) fuses is similar (operation within 60 minutes - or, perhaps, within 30 minutes).
Hence. a 70% overload, such as described, should cause the fuse to "operate" at sometime short of eternity - even if more than 30 seconds !
See above curves and the text above.

Kind Regards, John
 

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