Lights blowing

[meg_mog]

Hi there,

I'm a newbie so hi there! Apologies if this is a stupid query but I'm doing my nut having to replace bulbs on an almost weekly basis (and I have searched previous posts too but still need some advice..).

We moved in about 2 years ago, the house was supposed to have been re- wired (at least partially) within the last 5 years, all the lights are on one circuit and we have modern switch type fuse box (sorry not a tech, just giving my best description..).

At first with standard bulbs they were blowing one every couple of weeks, in addition the kitchen light (flourescent tube) had a flickery effect when coming on and was prone to tripping the circuit.

First we replaced all our standard bulbs with energy efficient ones. No help, it just became much more expensive to replace them. The kitchen light was quite old and also our son flooded the bathroom (directly above the kitchen) with the effect that everything got soaked and we thought maybe that had affected something in the light fitting. Scrapping the whole light fitting we bought a nice bright halogen track light from IKEA.

Sometime over the last couple of months the rest of our lights seem to have settled down and I haven't had to replace one for ages. The flip side of this is that the halogens have been a disaster, there are 5 x GU10 35 watt bulbs on the track and they blow at a rate of 1 or 2 a week....

In terms of contributing factors, they are not recessed, not anymore exposed to heat/vapour than would be normal as it is a fair sized kitchen with extractor, there has been once since we got them another 'flood' from above (courtesy of my son - AGAIN) but they were already blowing before this happened and I just don't know what is wrong or how to find out (short of calling an electrician which seems a little excessive...)

Any suggestions on what is wrong and how to remedy it would be very gratefully received :)

thanks for reading, fay

[Dave Liquorice]

That tale sounds very much like the supply voltage being on the high side. If you feel confident about measuring the mains voltage go ahead, otherwise contact your local distribution company (this may or may not be the same company that you pay for power). They should come round and measure the voltage and if in tolerance fit a recording volt meter to see how it changess during the day.

The main should be a nominal 230v but the allowable toerance means it can be as high as 253v or down to 216. I'd expect it to be 240v +/-5v.

[robgraham]

Hi Fay I think Dave's suggestion is quite likely.

But could you help us by telling us what sort of house you've got and what sort of situation it is in. For instance are you in a housing estate and does everyone have/have not the same problem ? Or are you out in the sticks with an overhead line distribution ?

I would like to think it is the latter as it would suggest that the tapping on your local distribution transformer is set too high.

Rob

[The Natural Philosopher]

Do what I do/did.

Replace all mains halogens with LVS. These last years, not days.

Get the halogens from Newey and ~Eyres - newlec brand. They last and are half to one quarter the price.

Go to ebay and look for bulbs. I buy in 50's. Never buy supermarket bulbs except in an emergency. They are 4-10 times te price and blow instantly..if they work when you plug them in, at all.

Its all part oft a grand plot to make us buy CFLS, which fail just as often ;-)

[meg_mog]

Cheers Dave. I'm about to betray my utter ignorance in matters electrical by asking an exceedingly dumb question.... I know the voltage for the socket circuit as we've just bought a little plug in appliance energy meter as another problem we have is strangely high electricity usage (for a small house with gas C/H and cooker) and the voltage reading from that is a pretty steady 250.5 v - is that likely to be accurate for the house mains supply as a whole...?

Rob - We live in the middle of the city in a brick built terrace circa

1900, I don't know of any neighbours with the same problems....

So,

-is the 250.5v measurement likely to be reliable?

-if it is and supply voltage is on the high side, is there anything to be done..?

-does it have any other effects...?

-given none of neighbours have the same thing could it be something else..?

cheers,

Fay

[meg_mog]

Advice gratefully received but you are dealing with an ignoramus here, what are LVS's....?

They need to be, the cost of all the bulbs we are going though atm.. ;)

Ebay, hmmm, had never occurred to me to buy bulbs like that...they ok in the post?

Oh dear, another dunce moment, what are CFLS's...? (are these the energy saving ones that are touted as the best thing since sliced bread...?). I have to agree that even before we lived here our energy saving lightbulbs never lived up the manufacturers 15 year claims although I could never be bothered to complain - what ever tests they run must be rigged me thinks!

[John Rumm]

It could be - depending on the quoted accuracy of your plug in meter. If it is correct, then that does indicate a voltage on the high side.

You would need to get in touch with your supply company and tell them you think your voltage is too high.

It means that things will run at higher powers than the rating plate would suggest. For example if you had a kettle designed for 3kW output at 230V, you would in fact be getting over 3.2kW. Most appliances will be designed to cope with voltage variations however without too much problem. Filament lamps however are quite sensitive to it.

One possibility worth checking is if you have any light switches that are particularly "noisy" electrically (old dirty switch contacts etc) - these can affect the bulbs, especially the GU10s it seems. I had a case with an elderly neighbour once who would call me round to change her hall light ever week or two. After several bulb replacements I also changed the light switch in the room. After that the problem went away.

Other things to check: GU10s are particularly poor in coping with any vibration - i.e. from the floor above. Buying quality bulbs usually costs less in the long run.

[John Rumm]

Low Voltage halogens. These run at 12V and not mains (hence they require a small transformer to step down the mains voltage). There are many reasons why they are superior:

> Its all part oft a grand plot to make us buy CFLS, which fail just as >> often ;-)

Compact Fluorescents.

may find some helpful information here:

[The Natural Philosopher]

Its an ebay shop I used.

Distributes to the whole nation by courier.

Yes, they all made it. Unlike supermarket bulbs.

Compact Fluorescent Lights

I have to agree that even before we lived here our energy

[The Natural Philosopher]

Low Voltage.

Get transformers and install 12v stuff. Mine typically last over 18 months

Both people I know who have had mains halogens in have hated them simply because they blow ALL the time and are a bugger to replace.

I pay around 55p for a 50W 12V halogen bulb: a 240v one is around £4 in the supermarket..my transformers were around £7.50 and the fittings around £2.50. Go figure payback period.

[The Medway Handyman]

AAMOI whats the tolerance for mains voltage. ISTR 230v + 10% - 6% ?

[John Rumm]

Yup that is the official line - so 253 to 216. However you can sometimes get them to change something if you are close to the limits.

[meg_mog]

Thank you for the comprehensiveness of your suggestions, I'm off to find the information sheet about the elecky meter to find out its quoted accuracy (I do remember reading it I just can't remember the figure). I think that fitting a transformer and replacing the GU10's will have to wait until after Christmas but since the rest of the lights in the house seem to be ok at the moment and we haven't had one blow for a couple of months I will start with trying replacing the switches and switching to LVS's in the kitchen before getting bogged down talking to the electricity company about high mains supply voltage.

thanks again and happy Christmas,

Fay

[John Rumm]

Note that if you have single downlighter type fittings, you can get small transformers that aare small enough to fit through the hole for the light. Hence you can swap a mains downlighter for a 12V quite easily without any disruption using one small transformer per fitting rather than a larger one powering several.

And you!

[robgraham]

Bulb sensitivity to voltage is something like V to power 13 IIRC, Even if it isn't as big a number as 13, it's somewhere in that region.

On the subject of GU10's, my recommendation to anyone using them is to ditch them and their holders and switch to a 12V equivalent. GU10's have a shocking reliability. OK a 12v system requires a transformer but the modern electronic ones bring up the supply without a surge so that the bulb filaments are protected. The other advantage of the 12v systems is that if the bulb fails it doesn't trip the MCB as a side effect.

Rob

[Dave Liquorice]

Modern stuff normally has pretty good accuracy, I'd expect 0.1% and +/- 1 on the LSD. Even at 1% thats only 2.5V error.

Even with a 1% error it's certainly a case for contacting the board. Even out here in the sticks with no heavy industry the voltage range min to max over a 24hr period is not far short of 10V.

This is what I would do, in fact what I did do when I purchased a UPS and the thing when straight into "voltage reduction mode" when I plugged it in!

The supply was up at the top end of 240 with peaks to just over the upper tolerance of 253V (data polled from UPS and plotted). Incandescent light bulbs weren't lasting very long. Rang 'em up, man was at the door inside two hours (he lives in the town) measured the voltage, agreed it was high and inside a week they came back and adjusted the tapping on our transformer down as low as it would go and we now sit at 240V with slightly less than +/-5V over the day variation. Incandescent light bulb failure is now *much* reduced.

It might not be quite so easy in an urban enviroment as your supply will be feeding quite a number of homes. It's a common problem that those near the substation have an upper limit voltage supply, those at the far end a lower limit supply. You can't just lower the voltage or the far end people fall out of tolerance.

It would be worth asking neighbours how often they change bulbs, most ordinary incandescent bulbs have a quoted life of 2,000hrs. In very rough terms this means replacing a bulb that is on for 5hrs/day every day once in 13 months or so. 5hrs/day is probably longer than a hall or landing light left on every evening.

[The Medway Handyman]

Interesting that Dave. I live in a cul de sac at number 20, there is a sub station at the end of the road some 10 house away. However our cul de sac is in the middle of a large circular estate, shaped like a capital letter 'Q'.

We do get through light bilbs at a rate of knots, voltage is regularly at

248v +. From what you say, if they turned down the upper limit we would be better off, but what about the rest of the estate? Would a lower voltage cause them any problems?

[Andrew Gabriel]

Your lamps would have been giving off about 20% more light for

10% more power consumption and 50% life reduction.

1000hrs actually. (750hrs for vacuum bulbs.) 2000hrs is a lower efficiency double-life lamp.

[Mike Clarke]

Unless it's one of the cheap 'n cheerful plug in power meters. The Workzone one from Aldi only claims +/- 3%, that's 7 volts either side of 240V.

[meg_mog]

Btw, meant to ask earlier, is there any advice on where I can get the various things suggested - LVS bulbs and 12 V transformers needed at a reasonable price, please...?

fay