Multiple blown GU10s

[JohnW2]

Obviously you are well aware that voltage rating of lamps is quite critical to an incandescent lamps longevity?

Indeed I am (give or take the complication I mentioned in relation to halogens), since I wrote:

.... it is inevitable that, no matter what voltage they are designed for, any traditional incandescent bulb (and quite probably many LEDs) will have a longer life at 216.2V than at 130V, and a longer life with 230V than with 253V. Halogens are a bit more complicated, in that reducing voltage reduces the envelope temperature and hence may, in some situations, decrease life.

You go on to say ....

A 230v lamp, on an actual 240v supply will have a severally reduced working life.

... and, equally, a "250V lamp" or a "260V lamp" would have a markedly shorter life if supplied with 240V than if it were supplied with 230V, and a much shorter life than if it were supplied with 216.2V (previously mentioned possible caveats about halogens accepted).

Yet some sellers seem to not be aware, or care about this and sell 230v lamps intended for use in the EU.

You still haven't really answered my question as to what you mean by "a 230V lamp". Given the wide variation (around the nominal voltage) that exists in any country, I'm not sure what you are suggesting. There will always be considerable variation in life expectancy of bulbs across the range of permitted supply voltages, so there's not much a manufacturer can do other than manufacture bulbs to have a certain (average) life at the nominal voltage (and quote the 'average life expectancy' at that nominal voltage).

As I understand it, the nominal voltage in both UK and EU is 230V, the only difference being (to 'correspond with reality/history'!) that the asymmetrical permitted limits are asymmetrical in opposite directions in UK and EU - 230V -6% +10% in UK (216.2V - 253V) and 23)V -10% + 6% in EU (207V - 243.8V).

It is, of course (for reasons of history and reality!) the case that voltages in EU will tend to be appreciably lower in the EU than in the UK which means that the life expectancy of ANY bulb is going to be, on average, longer in the EU - but that may well almost fades into insignificance in comparison with the nearly 40V wide 'permitted range of variation in both UK and EU.

Kind Regards, John

 

[Harry Bloomfield]

You still haven't really answered my question as to what you mean by "a 230V lamp". Given the wide variation (around the nominal voltage) that exists in any country, I'm not sure what you are suggesting.

Despite Eric's suggestion that 230v is the UK standard and I obviously have not been round the country checking, but I would suggest we still do have a general 240v supply in most places. What I mean by a 230v lamp, is one stamped on the side 230v - one designed and manufactured for 230v, for best compromise of efficiency and working life. Other voltages are available, 10v Plus and minus - usually special order, but the standard UK voltage of lamp remains - 240v and no point me buying anything other than 240v, because within a volt or two, we have a 240v supply.

Actual supply voltage has become less important, now that so few incandescent lamps are in general use and modern electronics use SM PSU's.

 

[Harry Bloomfield]

230 volt is the nominal voltage, we all know range is 207 to 253, so all items marked 230 volt should be OK at 207 to 253 volt.

Except incandescent lamps! Which need to be fairly closely match the supply voltage.

 

[ericmark]

That only affects the lower voltage -5% for power, -3% for lighting, so not permitted to have as much volt drop.

 

[JohnW2]

Despite Eric's suggestion that 230v is the UK standard and I obviously have not been round the country checking, but I would suggest we still do have a general 240v supply in most places.

As I said, regardless of the confusing bureaucratic issue of 'nominal voltages', the actual supply voltages will, on average, be lower in most EU countries than in the UK - so, as I said, any bulb (that could tolerate the voltage concerned at all!) will, on average, last longer in the EU than in UK - but that's true whether is is called a '220V bulb', a '230V bulb', a '240V bulb' or even a '250V bulb'.

Don't forget that when the ('bureaucratic') 'nominal voltage' in the UK was closer to the UK reality, it was 240V ±6% (i.e. 225.6V - 254.4V) - so, although the average actual supply voltage was then fairly close to 'nominal', the range of 'permitted' supply voltages was not actually much different from what it is now.

What I mean by a 230v lamp, is one stamped on the side 230v - one designed and manufactured for 230v, for best compromise of efficiency and working life.

As I said, given that (no matter what the reality) the nominal voltage is 230V throughout the EU and UK, I would think that, strictly speaking, any bulb manufactured for, and sold in, any of those territories should really be be marked "230V" - although I realise that is not necessarily the case. In fact, it's obviously becoming increasingly difficult to buy incandescent bulbs with any marking, so the discussion is heading towards being rather moot.

LEDs are a different matter - whilst the life of the cheapest ones (with just a capacitor or two and rectifier) may well be fairly voltage-dependent, the life expectancy of those with more 'sophisticated' current control may well (as you go on to say) not be very dependent upon voltage - I don't really know for sure.

Kind Regards, John

 

[ericmark]

The LED R7s lamp I used for my outside lamp was marked 85 to 250 volt, I have the boxes for two smart GU10 bulbs, one no voltage marking the other the box for non smart GU10 also said 220-240 50/60 Hz. Old quartz GU10 240 volt, 50 watt, 350 lumen 2800K Germany Tesco written on the bulb, and the old Pro-Lite GU10 7W FLU 2700K 220-240V ~50/60 Hz 50 mA so all my GU10's are designed for 240 volt. With the energy saving types a range 220 - 240, and the quartz 240 volt.

A lidi E27 Smart bulb was marked 230 volt 50 Hz, but the still boxed B22d bulb tungsten marked 220 - 240 volt. was surprised the pearl bulb 40W 380 lumen, the clear 40W 350 lumen, I had not realised how much worse the GU10 was compared with standard bulb I thought quartz was better not worse to standard bulb.

But two 11 watt CFL one marked 600 lumen the other 700 lumen. Both still new and boxed, really should dump them.