If L.E.D. lights rated at 220 Volts are supplied at 240 Volts will they perhaps flash on and off?

LED lights for both Germany and the UK should be rated 230 V.

Table 1 of BS EN 60038 CENELEC Standard Voltages. Manufacturers are pointed in Clause 4.1 of the standard, to the fact that the supply voltage (at the origin of the consumer's installation) will have a variation within ± 10 % (in the UK, according to ESQCR, it's + 10 %, - 6 %), and that there will be a further voltage drop within the consumer's installation according to HD 60364-5-52 (Chapter 52 of BS 7671 in the UK).

In fact, 220 V is not an IEC standard voltage either (IEC 60038) ... for 50 Hz supplies, it's still 230 V, which means that the lights are not produced for a country that follows IEC standards either.

So I would either not install them, or query the voltage with the manufacturer.

The standard voltages have been that way for some very very long time.

The decorative L.E.D. ceiling lights were supplied by the customer and the box rates them at 220 Volts. I queried this with the customer but was still asked to fit them. Their flat is in a new build so the supply Voltage may be high.

Z.

Perhaps, as I had a similar problem to this with some dimmable Osram/ LEDvance LED filament lamps - actually they would run, but only for about 15 mins, then start to flicker and got very hot at the base with the electronics - which said thermal overload to me. As they were mine at home a bit of experimenting was in order, and I found  they will stay on either with a conical sheet aluminium heatsink clamped to the outer of the B22 base, looking rather  like those collars that vets give to poorly dogs to turn them into a megaphone, or more practically with couple of hundred ohms in series (suiatable rated - no miniature parts on mains please !) to dump 20volts or so, which I have hidden in the base of the fitting. So far several thousand hours later, with the resistor mod, running cool and still going strong. Whe one fails I will crack it open and see what is within, but being tight fisted I do not want to do that to a working one.

Neither of those ideas would be a good solution for customer equipment, but it does suggest that at least one reputable make does not run long term tests  over the full 207-253 volts that they really should for CE marking . Perhaps other makers also do not.

Mike

Strange this. But I have a number of led lamps that gradually start doing this flashing on and off after a few hundred hours of use. They have ES caps although marked 230V, and I have a bc cap one with the same problem marked 240V. Very curious, no diagnosis yet!

I had a couple of Philips pseudo-bulbs which failed. The first stage was that the columns of LEDs were dancing round and round.

I have opened up some non-dimmable led lamps that are just a series capacitor and then a bridge rectifier and long  string of perhaps 100 diodes totalling 150V or so. These are very sensitive to supply voltage, as the LED has a very sharp (near exponential) turn-on above a threshold of 1.5 volts or so per chip.

I have also seen some with a simple linear regulator in series with the diodes to give a degree  of constant current, but the heat dissipation in the regulator part  is then highly dependant on the difference between the rectified mains and the voltage across the LED chain. We know that the lifetime of the LEDs and any linear regulator will be critically dependant on temperature, so perhaps it is not such a surprise that over voltage causes problems.

At best the flashing may be an automatic thermal shut down  of a regulator, or more finally  it may be the LED die coming away from the metal part of its body that serves as both a contact and heatsink.  You need surprisingly few tens of milliwatts to raise a cubic mm of semiconductor to a failure temperature, once it is not well connected to the outside world in a thermal sense.

As I said earlier, I do not know what is in the dimmable ones, but when one fails I'll come back and report assuming I can find the thread again.

Mike

It may not be entirely coincidental that the mains voltage in China is 220V.

It may not be entirely coincidental that the mains voltage in China is 220V.

Officially 220V, and 380V phase to phase  - not always in practice - but if out of bounds,  usually on the low side rather than high.  I have heard it suggested that when a lot of this was being set-up, there was a desire to be compatible with the Soviet bloc  in terms of voltage and wiring practice, though this never extended to the sockets, which are more like the type you see in Oz or Nz.

Mike

mapj1 said:

At best the flashing may be an automatic thermal shut down  of a regulator

Ooh, I think that I may have found out how to quote.

Mine was not flashing randomly - the columns were flashing in turn, so the result was a rotating beam. Quite apt on the coast!