When the declared voltage changed from 240 to 230 to harmonise there was in real terms no change, however micro generation has changed that, because the micro generators have to close down with over or under voltage the tapping have been now changed in many areas, and we are now getting around 230 volt average rather than 240 volt average, and as a result fluorescent fittings that have worked for years are failing.
I was given the task to fit temporary light on a large building site, and the boss had decided using fluorescent lights would be a better option than the standard 60W bulbs. The fittings we 110 volt 5 foot so quick calculation 58W would mean two fittings would use just over an amp, so 16A supply should supply around 32 fittings, but to give some leeway would use 25 fittings.
However called to look at lighting which had tripped, clamp-on meter showed using around 20 amp, so set out to find out why.
The fitting had a standard 230 volt ballast and starter, plus an auto transformer to step up voltage marked 110-0-127 volt, it was found if the supply went to the 127 volt tapping the current dropped from around 0.8A to around 0.6A so total dropped to 15A, however last few tubes failed to light, so first 20 changed, last 5 left at 110 volt tapping. And they then worked fine.
However these tests showed me the problem with magnetic ballasts in fluorescent lights, voltage is critical, too low and they fail, too high and they use well over rated current. Then came the electronic HF ballast, it has a high voltage range, so a 58W fluorescent actually uses more like 56W, and the high frequency (HF) means reduced strobe effect, it puts less strain on the tubes so they last longer, and actually the light output is increased, all round they are an improvement on the old magnetic ballast. In fact I don't think it is permitted to supply fluorescents with magnetic ballasts any more.
However when comparing LED with fluorescent it is compared to fittings with a magnetic ballast, so all the statements as to savings are false.
A LED package typically gives 70 to 110 lumen per watt, the lower outputs are in the main bulbs designed to be able to dim, using switch mode or pulse width modulated drivers they produce between 95 to 110 lumen per watt, the first LED tube I fitted was 24 watt and 2400 lumen so 100 lumen per watt, the second was 24 watt and 2200 lumen so 92 lumen per watt.
The fluorescent tube not so easy, it states 58W and 5200 lumen around 90 lumen per watt, but the HF ballast is claimed to increase that output and decrease power used, so in real terms output for fluorescent and LED very similar. The main gain is you are using a lower output lamp, you are using half the power, but also getting half the light.
With the compact fluorescent the 11W lamp was rated at around 64 lumen with LED at around 75 lumen how ever in both cases the light was radiated in a different direction to a tungsten 60W bulb so when the tungsten was replaced we often in real terms got less usable light, once light is absorbed by items in the room it becomes heat, we all know white curtains are best, as is a white ceiling, floor etc. However they don't look good, so we use other colours which don't reflect all the light, so putting a bulb with base at bottom or base at top in real terms affects the usable light. It may be 75 lumen but it does not light the room as well.
I replaced 10 Philips globe CFL 8W each with 10 Lidi candle LED lamps at 3W each and the room appeared brighter, however when trying to read a book found I needed a table lamp, so then fitted 10 Home bargains 5W globe lamps and I could again read without a table lamp.
