Replacing light bulbs with LEDs - LED lightbulb information

JimmyMac

any recommends for bathroom bulbs? I currently have energy saving standard edison screw bulbs in there. I guess it would need to be a candle style bulb as the bulb points parrallel with the ceiling rather than downwards so it needs to direct light all around. Both rooms are a bit dim at the moment and could do with being a bit brighter, the ensuite is fairly small so doubt it needs anything too powerful

x3j3UKN

My kitchen has 6 50W Halogen spots in and I have been slowly working my way through the spares ive had.

two have gone this week & as I no longer have any spares to chuck in ive decided to replace all 6 with Astralumen 5W GU10 LED. According to my calculations i'll save around £80 per year based on around 6 hours usage per day.

I'll use the 4 other spots remaining as spares for the bathroom and will replace these with LED's once ive worked through the spares left.

Cliff

I recently bought some small 3 watt G9 and candle type E14 LED lights.
Now, I found that one was not working so I had a look inside.
I was a little shocked to discover that the cheap LED lamps have a very simple dropper capacitor.
This is not energy efficient at all! If you studied electrical power at school, then you may recall that watts are calculated by multiplying volts x amps. That is fine if the load is resistive (power factor 1).

Now if you and the rest of your village uses LEDs with a capacitive dropper then the load to the generating system will be much higher than the watts.

This is why... and you may have wondered.. why generating sets are not rated in kilowatts but KVA. (kilo volts x amps)

Example: total house LEDs = 230watts = 1 amp drawn. wrong! It will be more using a capacitor. It could be 230 watts but 500 VA! loading the power station and taking double the power.

Moral of story. Look for a well known brand that use an electronic switching dropper inside the lamp housing which will have a power factor of 1.

MartinPickering

I've never understood this Power Factor concept. If the capacitor dropper is taking more power, where is that power being dissipated?

Cliff

It will be dissipated as extra heat on the grid.
This is because if you look at a 50Hz sine wave of current drawn and at the same time display the voltage waveform they will not be in phase. Note, unlike a resistor the capacitor does not get hot!

Your electric meter will register 3 watts being drawn and that's what you pay for, but the electric company will be supplying greater currents!

In fact if you run a small manufacturing plant you have to maintain a reasonable power factor- or you could be in trouble.
If you have capacitive loads and inductive loads- say fluorescent tubes and induction motors then these will counteract each other and bring the PF back in line. (Ideal is a resistive load)

MartinPickering

OK, thanks. This is interesting.
Is your "sign wave" the same as a sine wave (as in "sinusoidal")?
Could one add an inductor to the LED light to correct the problem?
And, finally, do you know if the "electronic switching dropper" is fully screened and filtered so it doesn't radiate significant interference or feed it back up the mains supply?

Cliff

Spelling corrected

I think you could add an inductor, but to be effective at 50Hz it would be bulky and not fit inside a G9!
Anyway, if we are considering an inductor, you might as well use a mains transformer and rectifier

As for screening, well I guess that is up the manufacturer. The cheap ones I have seen are not screened.

It is also good practice to put in some mains filtering- inductors capacitors and ferrite beads to reduce RF being fed back to the mains. But I am sure these optional components go when the price is low.

MartinPickering

That explains why so many people are having interference problems with so-called "energy-saver" lights. I guess you get what you pay for. Pity there isn't an ISO standard for them.

Zebedeeboy

Hi

I'm trying to sort out a replacement for incandescent R80 downlights in a kitchen,. I don't want to get into replacing the fittings (E27) at the moment just source a reliable LED replacement. The price is less important than the service length (£8 bulbs that blow every month aren't a saving over a £30 bulb that will last two years). Reviews on Amazon were pretty scathing about Megaman

Does anyone one have any recommendations based on their experience?

Confucius

Can't comment on R80s, but I've got some R63s upstairs (bathroom, bedrooms & shower room) and some R50s in the kitchen.

2 of the R63s are Megaman (7.5W, 2700K) and are a good match for the (60W) incandescent originals, in both colour temperature and lumens - in fact they seem brighter if anything.

2 of the R63s were from Homebase, 'TCP' being the make. The other R63s and R50s are Prolite. Both TCP and Prolite are 'cooler' at circa 3000K colour temperature.

The Prolite and Megaman bulbs were from Lamp Specs (Light Bulbs & Tubes. LED Lamps. Energy Saving Lights & Light Fittings.)

Couldn't see reviews of Megaman's R80 LED on Amazon, only the (discontinued) CFL.

About to order a couple of 5' LED flourescent tube replacements, which will complete my home's 'conversion' to LED lighting - all 41 bulbs (including the fridge light), apart from the oven lamp and outside security lamp* - for which R7s are not yet bright enough in my opinion.

*One can get LED security lamps for around £70 that out put ~4500 lumen, I might replace the current one in the Autumn when it starts getting activated more often.