Replacing light bulbs with LEDs - LED lightbulb information

inkinoo

Must admit I'm quite enjoying it

Cliff

If anyone is interested in what goes inside an LED light there are a number of tear down videos on You Tube.

This one made by Cree has quality electronics, small switch mode PS and PF correction.
                               
This one has a simple capacitor dropper .

grahamlthompson

That's what I was trying to do.  I did not want this misguided and inaccurate information to stop anyone replacing incandescent bulbs with leds that in some weird idea would cause problems for National Grid. It will not, quite the opposite.  Just because you do not understand the position does not make this important information.

If everyone connected to the same local substation replaced there incandescent bulbs with the same wattage as installed with led bulbs totalling the same wattage then yes  the current required from the local transformer and carried by the cables from the transformer to your property would have to carry more current.  That could cause the local transformer and perhaps rather larger cables to be installed by whoever is responsible for the low voltage network.  The whole idea is ludicrous, a 5W or so LED bulb produces as much light as a 60W conventional bulb. If the PF of every bulb used was the poorest design that would make the current equivalent to a 10W conventional bulb.  Any one replacing said bulbs would have to install lights delivering at least 6 times as much light as the ones being replaced.  Surely you agree that is not a realistic situation ?

You may struggle to understand this but :

National Grid estimates the demand 24/7 (this includes the inherent system losses). For the UK system that is just 1.6% of the total transmitted power.   They instruct the output of all power stations to output this power to meet the demand.  They also allocate reserve power which is capable of increasing power output very rapidly in the event of the demand increasing, and more importantly to cover the loss of generation or transmission line faults (A combination of part loading the most expensive conventional generation and rapid response generation sources like pumped storage and gas turbine plant). Any extra current (which there will not be), will be minute in terms of the national system.

The system itself has limits on where you can use the required generation, because of where it is located related to the connected demand. In this case you have transmission limits, that will cause more expensive generation to run to secure the system against fault outages.

He had the weird idea that generators are rated in Volt Amps, being the sole input source of real power they are rated in watts.  It's the connections from the generators to you, overhead lines, cables and transformers that are rated in VA terms.

Cliff

Well I agree with most of your last post.

I checked one of my original posts and made small correction where I saw inaccuracies.

As Graham says, it won't make a lot of difference,  and LEDs are a minuscule load.  He is used to national grid solutions and I am more used to power plants so we do tend to come from different corners when it comes to watts and kva. The National grid compensates for PF so power is not lost except over the distribution.
I won't say any more....

To get back to my original 'LED' post from a year ago, when buying LEDs, it is preferably to have an electronic reducer rather than a capacitor. My YouTube post 142 shows examples of both types. Typically a 'good' brand will have the electronic solution and the cheap ebay LED will have the capacitor. It might be small, and I agree, that compared with an incandescence, any LED solutions better.

I'll leave it at that.

Minty

Just to say some of the most enlightening comments I have read on a forum for many a year. Many thanks gentleman.

M

Glenn Uk

And all I wanted to know was can I find G9 replacement LEDs that are dimmable and came across this thread, wonders of google eh.

Norrie45

All very interesting.  Could anyone help with my request of 8 November please?

"I bought two Philips MR16 10w leds to replace 50w bulbs in my kitchen. They worked fine, so I bought 10 more. They do not work in any of the sockets, but the original two work in several sockets. The 12 bulbs are all the same specification. These bulbs are supposed to work with all transformers. Help please."

grahamlthompson

The 240/12V transformers used have a minimum load before they work.  10W is larger than is normally required to get the equivalent lumen output to 50W halogen.  Can you pull down the transformers through the hall in the ceiling to access the mains connections ?  If so convert to GU10 fittings.


Lampholder GU10 240V 50W with Clamp - Toolstation

I had to fit a constant current driver to make 3 2W LED 12V bulbs work in a cooker hood (replacing 3 20W halogen bulbs).

nonumb

Just a quick note. Just had some megaman Incanda-LED dimmable bulbs delivered and they are fantastic.

Dim right down with no noise and an exceptionally warm light even with my fussy lightwave rf dimmers.

Norrie45

Unfortunately the transformers are neatly packed above a false ceiling so are not readily accessible. I want to get away from 50W to an LED so maybe a constant current driver is the answer.  Any suggestions as to which one?