GU10s to LED

[John Duffy]

Can you not just change the bulbs rather than the whole fitting? You might have to change the dimmer as well as some dimmers don't like leds

And some LEDs don't like dimmers...

 

[stuart little]

Wall plate dimmers are invariably of the "phase control" type - they are cheap & cheerful and essentially vary the power delivery from 0% to 100% for an incandescent device like a halogen bulb.

LEDs do not dim - they are either ON or OFF (they don't dim) - you get the ILLUSION of dimming by using PWM, Pulse Width Modulation, where the LED is switched VERY rapidly on for say 10% and off for 90% which gives the ILLUSION (as your eyes have persistence of vision) of a 10% bright LED. LEDs therefore generally need PWM rather than phase control dimmers.

You can easy see the rapid on/off switching of LEDs by spreading out your fingers in front of your eyes and shaking your hand up and down - the fingers will appear to "freeze" just like in a old strobe light - LEDs turn on and off immediately as they are solid-state devices and have no thermal lag (unlike halogens).

Some modern LED units are smart enough to interpret phase-control and change that internally to PWM, but it's a nasty hack. Just do a proper job and change the dimmers to PWM as well.

PWM dimmers should also work with incandescent bulbs.

Except in the showers, I replaced all our MR11/MR16 lights (52 of them) with 230VAC GU10 LEDs and removed all the transformers (nasty things, unreliable). It's worth noting that LED MRxx bulbs often have real problems with electronic 12V "transformers" as the electronic 12V transformers often require a minimum current draw to work correctly and a LED replacement may be 5W instead of 50W, so the bulb may not light at all, flicker on and off, or "sing",

That's also why traffic lights & some vehicle lights appear to be flashing on film & TV.

 

[Spectric]

An LED can be dimmed by controlling the forward current or using PWM, but with LED bulbs we are not just talking about an LED but often an array of LED's and a built in switching power supply. The dimmer switchs we use are phase cutters that will either chop the first half or the second half of the Ac waveform, for LED bulbs you want to cut the second half which means you control the off point but the older types cut off the first half meaning you control the on point.

 

[leisurefix]

Worth mentioning that a 12v transformer & 50W bulb use more than just the 50W of the bulb and you may well have 6 transformers. When we got a smart meter (now there is something for another topic ) I was shocked how much 4 of them used on reduced light levels. Could be 0.5KW total if you care about that kind of thing. So in my view worth paying to have it all removed & replaced with LED. Sorry, don't know if it's notifiable.

 

[HOJ]

don't know if it's notifiable.

Seemingly not:

 

[Sachakins]

If they on halogen 12v driver/transformers, you'll need to change them to 12v led drivers.
I just tried to replace 12v 35w halogen to 12v led's and they wouldn't work, worked fine with new 12v led driver. Dimmers for dimmable 240v led bulbs are available but don't know if or how they'll work with 12v led drivers?

 

[ShavedSpoke]

We had 12v Mr16 lights throughout our upstairs, some on dimmers. For a few years I tried numerous MR16 dimmable LEDs from all the top brands - Osram, Philips, GE - and also changed all the drivers to specialist dimmable LED drivers. In the end I gave it all up as a bad job. They're all rubbish AFAICT.

I swapped them all to 240v GU10 fittings (in fact, I did the last 4 up in the loft yesterday. horrible job). Luckily nothing is in Zone 0 or 1, although I did fit IP65 fittings above the shower, even though the ceiling is high.

Personally I've found that the GU10 LEDs seem more reliable, and don't seem so fussy about dimming. Most are not on a dimmer, but the room that is I'm using a Varilight V-Pro dimmer which can be switched between leading and trailing edge dimming, so should be compatible with most dimmable LED bulbs.

 

[Spectric]

Notifiable: Quote

The Building Regulations set out overall criteria and requirements to ensure electrical safety in and around dwellings. Approved Document P provides further practical guidance for undertaking this type of work. You should bear in mind that any electrical work you carry out within your home, garden, garage shed and other storage buildings may need to comply with the requirements of the Building Regulations. These works are called notifiable work.

Very common examples of notifiable work are; rewiring a property, providing electricity to a garage or outhouse, the replacement of the main fuse box in a house or any electrical work in a kitchen, shower room or bathroom.

 

[HOJ]

From Part P:





My understanding is, that unless the work is within the specified zones it is not notifiable.

 

[Spectric]

The bathroom is classed as a special location where there are increased hazzards from electrocution and all work should only be undertaken by a qualified electrician who will issue you with appropriate certification. The problem is that any work outside of the zones could still lead to electrocution, ie a wet floor might be outside of any zone.

 

[HOJ]

all work should only be undertaken by a qualified electrician

That's becoming a debatable point in its own right, I've been on a big kitchen and utility fit out the last couple of weeks, we had an "electrician" come and replace the main board and do some connects for power, turns out he's not "qualified" in the sense of any C & G's or NVQ's and gets a mate of his to sign the work off, if and when its needed (he did have and use a tester).

That's yet another reason I dropped the Part P registration quite some time ago.

 

[rs6mra]

rather annoying that such a straightforward job is notifiable.

 

[Spectric]

He might have been a domestic installer, these are minimal training to do installations in domestic property and are doer's not thinkers. If all goes to plan they get away wth it but often when they hit a snag they need help. The person taking the risk is his mate because unless he does a full test and inspection then if anything happens he will be the bloke who they come after.

 

[HOJ]

a domestic installer, these are minimal training to do installations in domestic property and are doer's not thinkers

I looked that up, these schemes are ridiculous, 10 days at a training center and 5 days of online learning, WTF, I spent 5 years chasing my ass
to get a ticket, and apparently I'm not qualified, with my C & G - A, B & C's.

Glad I'm well out of it.

 

[Spectric]

These are essentially the creation of the property developer who wanted to cut cost of house building. They had cut cost out of everything but electricians were deemed to expensive to in their words " throw some wires into a house " so the domestic installer was created to throw some wires into a house for the property developers. Yes I fully appreciate your thoughts on the hours you spend becoming an electrical engineer to understand the underlying theory and complex equations found in Ac electrical theory and gaining an ability to fault find to end up in a world where they now use trained monkeys.

Look at the other trades that are no longer used, carpenters to fit a cut roof are gone and matchstick trusses are the norm, decent plumbers have gone and now plastic pipe and pushfit fittings with no skill required in fitting and no bending of copper pipe. The property developer now use house builders who do a bit of everything to chuck up a glorified shed to maximise profits for the share holders.

 

[Terry - Somerset]

These are essentially the creation of the property developer who wanted to cut cost of house building. They had cut cost out of everything but electricians were deemed to expensive to in their words " throw some wires into a house " so the domestic installer was created to throw some wires into a house for the property developers. Yes I fully appreciate your thoughts on the hours you spend becoming an electrical engineer to understand the underlying theory and complex equations found in Ac electrical theory and gaining an ability to fault find to end up in a world where they now use trained monkeys.

Look at the other trades that are no longer used, carpenters to fit a cut roof are gone and matchstick trusses are the norm, decent plumbers have gone and now plastic pipe and pushfit fittings with no skill required in fitting and no bending of copper pipe. The property developer now use house builders who do a bit of everything to chuck up a glorified shed to maximise profits for the share holders.

I agree with all you say - the "trades" have become entirely deskilled as far as housebuilding is concerned. Implied criticism of property developers may be unjustified - we, the consumers, chase functionality and low prices.

Would we be prepared to pay 10 or 20% more for a house which has been built using the skills of trained artisans in the black arts of carpentry, plumbing, electrics etc etc. I doubt it when the alternative provides precisely the same apparent functionality.

Even taking a longer perspective - would there be a benefit in the traditional when it comes to longevity, ability to modify and extend etc. Personally unconvinced except where short term cost savings compromise long term flexibility - eg: roof structures inhibit or add cost to loft extensions

 

[Spectric]

I doubt it when the alternative provides precisely the same apparent functionality.

That is a phrase I remember from the auto industry, the phrasing used back then was perceived quality to help justify cost cutting. Anything could be made cheaper providing the customer would not perceive it as cheap or actually see it.

we, the consumers, chase functionality and low prices.

That rings bell with woodworking machinery, we complain when a machine fails to deliver expectations but at the same time want a cheap machine.

 

[HOJ]

carpenters to fit a cut roof are gone and matchstick trusses are the norm

I posted before a cut roof I had done, interestingly they had a price of £6K for Fink trusses, which still required a lot of loose timbers to be cut and shut on site, and was a major compromise on the objective of creating the roof space they wanted.

The bill for the all timber I used was £1900.00 and the engineers bill was £400.00, labour was about £3K so all in £5.3K inc VAT.

So they saved money and got what they wanted, however they couldn't find a "carpenter" willing or able to do it in the first place, hence the call to me, but its not rocket science...