LED’s - what did I do wrong?

[nickd01]

So I bought 10 Amazon Basics, dimmable, 12v led’s to replace the kitchen lights. I wanted to see if LED’s work for us.
Stuck them in and it just blows the fuse under the stairs.
What is so badly wrong with them? I’m no expert but I’m a bit lost. I didn’t think that’d happen!

[V8RX7]

Are you sure they should be 12v (ie you have transformers) not 240v ?

[nickd01]

The existing bulbs are labelled 12v and there looks like a ‘box’ in the cieling above each individual bulb. I assume that’s a transformer thingy.

[mjb1]

Most old low voltage transformers/drivers designed for halogen lamps don't like the low current of LED bulbs. If each light has it's own driver then you're probably stuck with changing the fitting to get LEDs to work. If a single driver supplies several lamps, you might get away with swapping out half (or maybe more) of the halogens for LEDs before the driver stops coping.

[Pintofbest]

Power draw would be more important, I know they are LED but what is the power? Or could you have a rogue one with a fault maybe?

[nickd01]

Thanks for the ideas.

I can try them in the loo as it’s only got 2 lights so easier to try. I can then more easily elimate a dodgy bulb.

The existing ones are 50w, these LED’s are marked as ‘5w to 35w’

[buggalugs]

Take them out and put them in one or two at a time

Could be something coincidental like a damaged fitting

[nickd01]

So it’s okay to ‘mix’ the different light types?

[mintybiscuit]

You do realise that you will need an LED compatible dimmer switch ?

[nickd01]

mintybiscuit said:

You do realise that you will need an LED compatible dimmer switch ?

I admit I've heard of them but couldn't work out what type I had and whether it'd work. I got the impression they'd simply not dim correctly rather than blow the fuse but maybe that could be the issue.

Thanks - I'd completely forgotten about that.

[hairyben]

nickd01 said:

I admit I've heard of them but couldn't work out what type I had and whether it'd work. I got the impression they'd likey not dim correctly rather than blow the fuse but maybe that could be the issue.

correct. have you tried putting all the old bulbs back in and does the circuit work normally, ie not trip? Very odd that a 12v LED should trip a circuit as it's not connected directly to the 230v side, the transformer sits between.

[nickd01]

hairyben said:

correct. have you tried putting all the old bulbs back in and does the circuit work normally, ie not trip? Very odd that a 12v LED should trip a circuit as it's not connected directly to the 230v side, the transformer sits between.

I actually put them all back, and one of the bulbs didn't light back up. Whether the bulb has blown or something more sinister I don't know. I'll check tonight.

Maybe I shouldn't have gone for 'cheap' LED's ?

I think step one would be to check on the smaller circuit in the loo that just has two lights in whether the LED's even light up or work. I can go from there.

[buggalugs]

I replaced 12 50W GU10 halogens in the kitchen with LED's about 4 years ago, they were just on a standard dimmer. I found that the lights would flicker badly when dimmed, but I read a tip to put one or two halogens back in to put some load on it and it was fine then, still fine now.

Now I've replaced the 50W halogens that were in for load with non-dimmable LED's I think they were IKEA ones and they keep the rest of the LED's rock solid, when you turn the dimmer down the rest dim and those two just cut out at a certain point. I only found that out by fluke I just wanted to see what they looked like next to the others.

Hopefully someone will find my rambling useful...

[Dr_Rick]

I think it's more simple than all of the above comments.

We have the same start point: a bunch of GU4 / MR11 12V halogen fittings on a dimmer. I want to change them to LED as I have approx 18 of these things at 20W+ each.

Doing some research, I have a couple of options:
- Swap out all the fittings for mains (240V) fittings to take dimmable LED bulbs, or
- Swap out the individual transformers for 12V, LED compatible dimmable units, and fit 12V LED dimmable bulbs.

The first appeals to me as at present whenever anything blows I have to find out whether the bulb has gone or the transformer has gone and hold stocks of both, just in case. Option 1 means if it goes, I just buy a new unit. Option 2 means new bulbs and new transformers.

I'm not convinced about the need for a new dimmer switch. It's just a potentiometer isn't it? It's feeding 0-240V out from a 240V feed, whether it be to a 12V system via a transformer or to a 240V bulb.

[nickd01]

Ah, maybe my transformers aren't up to the task. I've no idea what spec they are.
This is starting to sound a lot more complex than I originally planned!

[Alucidnation]

Just remove the tranny and fit a gu10 lamp holder.

Simple.

[Sheepshanks]

Dr_Rick said:

I'm not convinced about the need for a new dimmer switch. It's just a potentiometer isn't it? It's feeding 0-240V out from a 240V feed, whether it be to a 12V system via a transformer or to a 240V bulb.

If it's an older dimmer and there's not enough load it won't work properly.

Stuff about dimmers here: https://www.lightbulbs-direct.com/article/dimming-... I use my existing dimmer to dim my LED bulbs?

[Alucidnation]

Most dimmers will cope with an led load, however some can self destruct or even kill the lamp so it’s always better fit the proper unit.

[boyse7en]

This is something I was thinking of tackling as I'm fed up of replacing bulbs/transformers on our kitchen lights.

Currently got 12 35W Halogen 'eyeball' light fittings running off three transformers (so four lights per transformer)

Is it better to buy three new transformers and 12 MR16-size LED bulbs, or to completely replace the fittings?

[megaphone]

boyse7en said:

This is something I was thinking of tackling as I'm fed up of replacing bulbs/transformers on our kitchen lights.

Currently got 12 35W Halogen 'eyeball' light fittings running off three transformers (so four lights per transformer)

Is it better to buy three new transformers and 12 MR16-size LED bulbs, or to completely replace the fittings?

I would remove the transformers and fit 230v LED GU10 lamps. You should be able to use the existing fitting, you'll need to change the lamp holder to GU10, something like this

https://www.screwfix.com/p/luceco-gu10-gz10-lampho...