LED Spotlights only flash once when turned on.

[Steve35]

Needing some help here:

We've got a set of 3 halogen spotlights on landing in our house, with a switch at the top and bottom of the stairs.
The fittings are (according to the label on them) able to handle up to 20W halogen (MR11 type) and they currently have 14W halogens in each.

We have tried to replace these halogens with 3W MR11 GU4.0 LED bulbs to save on electricity usage but now all they do when turned on is flash once and then go dark.
They don't flicker, or stay on at all; they just flash once than that is it, almost as if they have shorted out or tripped a fuse. All the fuses and circuit breakers are unchanged when this happens.

We've tried 2 different types of LED bulbs in these fittings and get the same response from either type.
I've tried using a mixture of LED and old Halogen bulbs but again the same. And I've even tried only fitting a single LED or leaving one fitting empty, again the exact same thing happens.

We've got larger 3.5W MR16 bulbs in other fittings in the house, all of which work perfectly.

We're at a total loss as to what the problem is, any ideas?

 

[securespark]

Sounds like an issue of compatibility with the ELECTRONIC TRANSFORMERS. What does it say on the units supplying these lamps?

 

[Steve35]

Good question, but the ballast/transformer (?) is in the loft under a load of flooring so i'm currently not able to check.

I've finally managed to get them to work by installing a random Halogen bulb we had sitting around, so for some reason they will work with one halogen and 2 LED bulbs in place.

Is it possible the supply unit thinks there's nothing connected as they use such low power? Hence why they will work with a halogen bulb installed that draws more power. That was something suggested elsewhere online but i'm totally clueless when it come to this sort of thing!

 

[Taylortwocities]

Is it possible the supply unit thinks there's nothing connected as they use such low power?

Yes, You often need a different sort of power supply for LEDs (aka LED driver). The halogen-type supplies often need at least a 20watt load to work properly.

The better solution is to ditch the need for converters and power supplies altogether and install 230v LED lamps.
In every case you nedd to be able to access the old supplies. Usually you can get to then through the downlight hole.

There is a similar problem if you have a dimmer, many of those also need a decent sized load. A LED-compatible one is needed there too.

 

[333rocky333]

The better solution is to ditch the need for converters and power supplies altogether and install 230v LED lamps.
In every case you nedd to be able to access the old supplies. Usually you can get to then through the downlight hole.

Sounds good, but maybe not so easy to do, with mr11 35mm diameter lamps.

Are these 3 seperate lights or three lights all on one light fitting
if downlights maybe better too fit mr16 fittings.

If they are downlights it sounds strange theres 3 on one transformer, the maximum lamp you could buy was a 35watt, as that was the most common, it could have been fatal for the transformer if youd not read the label and fitted three 35watts and odd for a downlight to be 20w rated.

If he had fitted a 100w transformer that would have tended to have a 35watt load minimum, then that would unlikely work properly with your 1 halogen 2 led combo,

Maybe the installer/maker just cut costs by allowing the 20w fitting rating 3 x 20w on just one 20-60 watt transformer.
I have a feeling there not downlights but some sort of 3 lamp fitting, due to the 20watt max label.

 

[winston1]

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Pointless squabbling is no longer required

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