MR11/U4 bulb holder question

[DrZepster]

Hi

When I recently replaced one of our 23(!) kitchen halogens the wire to the bulb holder broke.  I'm looking at replacements but few actually quote the specified amps and if they do they are invariably too low, for instance the cheap chinese holders on Amazon is all 2Amp max, but with 35W lights they need to be 4A.  The original company, Aurora, have now moved on to Smart LED technology so I don't hold out much hope that they will have a replacement. 

Ultimately, I feel that the wire failed because I have to replace the halogens so often, they are always going, and due to the cost of running them I have replaced half with LEDs, but worry that replacing them all will fall below the transformer's minimum rating and cause the dreaded flickering.  Having now pulled the entire fixture from the ceiling (with the mess that ensued) in order to access the terminals for the lamp holder wires I note that the low voltage transformer is dimmable.  Could I get away with replacing all the bulbs with LEDs or should I just bite the bullet and rip them all out and replace with non-low voltage lamps?

Many thanks

Ross

 

[ProDave]

Do yourself a favour and swap them all to LED lamps.

23 lamps at 35W each means your kitchen uses 805 watts in lighting.  That is for times what my whole house uses if I turn every single light on.

4W LED lamps will give the same light output and with the much reduced current you will never have another problem with the lamp holders failing.

I used to really really hate downlighters because of the appalling waste of energy. Until LED lamps matured and got cheap enough.

 

[DrZepster]

I agree, it's ridiculous (not my choice, we inherited it when we moved here), the 23 are in 2 rings, 9 inner, 14 outer, I've replaced roughly half with LEDs already but worried that of I replace them all then the load will be too low for the transformers.

 

[Geoff1946]

but worried that of I replace them all then the load will be too low for the transformers.

I wouldn't even try running led lamps off transformers designed for halogen. They are quite different beasts.

Use either the correct led "drivers", which are actually a regulated transformer rectifier unit, OR use mains halogen lamps which effectively have the driver built in.

A point with led downlighters is that they are more directional than halogens which can result in pools of light, but with the number you have that's probably not an issue. Do however look for the widest beam spread angle you can.

 

[ProDave]

The other solution is ditch the transformers, change all the lamp holders to GU10 and fit mains voltage LED's

 

[Murdoch]

The other solution is ditch the transformers, change all the lamp holders to GU10 and fit mains voltage LED's

that doesn’t work on all low voltage fittings as the GU10 lamps are bigger

 

[DrZepster]

that doesn’t work on all low voltage fittings as the GU10 lamps are bigger

Yes, the current package has a 50mm diameter hole, and looking at the company's GU10 fitting on TLC(https://www.tlc-direct.co.uk/Products/AUFD101PC.html)  it requires a 75 mm hole instead.  This may not be a bad thing, removing the current one creates no end of mess around the hole, so cutting another will negate that.

However, having now pulled one out the ceiling at least I now know that each unit is fed by it's own dimmable electronic transformer, whereas I assumed that each ring of lights would have it's own transformer.  Presumably I can replace all the lamps with LEDs since none of the current ones flicker, however as Geoff1946 pointed out these are presumably the wrong drivers for LEDs.

 

[roys]

I would rip out the halogen fittings and transformers, out of date inefficient technology. Fit mains GU10 fittings, as you have already found out a lot of them require a cutout of about 70mm which I’d ideal if the current hole is 50mm.

Because the hole is already there the hole saw will have problems centering. One way round this is temporarily screw a bit of timber behind the hole so that the holesaw has something  to center in.

when you buy your GU10 lamps (bulbs) make sure they are dimmable and buy the dimmer to suit it. Buy the fittings that have replaceable lamps as the integrated ones are a PITA, if you don’t  when one of them stops working a year down the line and you have to try and find a matching fitting rather than just changing a lamp.

 

[NozSpark]

Some hole saw arbours have enough space for 2 hole saws..... so if you fit a 50mm inside the 70mm it will centre it for you

 

[kerching]

Some hole saw arbours have enough space for 2 hole saws..... so if you fit a 50mm inside the 70mm it will centre it for you

Armed make an adaptor as do,Starret

or, as some of us do/did. Made our own out of a big set screw and a couple of nuts. Cannot recall the thread size but, if I remember correctly, a member on here sent me a couple of the correct sized bolts

 

[Murdoch]

Yes, the current package has a 50mm diameter hole, and looking at the company's GU10 fitting on TLC(https://www.tlc-direct.co.uk/Products/AUFD101PC.html)  it requires a 75 mm hole instead.  This may not be a bad thing, removing the current one creates no end of mess around the hole, so cutting another will negate that.

However, having now pulled one out the ceiling at least I now know that each unit is fed by it's own dimmable electronic transformer, whereas I assumed that each ring of lights would have it's own transformer.  Presumably I can replace all the lamps with LEDs since none of the current ones flicker, however as Geoff1946 pointed out these are presumably the wrong drivers for LEDs.

if you decide to replace all the lamp holders with Gu10 then you must ensure you have earth continuity from the last light back to the fuse board

 

[BorisJ]

Do you really need 23? The fact that you are dimming them (in a kitchen where you need good light) suggests you don't. I would be looking at filling some of the holes and using GU10s in the others.