I have had 6 50W 12v halogen GU5.3 downlighters in one room for years.

I am replacing them with LEDs. But I don't think the transformers I have will cope with the very low current draw from each LED.

So I am planning to replace them with 240v GU10s instead, bypassing the need for transformers.

I want to do this neatly and safely. I have new GU10 connectors, these have a simple 2 pole chocolate box on the end. I can directly remove the transformers, and wire these direct to the mains lighting cable in the ceiling.

But I want to do this neatly/safely. so I need to cover the choclate boxes. I could just use insulation tape, but that does not meet neatly/safely.

I am considering usings these 5A inline connectors:

edit. Cannot work out how to post an image link. No dropdowns for attachments/links etc visible...
so plain text links:

https://imgur.com/a/IJOJG
original image at
http://www.rpssolar.co.uk/pics/5ajunc.JPG


They all emphasise 'flex' rather than cable. Is this an issue? Are they suitable/appropriate, or is there something more 'standard/recommended? I need them small enough to feed through the MR16 holes in the ceiling.


As an aside. Why do people use 12v downlighters (with the added expense of the transformers) when 230V appears to be fine?

Neal

On Mon, 18 Dec 2017 08:38:34 -0800, Neal wrote:

====snip====


As an aside. Why do people use 12v downlighters (with the added expense
of the transformers) when 230V appears to be fine?


The 12v filaments are significantly more robust than their 240v
counterparts and, for wattages in the range of 20 to 35 (possibly
including 50 which I think is the absolute max for quartz halogen GU10
lamps), offer better luminous efficacy.

When we had our downstairs shower/toilet refurbished some 7 or 8 years
ago, the wife insisted on replacing the single 60W bulb with a set of
four recessed down lighters and I agreed only if 12v bulbs were fitted.

To this day, we are still on the original set of 35W halogens. However,
rather than the electricians using classic step down transformers, to my
surprise they'd actually fitted electronic "transformers" rated for a
maximum of 60W at 12v (presumably to cater for the possibility of fitting
50W lamps).

These will current limit at just a tad over their 5A rating which
significantly reduces the inrush current on switch on[1] (which is the
major driver of filament lamp failure) further enhancing their longevity
so I'm not altogether surprised at how long the lamps have lasted thus
far. It's a triple 'whammy' of improvement, if you will, over the cheaper
240v lamp option since the electronic 'transformers' offer even more
inrush current limiting protection than the old fashioned magnetic
transformers ever could.

[1] This current inrush protection is clearly evident in the short, 300ms
or so, delay in ramping up to full brightness on switch on.

--
Johnny B Good

In article ,
Neal wrote:
As an aside. Why do people use 12v downlighters (with the added expense
of the transformers) when 230V appears to be fine?

That style of lamp first appeared only as low voltage. The mains version
came later. I have both, and the low voltage ones produce slightly more
light - and the bulbs last longer.

The low voltage type also allow a wider range of fittings because of the
safe voltage.

I dunno if the 12v LED replacements are any better than the 240v ones in
practice. LEDs don't need high volts to drive them, so its possible the
internal bulb PS is easier with low volts. If so, would it be possible to
re-group yours so one transformer feeds several - therefore above the
minimum load?

--
*I'm not being rude. You're just insignificant

Dave Plowman London SW
To e-mail, change noise into sound.

Thanks to both Jonny and Dave - that makes sense

Dave- considered 1 transformer, but all the wiring is hidden above ceiling, along with junction boxes splitting the wires. Likely impossible to access the primary feed to insert a transformer there, given access is only through the lamp holes.

Neal

On 18/12/2017 16:38, Neal wrote:
I want to do this neatly and safely. I have new GU10 connectors, these have a simple 2 pole chocolate box on the end.

Now that toberlone have increased the gap between the 'peaks',
will choc blocks have to be re-designed too ?.

In article ,
Neal wrote:
Thanks to both Jonny and Dave - that makes sense

Dave- considered 1 transformer, but all the wiring is hidden above
ceiling, along with junction boxes splitting the wires. Likely
impossible to access the primary feed to insert a transformer there,
given access is only through the lamp holes.

Does that mean you already have more than one fitting per transformer?

I used those small electronic transformers that fit through the same
ceiling hole as the fitting - to make repair easy, if needed. Some of
those may work OK with LEDs - have you tried them?

--
*Caution: I drive like you do.

Dave Plowman London SW
To e-mail, change noise into sound.