Issues with Recessed Lighting - Advice please

Westmeath Lass

Hi All,

A little bit of advice if possible please? In our kitchen we have 6 recessed lights all on one circuit. House was built circa 2004 & the transformers on the lights are currently Robus transformers. We bought the house two years ago & one of the lights stopped working. We got electrician out to have a look and one of the transformers was blown. The other night it happened again. We think that it could be the same light of the six but this time none of the lights will work, So my husband went today and bought a new transformer, He has linked them all up as before, Turned on the fuse & it blew again. This is leading me to believe that perhaps one of the others are gone and the current is bouncing back... Could this be the case or could the fuse be faulty?

Thanks in advance for any help

Jen

freddyuk

Are they halogen 50 watt lamps?

Westmeath Lass

Hi Freddy,

Yes - The old transformer is a Robus 70VAMAX 11.4 VAC - Guy in the shop said that they dont do these any more and he gave Starlite 20-60VA Model EU-2060, He said that the 50v bulbs would still work with these.

Thanks

freddyuk

I would suggest you check all the other transformers. I pulled all mine out to replace with LED's (mains) and discovered two had been severely damaged by the heat of the lamps to the extent they were melted right through to the core and could easily have caught light.
The transformers should be supported away from the lamps but rarely are in practice.
Worth a look.

2011

It is very hard to diagnose without seeing it. The first transformer may have "expired" for a different reason than the replacement. Robus are a good make. I don't know the other make, but from your description it is suitable.

These transformers have a primary side that you must connect the mains to (230V) and a secondary (about 12V) that should be connected to the lamp. If the primary and secondary were mixed this would cause it to fail.

2011

Another possibility is that there is a short circuit somewhere downstream of the transformer. This could be in the lamp, lamp holder, or wiring between the fitting and the transformer. This problem can be found by a process of elimination or with a multimeter.

Bruthal

2011 wrote: »

Another possibility is that there is a short circuit somewhere downstream of the transformer. This could be in the lamp, lamp holder, or wiring between the fitting and the transformer. This problem can be found by a process of elimination or with a multimeter.

You would of thought the saturation point at secondary short circuit of that size traffo would be well below the MCB tripiping level. Certainly for wire wound it would.

Electronic ones would just trip internally, or fail on secondary short circuit.

Unless a secondary side short destroyed the traffo to such an extent that it tripped the MCB.

Interesting point though.

meercat

Also just check that you wired the replacement trafo correctly
There's an input side and an output side
If this was done wrong,then you will need a new transformer again
Check the bulb and the bulb holder too

2011

robbie7730 wrote: »

You would of thought the saturation point at secondary short circuit of that size traffo would be well below the MCB tripiping level. Certainly for wire wound it would.

From reading the OP my impression is that the MCB never tripped, but the original transformer failed. Then both replacement transformers failed.

canttellyou

meercat wrote: »

Also just check that you wired the replacement trafo correctly
There's an input side and an output side
If this was done wrong,then you will need a new transformer again
Check the bulb and the bulb holder too

Ya, what he said ha

2011

meercat wrote: »

Also just check that you wired the replacement trafo correctly
There's an input side and an output side
If this was done wrong,then you will need a new transformer again
Check the bulb and the bulb holder too

Sounds like posts 5 & 6 :D

pipsdad

Or do away with all transformers and fit GU10 fly leads.

M cebee

not sure about this business of fitting gu-10 flyleads

prob ok for diy

meercat

2011 wrote: »

Sounds like posts 5 & 6 :D

Yeah sorry
Should have copied and paste
Read replies quick and didn't take all info in
Thanks

Bruthal

2011 wrote: »

From reading the OP my impression is that the MCB never tripped, but the original transformer failed. Then both replacement transformers failed.

You could be alright, i was getting the impression they meant the MCB when they said they turned on the fuse and it blew again. And none of the light will work.

But its a bit vague alright.

Bruthal

meercat wrote: »

Also just check that you wired the replacement trafo correctly
There's an input side and an output side
If this was done wrong,then you will need a new transformer again
Check the bulb and the bulb holder too

It seems to have worked after the electrician replaced the transformer, then all 6 lights went off.

So before the OP replaced the same transformer again, there was already a problem tripping all the 6 lights, and the rest of the downstairs ones too if it was the MCB tripping.

So the OP could of replaced a transformer that had no problem. With all 6 not working after the initial transformer replacement, it could of been any of them, or a problem anywhere on the entire lighting circuit.

All 6 lights would need to be checked for a start anyway, bulbs, holders, transformers etc.

meercat

Agree
check the switch too
Especially if it's a dimmer switch

pipsdad

M cebee wrote: »

not sure about this business of fitting gu-10 flyleads

prob ok for diy

At least it'll do away with any transformer issue altogether, IMO unless its a safety issue (damp areas, public accessability to fittings etc) I don't understand why MR16's are used anyway, whats the benefit?

2011

pipsdad wrote: »

I don't understand why MR16's are used anyway, whats the benefit?

Superior light quality.

pipsdad

2011 wrote: »

Superior light quality.

In what way superior? I have both in kitchen and TBH they look the same.

M cebee

pipsdad wrote: »

M cebee wrote: »

not sure about this business of fitting gu-10 flyleads

prob ok for diy

At least it'll do away with any transformer issue altogether, IMO unless its a safety issue (damp areas, public accessability to fittings etc) I don't understand why MR16's are used anyway, whats the benefit?

the12volt halogen were a better light than mains

the issue with flyleads is people are converting a 12 volt fitting into a 230v fitting

and connecting long flyleads into joints-the flylead should form part of fitting
prob alright for diy work

2011

pipsdad wrote: »

In what way superior?

Color rendering.

"The color rendering index (CRI) (sometimes called color rendition index), is a quantitative measure of the ability of a light source to reproduce the colors of various objects faithfully in comparison with an ideal or natural light source."

From this link:
http://en.wikipedia.org/wiki/Color_rendering_index

Although LEDs are getting better in terms of CRI, the vast majority are geared towards power efficiency/efficacy and looking white rather than handling all colors correctly.


There is a comparsion between MR16 halogen lamps and LED type lamps shown in this report:

http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/mr16_benchmark_11-08.pdf

Here is an extract:
"The color characteristics of LED MR16 replacement lamps varied in CALiPER testing. Most of the tested LED products had CCT values similar to those of the halogen MR16 lamps. However, three of the LED replacement lamps produced a very cool white light with CCT values near or above 6000 K "

2011

Apologies, I see that this type of LED discussion should be here:

http://www.boards.ie/vbulletin/showthread.php?t=2056469034

pipsdad

2011 wrote: »

Color rendering.

"The color rendering index (CRI) (sometimes called color rendition index), is a quantitative measure of the ability of a light source to reproduce the colors of various objects faithfully in comparison with an ideal or natural light source."

From this link:
http://en.wikipedia.org/wiki/Color_rendering_index

Although LEDs are getting better in terms of CRI, the vast majority are geared towards power efficiency/efficacy and looking white rather than handling all colors correctly.


There is a comparsion between MR16 halogen lamps and LED type lamps shown in this report:

http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/mr16_benchmark_11-08.pdf

Here is an extract:
"The color characteristics of LED MR16 replacement lamps varied in CALiPER testing. Most of the tested LED products had CCT values similar to those of the halogen MR16 lamps. However, three of the LED replacement lamps produced a very cool white light with CCT values near or above 6000 K "

What is LED to do with it? The OP has halogens, nobody mentioned LED? So in what way is the quality of light better from MR16 vs GU10?

M cebee

your question has been answered already
its common knowledge
hardly worthy of debate

MastiffMrs

Similar thing happened with my spotlights in hallway. Robus transformers also. Our house was built in 2005 and currently 3 of the 8 transformers have blown. I brought one into a lighting shop and was told that there was obvious signs that there had been over heating and that they were dangerous and we should replace all spotlights. Is this an over reaction? They told me that they don't sell these any more and that the new spotlights dont heat up.
There was evidence of mice chewing on the wiring also.
Any suggestions of what we should do? Presume it'd be big money to replace 8 spotlights, wiring etc?

pipsdad

Get GU10 fittings and do away with transformers altogether. (awaits slapdown:rolleyes:)

2011

pipsdad wrote: »

Get GU10 fittings and do away with transformers altogether.

Many people do exactly that. There are pros and cons to doing this.
Here is the place to discuss this option:

http://www.boards.ie/vbulletin/showthread.php?t=2056469034

kerryaviva

M cebee wrote: »

not sure about this business of fitting gu-10 flyleads

prob ok for diy

why not those trafos should be banned they over heat constantly and sometimes are red hot to touch get a sparks and replace with luminex 11 watt cfl gu 10 bulbs .;)

pipsdad

Don't mention the traffos vs GU10 fly leads thing here, some do be very defensive about quality of light and the like and then you'll be directed to read a LED thread for some reason. :rolleyes:

kerryaviva

pipsdad wrote: »

Don't mention the traffos vs GU10 fly leads thing here, some do be very defensive about quality of light and the like and then you'll be directed to read a LED thread for some reason. :rolleyes:

ya i know that some people get very uptight about these things im just giving my input those trafos are dangerous yet people still install them in ceiling voids that is crammed with in sulation and then wonder why there lights keep tripping the mcbs i have made a small fortune in correcting these things.;)