Still struggling with deciding how to update the ceiling lighting.

If I go for low volt downlighters, is it normal for each downlight
unit to have its own separate transformer?

If so I presume normal 1.0 or 1.5 mm2 cable can be daisy chained to
each outlet? & that then gives the flexibility to allow switching
between LV & HV units later?

Or am I misunderstanding something?

Any experiences of fitting & cabling downlighters would be much
appreciated.

TIA

On 26/07/2010 10:57, jim wrote:
Still struggling with deciding how to update the ceiling lighting.

If I go for low volt downlighters, is it normal for each downlight
unit to have its own separate transformer?


You can get both sorts - either with built-in individual transformers,
or with a separate one serving several lamps.

The ones which I installed about 8 years ago had separate transformers
(I'm not sure that the other sort were available at the time) and the
ones which an electrician installed in our refurbished kitchen last year
had individual built-in transformers.

If so I presume normal 1.0 or 1.5 mm2 cable can be daisy chained to
each outlet?& that then gives the flexibility to allow switching
between LV& HV units later?

Or am I misunderstanding something?


That's precisely right - you just feed mains to each lamp's transformer,
so you can mix and match. Having experienced both sorts, I would
certainly go the individual transformer route in future. With the other
route you need fairly hefty cables between transformer and lamps because
they are carrying much more current and you can't afford any appreciable
voltage drop. You also need to be able to access the transformers via a
lamp hole in case they need replacing - but with the other sort, the
transformer comes out with the lamp.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On 26 July, 10:57, jim wrote:
Still struggling with deciding how to update the ceiling lighting.

If I go for low volt downlighters, is it normal for each downlight
unit to have its own separate transformer?


Not compulsory but usually easier nowadays.


If so I presume normal 1.0 or 1.5 mm2 cable can be daisy chained

Look for trafos with loop through, set of mains terminals in and out,
makes daisy chaining easier.

to
each outlet? *& that then gives the flexibility to allow switching
between LV & HV units later?

It keeps cable size under control and no cost adavantages any longer
to single large transformer.


Or am I misunderstanding something?

Sounds like your understanding is good, you`ve already made right
choice with LV arther than GU10 ;-)

Cheers
Adam

Any experiences of fitting & cabling downlighters would be much
appreciated.

TIA

"Adam Aglionby" wrote in message
...
On 26 July, 10:57, jim wrote:
Still struggling with deciding how to update the ceiling lighting.

If I go for low volt downlighters, is it normal for each downlight
unit to have its own separate transformer?


Not compulsory but usually easier nowadays.


If so I presume normal 1.0 or 1.5 mm2 cable can be daisy chained

Look for trafos with loop through, set of mains terminals in and out,
makes daisy chaining easier.

to
each outlet? & that then gives the flexibility to allow switching
between LV & HV units later?

It keeps cable size under control and no cost adavantages any longer
to single large transformer.


Or am I misunderstanding something?

Sounds like your understanding is good, you`ve already made right
choice with LV arther than GU10 ;-)

Cheers
Adam

Any experiences of fitting & cabling downlighters would be much
appreciated.

TIA

I would go for mains units then you can change the bulbs for led ones when
the prices come down. Good ones are around £15.00 each at the moment. Saves
the cost of the transformer etc. Just need to do your sums !

On Jul 26, 10:57*am, jim wrote:
Still struggling with deciding how to update the ceiling lighting.

If I go for low volt downlighters, is it normal for each downlight
unit to have its own separate transformer?

If so I presume normal 1.0 or 1.5 mm2 cable can be daisy chained to
each outlet? *& that then gives the flexibility to allow switching
between LV & HV units later?

Or am I misunderstanding something?

Any experiences of fitting & cabling downlighters would be much
appreciated.

TIA

4x the number of transformers means 4x the failure rate


NT

On 26 July, 21:17, NT wrote:
On Jul 26, 10:57*am, jim wrote:

Still struggling with deciding how to update the ceiling lighting.

If I go for low volt downlighters, is it normal for each downlight
unit to have its own separate transformer?

If so I presume normal 1.0 or 1.5 mm2 cable can be daisy chained to
each outlet? *& that then gives the flexibility to allow switching
between LV & HV units later?

Or am I misunderstanding something?

Any experiences of fitting & cabling downlighters would be much
appreciated.

TIA

4x the number of transformers means 4x the failure rate

NT

Not a satistician , but sure there someat wrong with that.

Besides good trafos, Mode and IBL are good, will last many years.

Cheap trafos are 1.99 so odsd failure few years perfectly acceptable.

Cheers
Adam

On Jul 26, 10:59*pm, Adam Aglionby wrote:
On 26 July, 21:17, NT wrote:



On Jul 26, 10:57*am, jim wrote:

Still struggling with deciding how to update the ceiling lighting.

If I go for low volt downlighters, is it normal for each downlight
unit to have its own separate transformer?

If so I presume normal 1.0 or 1.5 mm2 cable can be daisy chained to
each outlet? *& that then gives the flexibility to allow switching
between LV & HV units later?

Or am I misunderstanding something?

Any experiences of fitting & cabling downlighters would be much
appreciated.

TIA

4x the number of transformers means 4x the failure rate

NT

Not a satistician , but sure there someat wrong with that.

Its simple statistics. Same failure rate for each one, 4 times the
failures per given time, equals 4x the failure rate.


NT

On 26 July, 23:54, NT wrote:
On Jul 26, 10:59*pm, Adam Aglionby wrote:



On 26 July, 21:17, NT wrote:

On Jul 26, 10:57*am, jim wrote:

Still struggling with deciding how to update the ceiling lighting.

If I go for low volt downlighters, is it normal for each downlight
unit to have its own separate transformer?

If so I presume normal 1.0 or 1.5 mm2 cable can be daisy chained to
each outlet? *& that then gives the flexibility to allow switching
between LV & HV units later?

Or am I misunderstanding something?

Any experiences of fitting & cabling downlighters would be much
appreciated.

TIA

4x the number of transformers means 4x the failure rate

NT

Not a satistician , but sure there someat wrong with that.

Its simple statistics. Same failure rate for each one, 4 times the
failures per given time, equals 4x the failure rate.

NT

Thanks for the explanation, see where your getting at, but MBTF I
think would be to 50% fail which would leave half working with 4.

At least a single failure won`t leave you in the dark with multiple
trafos ;-)

Cheers
Adam

On Jul 26, 11:59*pm, Adam Aglionby wrote:
On 26 July, 23:54, NT wrote:



On Jul 26, 10:59*pm, Adam Aglionby wrote:

On 26 July, 21:17, NT wrote:

On Jul 26, 10:57*am, jim wrote:

Still struggling with deciding how to update the ceiling lighting..

If I go for low volt downlighters, is it normal for each downlight
unit to have its own separate transformer?

If so I presume normal 1.0 or 1.5 mm2 cable can be daisy chained to
each outlet? *& that then gives the flexibility to allow switching
between LV & HV units later?

Or am I misunderstanding something?

Any experiences of fitting & cabling downlighters would be much
appreciated.

TIA

4x the number of transformers means 4x the failure rate

NT

Not a satistician , but sure there someat wrong with that.

Its simple statistics. Same failure rate for each one, 4 times the
failures per given time, equals 4x the failure rate.

NT

Thanks for the explanation, see where your getting at, but MBTF I
think would be to 50% fail which would leave half working with 4.

At least a single failure won`t leave you in the dark with multiple
trafos ;-)

Cheers
Adam


I reckon 2 or sometimes 3 transformers is about ideal

FWIW, the comparison I'm making is one failure per MTBF compared to 4
failures per MTBF.


NT

On 26 July, 22:59, Adam Aglionby wrote:
///////

Many thanks for most informative replies,,however

Besides good trafos, Mode and IBL are good, will last many years.

What is a 'trafo'? please 'scuse my ignorance but I read it at first
as 'transformer' but not sure....

Also any (web) pointers to suitable units. The only one found so far
with fittings & bulbs which appears in keeping with the various B. Reg
rules is the TCL (http://www.tlc-direct.co.uk)


Cheap trafos are 1.99 so odsd failure few years perfectly acceptable.

web pointer to 1.99 units would help & also perhaps throw light on
meaning of 'trafo'

TIA

On Jul 29, 11:09*pm, jim wrote:
On 26 July, 22:59, Adam Aglionby wrote:
///////

Many thanks for most informative replies,,however



Besides good trafos, Mode and IBL are good, will last many years.

What is a 'trafo'? *please 'scuse my ignorance but I read it at first
as 'transformer' but not sure....

Also any (web) pointers to suitable units. *The only one found so far
with fittings & bulbs which appears in keeping with the various B. Reg
rules is the TCL (http://www.tlc-direct.co.uk)



Cheap trafos are 1.99 so odsd failure few years perfectly acceptable.

web pointer to 1.99 units would help & also perhaps throw light on
meaning of 'trafo'

TIA

transformer

On 29 July, 23:09, jim wrote:
On 26 July, 22:59, Adam Aglionby wrote:
///////

Many thanks for most informative replies,,however



Besides good trafos, Mode and IBL are good, will last many years.

What is a 'trafo'? *please 'scuse my ignorance but I read it at first
as 'transformer' but not sure....

Also any (web) pointers to suitable units. *The only one found so far
with fittings & bulbs which appears in keeping with the various B. Reg
rules is the TCL (http://www.tlc-direct.co.uk)



Cheap trafos are 1.99 so odsd failure few years perfectly acceptable.

web pointer to 1.99 units would help & also perhaps throw light on
meaning of 'trafo'

TIA

Is this on..

Sorry about other post google groups was having an off day


Yup, you read it right, its just my lazy typing.

Usual suspects , Screwstation, Toolfix, TLC, local electrical
wholesalers.

Recession converts wholesalers view from `who`s calling.....?`
to
` We welcome cash sales` :-)


Local independent wholesaler had a box of 10 for 19.99 + VAT.

Screwfix have a box of 10 for 28.90 or so.

http://www.screwfix.com/prods/67836/...mer-Pack-of-10

TBH cheap trafos are for hit and run developers, its worth spending
extra couple quid a point of you live with it.

Cheers
Adam

In article
s.com, Adam Aglionby scribeth thus
Sorry about other post google groups was having an off day


Yup, you read it right, its just my lazy typing.

Usual suspects , Screwstation, Toolfix, TLC, local electrical
wholesalers.

Recession converts wholesalers view from `who`s calling.....?`
to
` We welcome cash sales` :-)

Don't they just now, and some are good for a few bob more off the price
if you pay them by debit card or bounceless cheque..

After all credit accounts cost to administer, and theres always someone
going tits up to take your profits....


--
Tony Sayer