Flashing low-voltage downlights - help!!!
Joe Cocker
to fit some low-voltage downlights in the room.
I bought 6 lights (http://www.tlc-direct.co.uk/Products/QLDL50W.html) and 2
x 250W transformers (http://www.tlc-direct.co.uk/Products/LTYT250.html),
each to power 3 lights.
Fitted them earlier this week, all worked well for a few minutes, and then
one set of 3 lights (all on the same transformer) started to flash, i.e.
every 30 secs or so the light would cut off, then immediately come back on,
etc...
Spoke to the guys at TLC who assured me that they had never experienced any
problems with these transformers. They even put me though to the
manufacturer of the transformers, and he asked me to return them for
testing. He explained that they have a heat sensor that cuts them off if
required, but he was convinced that with my set up there was clearly no need
for that to happen. He mentioned that they should be placed up-right to
ensure the heat sensor works correctly (which they were). He also suggested
that I would buy 6 individual 70W transformers instead just to make sure
everything works OK.
Well, I just received those
(http://www.tlc-direct.co.uk/Products/LTYT70.html), fitted them, and you
guessed it, the flashing from a couple of them continues.
I can obviously return them all for a refund and buy transformers elsewhere,
but before I do that, does anyone have any idea what is going on?
A few other points worth noting:
- The transformers are placed in a large attic with plenty of space, and all
roof insulation around them was removed.
- Both 250W's were worryingly hot when the lights were switched on.
- A friend who is a very competent electrician checked my setup and wiring
and could not fault it.
- The bathroom is not yet fitted, so there is no moisture in the room.
Cheers,
Joe.
John Jardine
Joe Cocker <j_co...@REMOVEMEhotmail.com> wrote in message
news:SsPza.1050$OP4...@newsfep1-gui.server.ntli.net...
have, seem to be excessively loading the transformer and are acting more
like 100watt versions than 50watt.
Maybe pull a bulb out and see if the wattage is marked on them.
If you have a meter, measure the AC current out of the transformer whilst
the bulbs are on. There should be about 12 amps flowing.
regards
john
AWM
"Joe Cocker" <j_co...@REMOVEMEhotmail.com> wrote in message
news:SsPza.1050$OP4...@newsfep1-gui.server.ntli.net...
decided
> to fit some low-voltage downlights in the room.
>
> I bought 6 lights (http://www.tlc-direct.co.uk/Products/QLDL50W.html) and
2
> x 250W transformers (http://www.tlc-direct.co.uk/Products/LTYT250.html),
> each to power 3 lights.
>
> Fitted them earlier this week, all worked well for a few minutes, and then
> one set of 3 lights (all on the same transformer) started to flash, i.e.
> every 30 secs or so the light would cut off, then immediately come back
on,
> etc...
It sounds like some kind of internal protection device is tripping, then
resets, all these transformers get warm but not hot but just in case I
always mount them on plaster board not wood.
I tried to look at the gear on the web site but changed my mind because the
site trys to download cookies -- however one thing I have noticed when
looking at LV lighting transformer specs is that they surprisingly specify a
minimum load which going by the type Wickes sell is about 2/3 the max rated
load, I had assumed this was because bulb life would be shortened but it
just could be the cause of your problem.
Woodspoiler
because the
site trys to download cookies
What's so bad about cookies? A great many sites put cookies on
your PC. I can't understand why you wouldn't view a page on a
site like that one because the web server wants to give you a
cookie. If you're really bothered, you can usually block cookies
from the browser and still view the page. On that particular
site, the cookies are probably used to remember who you are, so
if you are a returning customer, say, you don't have to type your
details into an order again, or to help them track how people
move from page to page through the site so they can improve the
design. What's wrong with that?
Cookies in themselves are not bad. It may be possible to abuse
the cookie mechanism, but usually cookies are innocent and
harmless. If the cookie control tools in your browser don't go
far enough, you can get third-party programs to manage them and
still view most Web pages.
W.
Ray
the ones that are flashing touching earth in anyway? Ray
BigWallop
"Joe Cocker" <j_co...@REMOVEMEhotmail.com> wrote in message
news:SsPza.1050$OP4...@newsfep1-gui.server.ntli.net...
Hi Joe,
It sounds as though you have the lights wired in parallel rather than in
series. By the way you are describing the fault of really hot trannies' and
the thermal safety cut-outs activating.
A 250w transformer is meant to run 5 X 50w lamps running in a series wiring
configuration, from one lamp to the next in the line, and not to run 5 X 50w
lamps running individually wired as this drops the total resistance of the
circuit down and causes your symptoms, so check the wiring again.
BigWallop
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Outgoing mail is certified Virus Free.
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IanJH
"BigWallop" <spamguard@_spam_guard_.com> wrote in message
news:js0Aa.2585$Gf.18...@news-text.cableinet.net...
>
> "Joe Cocker" <j_co...@REMOVEMEhotmail.com> wrote in message
> news:SsPza.1050$OP4...@newsfep1-gui.server.ntli.net...
> > I am in the process of re-fitting my bathroom, and at the same time
> decided
> > to fit some low-voltage downlights in the room.
> >
> > I bought 6 lights (http://www.tlc-direct.co.uk/Products/QLDL50W.html)
and
> 2
> > x 250W transformers (http://www.tlc-direct.co.uk/Products/LTYT250.html),
> > each to power 3 lights.
> >
> > Fitted them earlier this week, all worked well for a few minutes, and
then
> > one set of 3 lights (all on the same transformer) started to flash, i.e.
> > every 30 secs or so the light would cut off, then immediately come back
> on,
> > etc...
>
> Hi Joe,
>
> It sounds as though you have the lights wired in parallel rather than in
> series. By the way you are describing the fault of really hot trannies'
and
> the thermal safety cut-outs activating.
>
> A 250w transformer is meant to run 5 X 50w lamps running in a series
wiring
> configuration, from one lamp to the next in the line, and not to run 5 X
50w
> lamps running individually wired as this drops the total resistance of the
> circuit down and causes your symptoms, so check the wiring again.
>
> BigWallop
>
>
Awww I wanted to say that :-) BigWallop is always first and usually right..
bugger.. lol
IanJH
ARWadsworth
> >
> > It sounds as though you have the lights wired in parallel rather than in
> > series. By the way you are describing the fault of really hot trannies'
> and
> > the thermal safety cut-outs activating.
> >
> > A 250w transformer is meant to run 5 X 50w lamps running in a series
> wiring
> > configuration, from one lamp to the next in the line, and not to run 5 X
> 50w
> > lamps running individually wired as this drops the total resistance of
the
> > circuit down and causes your symptoms, so check the wiring again.
> >
> > BigWallop
> >
> >
>
> Awww I wanted to say that :-) BigWallop is always first and usually
right..
> bugger.. lol
>
> IanJH
>
>
output from the transformer is 12v and putting the lights in series would
make them very dim.
Adam
AWM
"Woodspoiler" <woods...@nochoppedhamwithpork.icsh.demon.co.uk> wrote in
message news:baq0nl$61g$1...@titan.btinternet.com...
> >I tried to look at the gear on the web site but changed my mind
> because the
> site trys to download cookies
>
Other words for cookies are spambots and spyware
AWM
"BigWallop" <spamguard@_spam_guard_.com> wrote in message
news:js0Aa.2585$Gf.18...@news-text.cableinet.net...
snip
>
> It sounds as though you have the lights wired in parallel rather than in
> series. By the way you are describing the fault of really hot trannies'
and
> the thermal safety cut-outs activating.
>
Don't listen to this dork
THEY SHOULD BE WIRE IN PARRALLEL usually they are chained but still in
parrallel
Andy Dingley
<spamguard@_spam_guard_.com> wrote:
>A 250w transformer is meant to run 5 X 50w lamps running in a series wiring
>configuration,
Rubbish ! This would require an output voltage under load of 60V,
and considerably higher when open circuit. I've never seen such a
beast (intended for low voltage lighting) and I don't believe they
exist. Please quote a catalogue reference for one.
If you're using a transformer, then match the lamp and transformer
ratings closely. This unit isn't a transformer though, it's some form
of switched mode PSU with active voltage regulation. It should be OK,
but then it's made by Ring.
There are two possibilities I can think of:
The ratings are mis-matched. Try temporarily wiring 5 of the lamps
onto one PSU and seeing if that cures it.
The lampholders have poor contacts. This is a perennial problem with
dichroics, especially when mounted to run hot. This load spike cold be
enough to confuse the PSU.
Personally I'd run a bench rig of 5 and see if they still did it. If
they did, I'd take them back to TLC for a refund (and a stroppy letter
to Ring).
If they didn't do it on the bench, I'd replace the PSU's anyway and
swallow the expense. If it's intermittent or thermally related, it's
barely worth the hassle of arguing with the supplier for a refund (but
try it anyway).
Tim..
> It sounds as though you have the lights wired in parallel rather than in
> series. By the way you are describing the fault of really hot trannies'
and
> the thermal safety cut-outs activating.
>
> A 250w transformer is meant to run 5 X 50w lamps running in a series
wiring
> configuration, from one lamp to the next in the line, and not to run 5 X
50w
> lamps running individually wired as this drops the total resistance of the
> circuit down and causes your symptoms, so check the wiring again.
>
This is incorrect. All 12v halogens run off 12v as supplied by the
transformer, so whether you run individual radial circuits to each fitting,
or daisy chain them makes no difference- they are always wired in parallel.
If you did mistakenly wired them in series the combined resistance of the
bulbs at 12v would cause them to light very very dimly, if at all.
Tim..
Tim..
---
Outgoing mail is certified Virus Free.
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Woodspoiler
Cookies, spambots and spyware are different things entirely.
I have built Web sites including back-end programming, written
software and done PC tech support professionally. I am very aware
of the differences and the issues. This is very OT, however, so I
will leave it there. There are loads of places on the Web that
explain these things in great detail.
W.
ARWadsworth
> transformer, so whether you run individual radial circuits to each
fitting,
> or daisy chain them makes no difference- they are always wired in
parallel.
> Tim..
>
Some multiple feed transformers have paired/balanced outputs (Aurora
certainly do some models like this). The lights must be run individually
from these transformers and not daisy chained from another 12v light. The
result is the daisy chained lights are dimmer than the individually wired
lights. I doubt this is the problem here though as pulsing lights are a
classic symptom of overheating or a faulty transformer.
Try swapping the transformers over and see how they work when powering the
other 3 lights.
Adam
yorkie boy
Are lamps to be wired in series or individually.........Isn't it a better
bet for each lamp to have its own transformer even though this costs
slightly more?????????
ARWadsworth
"yorkie boy" <ma...@bay20.fsnet.co.uk> wrote in message
news:bar0e2$js6$1...@newsg1.svr.pol.co.uk...
> Having read the posts on this subject I am still very confused!!!!!!!!!
> Are lamps to be wired in series
NO.
Isn't it a better
> bet for each lamp to have its own transformer even though this costs
> slightly more?????????
Yes.
AWM
To explain
The usual way for LV lighting to be wired is in a line but they are still in
parrallel, the only problem with this is the last lamps in the line get
lower voltage because of the longer length of conductor. A better way to do
it is to wire them in a star configuration with the transformer in the
centre -- this means the voltage drop to each lamp will be the same (and
less) and all should be of equal brightness.
Series wiring was what was used n the old xmas tree lights -- 20 bulbs
each 12 volts wired in series accross a 240v mains supply, problems are one
bulb blows they all go out and also you can get a 240 volt shock off any
part of the system.
The Natural Philosopher
Some cheapo switched mode PSUS don't run at part load.
That could be it in fact - try a toroid. No interfence either.
The Natural Philosopher
Not my transmformes it ain't. They all run in parallell.
BigWallop
"ARWadsworth" <adamwa...@blueyonder.co.uk> wrote in message
news:Zv1Aa.2691$OE.18...@news-text.cableinet.net...
Hi Adam,
If you have a look at the links provided in the original post, you'll notice
no mention of voltage output. These units are rated at 0w - 250w output and
are compatible with dimmer units, so I still stick to what I wrote in my
reply and ask if anyone here has actually fitted a series wired switch mode
power supply, the nature of which allows a constant current at equally
rising or falling load voltage.
A building in Calander Park, Falkirk used this type of unit, albeit a bit
bigger output rating, and they worked a treat, especially if a lamp popped
which made us test each one on the line until we found the culprit.
Anyway, back to work now. See ya.
BigWallop
Dave Plowman
BigWallop <spamguard@_spam_guard_.com> wrote:
> If you have a look at the links provided in the original post, you'll
> notice no mention of voltage output. These units are rated at 0w - 250w
> output and are compatible with dimmer units, so I still stick to what I
> wrote in my reply and ask if anyone here has actually fitted a series
> wired switch mode power supply, the nature of which allows a constant
> current at equally rising or falling load voltage.
> A building in Calander Park, Falkirk used this type of unit, albeit a
> bit bigger output rating, and they worked a treat, especially if a lamp
> popped which made us test each one on the line until we found the
> culprit.
> Anyway, back to work now. See ya.
I *think* you mean spur wired as opposed to radial. Series wired, as has
been explained to you, means something totally different. However, neither
option would cause the OP's fault, IMHO.
--
*Experience is something you don't get until just after you need it.*
Dave Plowman dave....@argonet.co.uk London SW 12
RIP Acorn
The Natural Philosopher
Lampos are wired in parallel, it is slightly better for each one to have
its own transformer yes, but not mandatory.
ARWadsworth
>
> If you have a look at the links provided in the original post, you'll
notice
> no mention of voltage output.
Actually there is. On the link for the transformer
http://www.tlc-direct.co.uk/Products/LTYT250.html
there is a link labelled technical and its output is 11.5 volts max.
Adam
BigWallop
Sorry Adam, my wording is wrong (I was tired :-) LOL ). I meant that these
units are set at a constant voltage rated output for low voltage lighting,
DOH !, and they keep that voltage under differing load situations but, they
also raise or lower their amperage output, as stated on their labels, up to
a maximum of 32 amperes, which is why I said that the 5 X 50w lamps should
be wired in a series pattern on this type of switched mode regulator.
I think I should have a sleep before I answer in the group and stop getting
all me amps and volts and resistance jumbled up. I suppose it's old
catching up. I still wonder why my body is going to need such long nasal
hair as it gets older. :-? LOL
use...@isbd.co.uk
>
> "ARWadsworth" <adamwa...@blueyonder.co.uk> wrote in message
> news:70OAa.1809$RS7.14...@news-text.cableinet.net...
>> > Hi Adam,
>> >
>> > If you have a look at the links provided in the original post, you'll
>> notice
>> > no mention of voltage output.
>>
>> Actually there is. On the link for the transformer
>> http://www.tlc-direct.co.uk/Products/LTYT250.html
>> there is a link labelled technical and its output is 11.5 volts max.
>> Adam
>>
>>
>
> Sorry Adam, my wording is wrong (I was tired :-) LOL ). I meant that these
> units are set at a constant voltage rated output for low voltage lighting,
> DOH !, and they keep that voltage under differing load situations but, they
> also raise or lower their amperage output, as stated on their labels, up to
> a maximum of 32 amperes, which is why I said that the 5 X 50w lamps should
> be wired in a series pattern on this type of switched mode regulator.
>
in parallel to the nominally 12 volt 'transformer'.
--
Chris Green (cgr...@x-1.net)
The Natural Philosopher
Haven't you worked out yet that Big Wallop doesn't actually understand
basic electical language definitions, let alone theory?
>
STH
Well, you really got a bum steer from the first reply but there is
much wisdom in the following ones however, one point to check is the
rating of the transformer. As with all but super-cooled devices your
transformer will have 'losses' in itself so when you 'spec' it for you
lights match the OUTPUT rating against your lights not the INPUT. If
you only have an INPUT spec for power then allow 20% overhead for the
transformer losses, eg: 5x50W = 250W PLUS 20% (50W) and you need a
300W unit.
STH.
use...@isbd.co.uk
aren't they, except possibly the rating on the plate on the
transformer itself which *might* indicate the maximum load it can
impose on the supply.
If you buy a '150 watt transformer' it means one that can supply a 150
watt load. If it could only manage somewhat less than this I think
you'd have a pretty good case for returning it to the supplier and
trading standards would be very interested too I would think.
Taking it to ridiculous lengths one could otherwise sell a big
resistor in a box and claim it was a transformer which was xxx watts
input but (rather inefficiently) zero watts output.
--
Chris Green (cgr...@x-1.net)
Dave Plowman
<use...@isbd.co.uk> wrote:
> As with all but super-cooled devices your
> > transformer will have 'losses' in itself so when you 'spec' it for you
> > lights match the OUTPUT rating against your lights not the INPUT. If
> > you only have an INPUT spec for power then allow 20% overhead for the
> > transformer losses, eg: 5x50W = 250W PLUS 20% (50W) and you need a
> > 300W unit.
> >
> All ratings for transformers of this type are surely output ratings
> aren't they, except possibly the rating on the plate on the
> transformer itself which *might* indicate the maximum load it can
> impose on the supply.
I'd also query the 20% losses. It could only go in heat, and 20% of 150
watts in a small space would get very hot.
--
*Okay, who stopped the payment on my reality check? *
Joe Cocker
transformers powering 3 x50W light.
So, am I correct in assuming that this isn't the problem? Also, I have the
same problem with several 70W transformers powering individual 50W light
each.
"Dave Plowman" <dave....@argonet.co.uk> wrote in message
news:4bfa5f3c0c...@argonet.co.uk...
Joe Cocker
transformers powering 3 x50W light.
So, am I correct in assuming that this isn't the problem? Also, I have the
same problem with several 70W transformers powering individual 50W light
each.
"Dave Plowman" <dave....@argonet.co.uk> wrote in message
news:4bfa5f3c0c...@argonet.co.uk...
Dave Plowman
Joe Cocker <j_co...@REMOVEMEhotmail.com> wrote:
> Thanks for the advice. However, the problem I encountered were with a
> 250W transformers powering 3 x50W light.
> So, am I correct in assuming that this isn't the problem? Also, I have
> the same problem with several 70W transformers powering individual 50W
> light each.
Are these ordinary transformers or electronic types?
Also, what made you use ones which are too large rather than the correct
ones?
--
*Succeed, in spite of management *
Joe Cocker
> In article <OiwBa.4017$bN2...@newsfep1-gui.server.ntli.net>,
> Joe Cocker <j_co...@REMOVEMEhotmail.com> wrote:
> > Thanks for the advice. However, the problem I encountered were with a
> > 250W transformers powering 3 x50W light.
>
> > So, am I correct in assuming that this isn't the problem? Also, I have
> > the same problem with several 70W transformers powering individual 50W
> > light each.
>
> Are these ordinary transformers or electronic types?
Electronic I believe. They are
http://www.tlc-direct.co.uk/Products/LTYT250.html and
http://www.tlc-direct.co.uk/Products/LTYT70.html.
> Also, what made you use ones which are too large rather than the correct
> ones?
Ordered them as part of a larger order from TLC, and these were the most
suitable ones that they stocked. They assured me prior to ordering that they
were suitable for my setup.
Cheers,
Joe.
Dave Plowman
Joe Cocker <j_co...@REMOVEMEhotmail.com> wrote:
> > Are these ordinary transformers or electronic types?
> Electronic I believe. They are
> http://www.tlc-direct.co.uk/Products/LTYT250.html and
> http://www.tlc-direct.co.uk/Products/LTYT70.html.
Right. These have auto protection against overloading and overheating. I'd
guess it's one of these. Does the flickering start as soon as they are
switched on?
--
*Rehab is for quitters.
Joe Cocker
> In article <wHEBa.1008$9H6...@newsfep1-gui.server.ntli.net>,
> Joe Cocker <j_co...@REMOVEMEhotmail.com> wrote:
> > > Are these ordinary transformers or electronic types?
>
> > Electronic I believe. They are
> > http://www.tlc-direct.co.uk/Products/LTYT250.html and
> > http://www.tlc-direct.co.uk/Products/LTYT70.html.
>
> Right. These have auto protection against overloading and overheating. I'd
> guess it's one of these. Does the flickering start as soon as they are
> switched on?
Yes, you are right, they do have overheating protection.
The flickering (I believe) starts after a few minutes which made me
suspicious about overheating as well, especially as the last few days have
been warmer than usual.
Having said that, I am in sunny (NOT!) Glasgow, and the temperature is
rarely above 20c. The transformers are in a large attic space above the
bathroom, and all the insulation around them as been removed. It is
therefore possible that they get too hot, but considering my situations how
would someone leaving somewhere in the South of the country stand a chance
with them in the summer?
I am getting close to returning the 70W back for a refund as well as neither
the 250W nor the 70W came with any documentation and I have no idea of their
spec.
The Natural Philosopher
> In article <bb5pjg$671qc$2...@ID-61610.news.dfncis.de>,
> <use...@isbd.co.uk> wrote:
>
>>As with all but super-cooled devices your
>>
>>>transformer will have 'losses' in itself so when you 'spec' it for you
>>>lights match the OUTPUT rating against your lights not the INPUT. If
>>>you only have an INPUT spec for power then allow 20% overhead for the
>>>transformer losses, eg: 5x50W = 250W PLUS 20% (50W) and you need a
>>>300W unit.
>>>
>>>
>>All ratings for transformers of this type are surely output ratings
>>aren't they, except possibly the rating on the plate on the
>>transformer itself which *might* indicate the maximum load it can
>>impose on the supply.
>>
>
> I'd also query the 20% losses. It could only go in heat, and 20% of 150
> watts in a small space would get very hot.
>
Transformer effiociency varies considerably: Wind em with little wires
and not much iron and they get hotter.
Pro substaion ones are better than 97%. Cheapo toroids for lights -
maybe 80% or less.
Switched mode 'electronic' transformers? Hmm. Dunno,. Maybve 85-90%
efficient at a pure guess.
>