I have some Low Voltage kitchen ceiling lights, each with its own
transformer. Recently, one of them has run for about a minute and then gone
out. I've checked for overheating which was my first guess, but it's not
that. I've also checked for loose connections but no luck there either.
Any suggestions?

Regards

Pat Macguire

Syke explained :
I have some Low Voltage kitchen ceiling lights, each with its own
transformer. Recently, one of them has run for about a minute and then gone
out. I've checked for overheating which was my first guess, but it's not
that. I've also checked for loose connections but no luck there either.
Any suggestions?


Could you perhaps try swapping that particular one for one of the
others and see if the fault moves with the 'transformer'?

Most likely it will be the 'transformer' (a switch mode power supply in
fact) and the only solution will be to replace it.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

On Thu, 21 Aug 2008 21:42:46 +0100, "Syke"
wrote:

I have some Low Voltage kitchen ceiling lights, each with its own
transformer. Recently, one of them has run for about a minute and then gone
out. I've checked for overheating which was my first guess, but it's not
that. I've also checked for loose connections but no luck there either.
Any suggestions?

It's possible that the bulb you used was of too low a wattage, which
means that because of poor transformer regulation the voltage getting
to it was too high. For instance, if the fitting is designed for a 50W
bulb and you have only a 20W bulb you could be overrunning it, even if
the nominal voltage is correct..

Check that the bulbs are the correct rating for the fitting.

--
Frank Erskine

On Aug 21, 9:42*pm, "Syke" wrote:
I have some Low Voltage kitchen ceiling lights, each with its own
transformer. Recently, one of them has run for about a minute and then gone
out. *I've checked for overheating which was my first guess, but it's not
that. *I've also checked for loose connections but no luck there either..
Any suggestions?

Regards

Pat Macguire

bad transformer - assuming the transformer is running a lamp of
wattage its specced to


NT

In article ,
Frank Erskine wrote:
I have some Low Voltage kitchen ceiling lights, each with its own
transformer. Recently, one of them has run for about a minute and then
gone out. I've checked for overheating which was my first guess, but
it's not that. I've also checked for loose connections but no luck
there either. Any suggestions?

It's possible that the bulb you used was of too low a wattage, which
means that because of poor transformer regulation the voltage getting
to it was too high. For instance, if the fitting is designed for a 50W
bulb and you have only a 20W bulb you could be overrunning it, even if
the nominal voltage is correct..

Check that the bulbs are the correct rating for the fitting.

Can't see that causing the PS to shut down then come on again. Unless the
OP means the bulb is blowing.

--
*The statement below is true.

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

In article ,
Syke wrote:
I have some Low Voltage kitchen ceiling lights, each with its own
transformer. Recently, one of them has run for about a minute and then
gone out. I've checked for overheating which was my first guess, but
it's not that. I've also checked for loose connections but no luck
there either. Any suggestions?

Can you get at the 'transformers' easily? If so swap the affected one with
another. Some types fit through the fitting hole so are quite easy to
change. If the fault moves with the transformer you have the answer.
But my guess is you've got a SMPS rather than transformer type and it's
developed a fault. They are so cheap you just replace them.

--
*Hard work has a future payoff. Laziness pays off NOW.

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

Syke wrote:
I have some Low Voltage kitchen ceiling lights, each with its own
transformer. Recently, one of them has run for about a minute and then gone
out. I've checked for overheating which was my first guess, but it's not
that. I've also checked for loose connections but no luck there either.
Any suggestions?

Regards

Pat Macguire


iF it is a toroid transformer, it may have a fauly thermal trip. Out of
about 40 of these I had one DOA and one that overheated once, and ended
up like yours. Just replaced both.

"Syke" wrote in message
...
I have some Low Voltage kitchen ceiling lights, each with its own
transformer. Recently, one of them has run for about a minute and then
gone
out. I've checked for overheating which was my first guess, but it's not
that. I've also checked for loose connections but no luck there either.
Any suggestions?

I have similar problems with LV lights and transformers basically in the
Summer (when its hotter) one or two LC lights goes off after couple of
minutes.

One was a faulty transformer, replacing cured the problem.

Other was transformer was lying in the insulation in kitchen roof. Managed
to push insulation away and stand the transformer directly on the
plasterboard and works fines.

"Dave Plowman (News)" wrote in message
...
In article ,
Syke wrote:
I have some Low Voltage kitchen ceiling lights, each with its own
transformer. Recently, one of them has run for about a minute and then
gone out. I've checked for overheating which was my first guess, but
it's not that. I've also checked for loose connections but no luck
there either. Any suggestions?

Can you get at the 'transformers' easily? If so swap the affected one with
another. Some types fit through the fitting hole so are quite easy to
change. If the fault moves with the transformer you have the answer.
But my guess is you've got a SMPS rather than transformer type and it's
developed a fault. They are so cheap you just replace them.

They are so cheap its not worth testing them IMO.

Replace lamp (~50p) and then transformer (~275p).

Syke wrote:
I have some Low Voltage kitchen ceiling lights, each with its own
transformer. Recently, one of them has run for about a minute and
then gone out. I've checked for overheating which was my first
guess, but it's not that. I've also checked for loose connections
but no luck there either. Any suggestions?

Regards

Pat Macguire

Thanks for the replies. I have ordered two transformers from Screwfix (1
spare).

Regards

Pat Macguire