I have four halogen LV downlighters in my kitchen, controlled by one
dimmer switch. All of them use dimmer transformers. I once had to
change the chocolate box on one of them that melted, but other than
that they have given three years of trouble free operation.

Recently they have been failing to turn on. This affects all of the
lights, not just one. I noticed that if I turned the dimmer down (made
the light more dim) they would then come on, and turning the dimmer
back up would turn them off again.

It's rather intermittent, sometimes they turn on fine at full power,
other times not.

I took a look in the switch unit but all the connections seem fine
there.

Any other ideas?

"Dan Gravell" wrote in message
...
I have four halogen LV downlighters in my kitchen, controlled by one
dimmer switch. All of them use dimmer transformers. I once had to
change the chocolate box on one of them that melted, but other than
that they have given three years of trouble free operation.

Recently they have been failing to turn on. This affects all of the
lights, not just one. I noticed that if I turned the dimmer down (made
the light more dim) they would then come on, and turning the dimmer
back up would turn them off again.

It's rather intermittent, sometimes they turn on fine at full power,
other times not.

I took a look in the switch unit but all the connections seem fine
there.

Any other ideas?

Replace dimmer with normal switch and see if they work OK

If so replace dimmer switch

Tony

Replace dimmer with normal switch and see if they work OK

If so replace dimmer switch

Tony

Will do

On Fri, 22 Jan 2010 09:09:49 -0800 (PST), Dan Gravell wrote:

I have four halogen LV downlighters in my kitchen, controlled by one
dimmer switch. All of them use dimmer transformers. I once had to
change the chocolate box on one of them that melted, but other than
that they have given three years of trouble free operation.

Recently they have been failing to turn on. This affects all of the
lights, not just one. I noticed that if I turned the dimmer down (made
the light more dim) they would then come on, and turning the dimmer
back up would turn them off again.

It's rather intermittent, sometimes they turn on fine at full power,
other times not.

I took a look in the switch unit but all the connections seem fine
there.

Any other ideas?

Have several 12v downlighters in my kitchen, two have been troublesome, not
always coming on, though I don't use a dimmer. The bulb connectors have
proved to be a bit problematical, I found the cables need to come out of
the bulb connector more or less straight up. If the cables are bent at any
sort of angle, the lights don't always come on. Very often, just the action
of removing the bulb retaining ring from the fitting and easing the light
down would make it light, then it would go out again when the bulb was
secured back into the fitting.

I have a bungalow, and dressing the wires into a different position from
the loft rather than trying to bend the wires from below through the
fitting seems to have cured the problem


--
The Wanderer

I want to die how my Grandad died, peacefully, in his sleep,
Not like his passengers, who were screaming and shouting!

The Wanderer expressed precisely :
On Fri, 22 Jan 2010 09:09:49 -0800 (PST), Dan Gravell wrote:

I have four halogen LV downlighters in my kitchen, controlled by one
dimmer switch. All of them use dimmer transformers. I once had to
change the chocolate box on one of them that melted, but other than
that they have given three years of trouble free operation.

Recently they have been failing to turn on. This affects all of the
lights, not just one. I noticed that if I turned the dimmer down (made
the light more dim) they would then come on, and turning the dimmer
back up would turn them off again.

It's rather intermittent, sometimes they turn on fine at full power,
other times not.

I took a look in the switch unit but all the connections seem fine
there.

Any other ideas?

Have several 12v downlighters in my kitchen, two have been troublesome, not
always coming on, though I don't use a dimmer. The bulb connectors have
proved to be a bit problematical, I found the cables need to come out of
the bulb connector more or less straight up. If the cables are bent at any
sort of angle, the lights don't always come on. Very often, just the action
of removing the bulb retaining ring from the fitting and easing the light
down would make it light, then it would go out again when the bulb was
secured back into the fitting.

I have a bungalow, and dressing the wires into a different position from
the loft rather than trying to bend the wires from below through the
fitting seems to have cured the problem

Most likely the lamp-holder to lamp connections. They run a lot of
current and with a lot of heat. The lamp pins and lamp-holder
connections tend to burn and become high resistance. Look at the lamp
pins, they should be clean and polished, if not fit new lamp holders
and lamp as a pair - they are not expensive.

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

"The Wanderer" wrote in message
...
On Fri, 22 Jan 2010 09:09:49 -0800 (PST), Dan Gravell wrote:

I have four halogen LV downlighters in my kitchen, controlled by one
dimmer switch. All of them use dimmer transformers. I once had to
change the chocolate box on one of them that melted, but other than
that they have given three years of trouble free operation.

Recently they have been failing to turn on. This affects all of the
lights, not just one. I noticed that if I turned the dimmer down (made
the light more dim) they would then come on, and turning the dimmer
back up would turn them off again.

It's rather intermittent, sometimes they turn on fine at full power,
other times not.

I took a look in the switch unit but all the connections seem fine
there.

Any other ideas?

Have several 12v downlighters in my kitchen, two have been troublesome,
not
always coming on, though I don't use a dimmer. The bulb connectors have
proved to be a bit problematical, I found the cables need to come out of
the bulb connector more or less straight up. If the cables are bent at any
sort of angle, the lights don't always come on. Very often, just the
action
of removing the bulb retaining ring from the fitting and easing the light
down would make it light, then it would go out again when the bulb was
secured back into the fitting.

I have a bungalow, and dressing the wires into a different position from
the loft rather than trying to bend the wires from below through the
fitting seems to have cured the problem


--
The Wanderer

I want to die how my Grandad died, peacefully, in his sleep,
Not like his passengers, who were screaming and shouting!


You have a bad connection. You MUST fix it as it is a fire risk.

On Fri, 22 Jan 2010 18:53:44 GMT, Harry Bloomfield wrote:

The Wanderer expressed precisely :
On Fri, 22 Jan 2010 09:09:49 -0800 (PST), Dan Gravell wrote:

I have four halogen LV downlighters in my kitchen, controlled by one
dimmer switch. All of them use dimmer transformers. I once had to
change the chocolate box on one of them that melted, but other than
that they have given three years of trouble free operation.

Recently they have been failing to turn on. This affects all of the
lights, not just one. I noticed that if I turned the dimmer down (made
the light more dim) they would then come on, and turning the dimmer
back up would turn them off again.

It's rather intermittent, sometimes they turn on fine at full power,
other times not.

I took a look in the switch unit but all the connections seem fine
there.

Any other ideas?

Have several 12v downlighters in my kitchen, two have been troublesome, not
always coming on, though I don't use a dimmer. The bulb connectors have
proved to be a bit problematical, I found the cables need to come out of
the bulb connector more or less straight up. If the cables are bent at any
sort of angle, the lights don't always come on. Very often, just the action
of removing the bulb retaining ring from the fitting and easing the light
down would make it light, then it would go out again when the bulb was
secured back into the fitting.

I have a bungalow, and dressing the wires into a different position from
the loft rather than trying to bend the wires from below through the
fitting seems to have cured the problem

Most likely the lamp-holder to lamp connections. They run a lot of
current and with a lot of heat. The lamp pins and lamp-holder
connections tend to burn and become high resistance. Look at the lamp
pins, they should be clean and polished, if not fit new lamp holders
and lamp as a pair - they are not expensive.

Err, no. That was the first thing I checked. 30+ years as an electrical
engineer in power distribution has taught me where problems might lay.

What I didn't say, because I didn't think it necessary, I have a spare
fitting and could do a simple jury rig on the bench to reproduce and study
the problem when it first showed up. Poor design of the fitting maybe, as
the contact is a single sprung strip down one side of the socket only. Bend
the wires in the wrong direction and the contact is clear of the lamp pin;
can't see it with the naked eye, but with the wires correctly positioned,
the holder makes good contact with the lamp. Been fine with no overheating
for a couple of years now.

--
The Wanderer

I have seen the truth - it doesn't make sense

On Fri, 22 Jan 2010 19:12:07 -0000, John wrote:

"The Wanderer" wrote in message
...

I have a bungalow, and dressing the wires into a different position from
the loft rather than trying to bend the wires from below through the
fitting seems to have cured the problem


You have a bad connection. You MUST fix it as it is a fire risk.

No, I have a poorly designed lamp connectors, which have now been operating
perfectly satisfactorily for a couple of years since I first diagnosed the
problem. See my reply to Harry Bloomfield.

Granny, eggs, suck, teach don't. Rearrange into a well-known saying! :-)


--
The Wanderer

Usenet is like a troupe of performing elephants with diarrhoea:
massive, difficult to redirect, awe-inspiring, entertaining perhaps,
but a source of mind-boggling amounts of excrement when you least expect
it.

John Rumm wrote:
Dan Gravell wrote:
I have four halogen LV downlighters in my kitchen, controlled by one
dimmer switch. All of them use dimmer transformers. I once had to
change the chocolate box on one of them that melted, but other than
that they have given three years of trouble free operation.

Recently they have been failing to turn on. This affects all of the
lights, not just one. I noticed that if I turned the dimmer down (made
the light more dim) they would then come on, and turning the dimmer
back up would turn them off again.

It's rather intermittent, sometimes they turn on fine at full power,
other times not.

I took a look in the switch unit but all the connections seem fine
there.

Any other ideas?


It sounds like you have several individual transformers - one for each
lamp. Hence the only common point is the switch. So I would suspect that
first.

frankly, its nor clear what you have.
separate dimmers and separate transformers, whether transformers are
electronic of toroidal or indeed anything.

"The Wanderer" wrote in message
...
On Fri, 22 Jan 2010 19:12:07 -0000, John wrote:

"The Wanderer" wrote in message
...

I have a bungalow, and dressing the wires into a different position from
the loft rather than trying to bend the wires from below through the
fitting seems to have cured the problem


You have a bad connection. You MUST fix it as it is a fire risk.

No, I have a poorly designed lamp connectors, which have now been
operating
perfectly satisfactorily for a couple of years since I first diagnosed the
problem. See my reply to Harry Bloomfield.

Granny, eggs, suck, teach don't. Rearrange into a well-known saying! :-)





Poorly designed connections are giving you a bad connection - it still needs
fixing even if you feel it is not your fault!

On Sat, 23 Jan 2010 00:27:07 -0000, John wrote:


Poorly designed connections are giving you a bad connection - it still needs
fixing even if you feel it is not your fault!

You're beginning to annoy me.

They are fixed, by virtue of positioning the wires in such a manner that
the contacts within the socket are now making good and proper connection
with the pins on the lamps, and have been for a couple of years now.

Now be a good little boy and go out and play amongst the traffic.

--
The Wanderer

Better to keep your mouth shut and be thought a fool
Than open it and remove all doubt. (Mark Twain)

On 22 Jan, 17:16, "TMC" wrote:
Replace dimmer with normal switch and see if they work OK

If so replace dimmer switch

Tony

Ok here's what I tried today. They've completely stopped working now.

I didn't explain this before but the dimmer switch is actually on a
dual plate dimmer switch with another dimmer for another set of
lights, which *do* work.

They are slightly different though. Both dimmers have three
connections marked L1, L2 and another symbol which looks like a
switch. On the working set all three are connected. On the faulty set,
only L1 and the switch are connected, there appears to be no wire for
L2.

Despite this, I decided to wire the faulty set into the dimmer switch
used by the working set and just use L1 and the switch on the known-to-
be-working dimmer.

This didn't work. The lights still don't come on. What would be a good
next step?

As an aside, there also appears to be two wires bonded within an
orange sleeve - I'm not sure if this is related to the 'missing' L2
wire on the faulty set.

frankly, its nor clear what you have.
separate dimmers and separate transformers, whether transformers are
electronic of toroidal or indeed anything.

Not sure if this was a reply to me or not... the faulty set has one
switch, four lights, behind each one is a dimmer transformer. I don't
know what toroidal means.

Thanks for your help!

Dan

Dan Gravell wrote:


Not sure if this was a reply to me or not... the faulty set has one
switch, four lights, behind each one is a dimmer transformer. I don't
know what toroidal means.


The point is that inductive wound transformers break dimmers. Toroidal
is a doughnut of iron wound as a transformer. Its less likely to hum
than a standard Es and Is transformer.
So its used.

HOWEVER there is enough leakage inductance to spike MANY dimmers.

electronic transformers may or may not dim successfully at all.

What you need is

- dimmers that are specified for inductive loads, generally 'suitable
for LV lighting'
OR

*electronic* transformers that are specified 'to *work with dimmers*'


Or face the consequences you have. Presumably triacs blown to ****, and
either lights are on full all the time, or wont come on at all.

FIRST step is to say what exact dimmers and transformers you have.

The other possibility, and it happened here, is that you have a goofy
track system, and the contacts to it are corroded up.



Thanks for your help!

Dan

On 24 Jan, 21:24, The Natural Philosopher
wrote:
FIRST step is to say what exact dimmers and transformers you have.

Thanks for your help.

The transformers are Aurora AU-E60 as seen he http://bit.ly/aGykgw
.. The info says "Fully dimmable with resistive and inductive dimmers"

The dimmer switch says the following on:
GET
BS EN60669-2-1
60-250W
200-240W
250W max

The lights are 50W I think, not sure if that causes a problem with the
60-250W statement above.

I have a photo of the switch, wired up, if it helps.

Dan Gravell wrote:
On 24 Jan, 21:24, The Natural Philosopher
wrote:
FIRST step is to say what exact dimmers and transformers you have.

Thanks for your help.

The transformers are Aurora AU-E60 as seen he http://bit.ly/aGykgw
. The info says "Fully dimmable with resistive and inductive dimmers"

OK so they are electronic dimmables. That's one thing out of the way.
The dimmer switch says the following on:
GET
BS EN60669-2-1
60-250W
200-240W
250W max

The lights are 50W I think, not sure if that causes a problem with the
60-250W statement above.


Nope, as ling as a max of 4 auroras per dimmer is adhered to. 400W is
better,but they should work



Now exactly how are they 'not working'

I have a photo of the switch, wired up, if it helps.

Thanks again to both of you.

On 29 Jan, 04:29, The Natural Philosopher
wrote:
Now exactly how are they 'not working'

Well, now they simply don't light up at all when turned on at the
switch. They went through this intermittent phase when sometimes they
wouldn't light up when at the highest setting, and then for a while
they worked if you turned them on at the switch (no light), left them
for a while, and then the light would come on, but now - nothing.

What was it you were saying about the track?

Dan Gravell wrote:
Thanks again to both of you.

On 29 Jan, 04:29, The Natural Philosopher
wrote:
Now exactly how are they 'not working'

Well, now they simply don't light up at all when turned on at the
switch. They went through this intermittent phase when sometimes they
wouldn't light up when at the highest setting, and then for a while
they worked if you turned them on at the switch (no light), left them
for a while, and then the light would come on, but now - nothing.

What was it you were saying about the track?

Well I had some rather crap track lights, where the transformer plugged
into the end.

The plug in bit corroded badly.

try the dimmers out on a meter or on an ordinary bulb.

In article , John
writes

You have a bad connection. You MUST fix it as it is a fire risk.

I have to agree. In the kitchen I have three lamps on flying wires
plugged into a triple-way adapter at the transformer. Two lights are
ok, the third was only coming on whenever it felt like it. Solid
on/off. None of the typical flickering at all. Changed the lamp a
couple of times with no effect.

Physical movement had no effect. In the end I swapped the misbehaving
lamp with its neighbour at the 3-way socket - problem gone. The
plug/sockets are very similar to the ones you see on PC power supplies
at the motherboard end (Molex connectors).

It worries me a bit that the connections on those cheap Chinese made
things can be so ephemeral.

--
(\__/)
(='.'=) Bunny says Windows 7 is Vi$ta reloaded.
(")_(") http://imgs.xkcd.com/comics/windows_7.png

I fixed this today. I took the switch off the wall again and noticed
that one of the wires had actually become very weak. I took the sheath
off it and found it was about to fall apart, and the wire was all
dark. So I clipped it back and rewired. It works now.