Dichroic lamps

[Mo]

We recently had 18 dichroic lights put into our kitchen ceiling and there are only about 5 working now. The lamps were put in at Christmas and because of the horrendous cost I replaced only two, a week ago and one of them has gone already.

They are 50w but the 240v variety. There is a large gap above the ceiling but do you think it could be possible that it is just getting too hot in there and that is the reason they keep dying on me.

I thought it was because there had been a leak from the shower above and the foil backed plasterboard ceiling was slightly damp and I thought maybe the wiring had gone rusty but then I suppose they wouldnt work when the lamps were changed if that was the problem.

As you can see, electric lights are not my strong point!!!!!

Any help would be appreciated.

 

[Inspector]

Do you see them blow or did they fail to illuminate when you swith the power on?

Over heating can make them blow, but vibration (from someone walking on the above floor) or the lamps cooling down too quickly can also be a cause. If the lamps are recessed in the ceiling then you should consider boxing them in within the ceiling void (but so close to cause overheating).

 

[Mo]

Hi Inspector, sometimes they just don't switch on but occasionally we hear one 'ping' when we switch them on.

I don't think it will be vibration as there is only a study above and a bathroom. The ceiling is a false one so the original ceiling is above it and I would assume that this would help absorb any vibrations.

 

[securespark]

Are they a reliable brand?

Is your voltage too high? This can shorten lamp life.

If the brand is iffy or unbranded, try buying one or two good quality ones, fit them, and see how you go.

 

[Big_Spark]

Let me give you an example.

Next door neighbour, had 14of 12V hologens installed in kitchen / diner 9 months ago.

Transformers are wire wound not electronic, lamps are all Osram. So far no lamp has been changed.

How do I know, I installed them and Andy is a record producer, would not know how to change a lamp whit dot to dot intructions, so he knocks on my door.


It is like anything, the voracity of any installation is only as good as the components making up that installation.

 

[Mo]

The holders are Alto and they came with lamps, don't know the make of the lamps and its a bit late to go climbing about in the kitchen to take one out of the holder. I will check in the morning. But the two new ones I put in are Phillips guaranteed to last 1 year and they lasted about a week.

 

[Big_Spark]

The holders are Alto and they came with lamps, don't know the make of the lamps and its a bit late to go climbing about in the kitchen to take one out of the holder. I will check in the morning. But the two new ones I put in are Phillips guaranteed to last 1 year and they lasted about a week.

Alto are poo, they are cheap and nasty WF own brand rubbish.

If you want quality lights that don't break the bank, try JCC

And you won't go wrong with Osram lights and wire wound transformers

 

[securespark]

Agree with you, FWL, wirewound are brill. But have also used Osram Halotronic (mouse) tx's to great effect.

 

[Mo]

Oh dear! Cheap and nasty! I had just replaced all the low voltage ones because they kept going with these Alto 240V ones. Someone recommended that we put 240V in instead and they would be better. Didn't work though. These ones don't have transformers.

Have just checked the bulbs and they are all Phillips - are they no good?

Have just been thinking about my original post and as there are only 4 working now, out of 18, I don't suppose it is too hot above the ceiling any more and they are still blowing.

Any more ideas anybody?

 

[bignev]

Guys

i'm just about to install halogen lighting into a bedroom. I've read several articles in this form and elsewhere. What are he pros and cons of low voltage and mains. It would seem that low voltage bulbs last longer. What exactly is a soft start and is this advisable. The bedroom is 8mx5m and has a en-suite in one corner. I was thinking of splitting the room into two zones so each area could be controlled separatly by a dimmer and then the en-suite seperatly. How many lamps would you suggest. I was thinking 10-12.

FWL, great link, which lamps did you use in the installation you mentioned.

 

[Stod]

What exactly is a soft start and is this advisable.

Stops the current surge when you switch on.

The resistance of the filament is much lower when cold and increases when hot. So the current is much higher than the lamp rating for the first few milliseconds after switching on. Soft start reduces the average current for these first few mS.