Downlighters problema

[breen77]

Can someone help.

I have many downlighters installed throughout my house as I built it not physically but from scratch.

The problem with the downlighters is that a few have blown but when I replace the bulb it does not work??? Would there be anything wrong with the downlighters??

The next stage is to try and disconnect one that works and see if that proves anything.

Does anyone have any ideas or ever come across this?

 

[sparkybird]

if they are 12V lamps (bulbs) then it's probably the transformers that need replaceing

 

[breen77]

if they are 12V lamps (bulbs) then it's probably the transformers that need replaceing

Why would this be? The lights are in hall and landing so never constantly on just switched on and off. The never stay on for long periods.

Which part is the transformer? Is that the white box that the mains cable connects to?

Where can I get them? How long should they last?

 

[STI]

When you replaced the bulbs what were the pins like, very thin or like a rounded t shape.
If thin then v likely to be a 12v. The transformer is usually an oblong box with writing on it stating its power rating amongst other things.
Why do they blow , because they can. Often you can find where they connect to the light fitting the terminal box has overheated, usually due to a poorly made connection.

 

[breen77]

When you replaced the bulbs what were the pins like, very thin or like a rounded t shape.
If thin then v likely to be a 12v. The transformer is usually an oblong box with writing on it stating its power rating amongst other things.
Why do they blow , because they can. Often you can find where they connect to the light fitting the terminal box has overheated, usually due to a poorly made connection.

Yes they are small thin pins.

Yeah know the transformer box now how do I make it a better connection? Where can I get replacements?

It doesn't mater how long they are switched on for they can still overheat?? Can I replace them with the rounded T shape connectors?

 

[sparkybird]

12V transformers here

http://www.tlc-direct.co.uk/Products/LTYT50.html


You may be able to change them to GU10's (mains halogens - I'm guessing this is what you mean?) - but you will need to be able to by pass the transformers and it will depend on the type of light fitting you have - mains tend to require an earth.....

 

[breen77]

Will probably keep the type I have.

So I can just replace the transformers and all should work again? Will order 1 to test.

What should be the life span of the transformers?

 

[Taylortwocities]

What should be the life span of the transformers?

Untitled

• Taylortwocities
• 2 Jan 2010
• 22

They are electronic items. They can last 10 years, they can last 10 minutes.
Cheap is never the best plan/


Back in the good old days each room had one light bulb.

If a bulb went every 2-3 months you didnt think about it as you only have perhaps 8 lamps for the whole house.

Now you have maybe 12 lamps in a single room and, even with a modest failure rate it will seem to you that the lamps keep blowing all the time.

That will serve you right for contributing to global warming by using 300watts of energy to light a room that can adequately be lit by a single 60 watt old style light bulb. (Or even better a single 11watt energy saving lamp).

 

[Monkeh]

That will serve you right for contributing to global warming by using 300watts of energy to light a room that can adequately be lit by a single 60 watt old style light bulb. (Or even better a single 11watt energy saving lamp).

An 11W CFL isn't adequate to light my loo, let alone any inhabited room.

 

[ericmark]

I was pleasantly surprised when I tried some of the LED lamps. Far better than expected. With the folded or coiled compact design of florescent or cold cathode lamps there is a huge difference between the designs. Where the control gear is separate from the tube high frequency inverters can be used to control the lamps which in turn means they are far more efficient and the tubes last longer. So a 22W 2D ceiling lamp with an electronic starter (HF) will in general give out far more light than a 22W CFL where the control gear is built into the lamp.

As far as the 50mm spot lights go there are two main types the 230v GU10 which will allow swapping between CFU (Cold Cathode), LED, and Quartz Tungsten with ease and the extra low voltage type which are sub divided into two main types.

The old types used a transformer and one can swap the lamps to LED from Quartz Tungsten without any real problem but the whole idea of the low voltage was to maintain the lamp at a very controlled temperature. Two hot they burn out and also too cold and the tungsten is deposited on the quartz and again they burn out so today simple transformers are no longer used instead an electronic switched mode power supply is used. These often called transformers have a minimum output as well as maximum and so you can't swap to LED without also changing the transformer.

The extra low voltage (12v) also have a problem with the pins where the holders over heat and contact with the pins is lost. Unlike the low voltage (230v) GU10 and GZ10 where the dichroic lamp will only fit the GZ10 type with the extra low voltage MR16 the dichroic lamp can be fitted in error to the fittings where there is no allowance made for the extra heat at the back of the lamp. As a result they over heat.

When any tungsten lamp blows one can get ionisation as it blows and there should be a built in fuse however this is not always the case and the cheaper inverters and dimming switched can fail as the lamp blows if there is no protection built in.

Quartz lamps should not be dimmed although there are dimming units that will work with them. This is because the temperature is so important to give long life. However there is often no warning about dimmers shorting the life on the dimming switches. With non quartz they in fact can increase the bulb life.

Today with the better LED and Cold Cathode spot lamps there is really no reason except maybe in the bathroom for using the extra low voltage lamps. However our rules since the 1960's require earths to be taken to the light fitting even if not used. This means changing from ELV to LV can also mean changing cables. Or using double insulated units and turning a blind eye to the rule on earth wires.

There are alternative units to replace the low voltage inverters that will work with LED lamps but it does in the main mean you can't return to using quartz halogen tungsten lamps.

One other problem with the ELV is lamps come from 10W to 50W with the same connections so where designed for 10W it is easy to overload the inverter and where designed for 50W you can under load the inverter.

With both MR16 and GU10 there are many angles of lamp again so easy to get a lamp which will physical fit but does not do the job as the angle is wrong. They are spot lights and work well as bed side lamps or lighting pictures on the wall but as general lighting they need to have the light reflected off a white surface so changing the wall paper to a pattern can result in a very dark room looking more like a planetarium.

 

[ban-all-sheds]

I have many downlighters installed throughout my house as I built it not physically but from scratch.

Shame you didn't get somebody who knew what they were doing to design the lighting for you.

 

[djt205]

@BAS I always think of you when I see these things... you are spot on (get it)