Transformer failure

[tpv01]

Hi.

I have a fancy looking halogen light in my kitchen. It was in the house when I moved in so minimum 5 years old. Tends to get a couple of hours use most evenings.

Recently there have been times when it has cut out and needed some time switched off before it worked again. This has been happening more frequently recently and now the light dims before it goes off or goes off after only 10mins or so.

I took it down today and found the transformer and look like I can buy a spare on the internet. Is this the most likely culprit? The light is on the downstairs light ring and the other lights are ok and there is not a dimmer switch so the setup of the light seems straightforward.

//www.diynot.com/network/tpv01/albums/

 

[deadshort]

Hi, is this light on a dimmer switch ?

DS

 

[RF Lighting]

What's the output rating of the transformer? Have you fitted the correct wattage lamps when you have replaced blown ones?

 

[tpv01]

It is not on a dimmer.

I have checked each of the 20 bulbs. The rating seems to be 12V 10w. I found one bulb that was 12v 25W so removed that. The others I am confident are 10W from what writing remains.

Putting the light back on it still seems more dim than it should be so i have switched it off for now in case of further damage.

Is it time to replace the transformer? I have read on this forum that this Eaglerise brand is not thought to be that great. Do i have any other option than a like for like replacement? The size and shape seem quite specific to fit into the light fitting?

 

[tpv01]

these are the photos i took:

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• tpv01
• 2 Nov 2014
• 1

Untitled

• tpv01
• 2 Nov 2014
• 1

 

[JohnW2]

these are the photos i took:

A 210 VA (call it 210 W) electronic transformer is pretty marginal for 20 x 10W lamps/bulbs (and was a bit overloaded when there was at least one 25W one amongst them), so that device has probably been under a degree of 'stress', which could possible have resulted in its ultimate demise. I'm not sure if it has been mentioned, but 'loose connections' somewhere are another possibility.

Kind Regards, John

 

[winston1]

Hi.

I have a fancy looking halogen light in my kitchen. It was in the house when I moved in so minimum 5 years old. Tends to get a couple of hours use most evenings.

Recently there have been times when it has cut out and needed some time switched off before it worked again. This has been happening more frequently recently and now the light dims before it goes off or goes off after only 10mins or so.

I took it down today and found the transformer and look like I can buy a spare on the internet. Is this the most likely culprit? The light is on the downstairs light ring and the other lights are ok and there is not a dimmer switch so the setup of the light seems straightforward.

//www.diynot.com/network/tpv01/albums/[/QUOTE]

That is NOT a transformer. It is a SMPS. Long thread on this subject here:

//www.diynot.com/diy/threads/electrician-expert-statement-recessed-light-transformers.416689/

Read it. Suggest you replace the SMPS with a 200VA transformer for reliability.

 

[JohnW2]

Read it. Suggest you replace the SMPS with a 200VA transformer for reliability.

Admittedly a real (wire-wound) transformer is likely to be far more tolerant than an 'electronic' one (i.e. SMPS), but would you still not be more comfortable with something a bit bigger than a 200 VA one for a 200 W load?

Kind Regards, John

 

[333rocky333]

. Suggest you replace the SMPS with a 200VA transformer for reliability.

My freind has similar can you provide a part number please so if hers fails i can replace it, please

 

[winston1]

Read it. Suggest you replace the SMPS with a 200VA transformer for reliability.

Admittedly a real (wire-wound) transformer is likely to be far more tolerant than an 'electronic' one (i.e. SMPS), but would you still not be more comfortable with something a bit bigger than a 200 VA one for a 200 W load?

Kind Regards, John

Halogen bulbs are quite fussy about over volting and real transformers have poorer regulation than SMPS. It was always recommended that they be run at full load and blown lamps replaced quickly for this reason.

 

[JohnW2]

Halogen bulbs are quite fussy about over volting and real transformers have poorer regulation than SMPS. It was always recommended that they be run at full load and blown lamps replaced quickly for this reason.

Interesting. How voltage-fussy are the halogens? I've just looked up a few, 'real' (toroidal) 12V transformers and good 300 VA - 400 VA ones seem to have a no-load output voltage of only around 12.6 - 12.8V or so, and with partial loading the voltage would presumably be even closer to 12V than that.

If (as was the case with most of the ones I looked at) the spec is given for 230V input, and 12V output at full load, then someone with a 253V supply would presumably be getting about 13.2V at full load. Is it therefore undesirable to have ELV halogens run from a wire-wound transformer if one's supply voltage is usually fairly high?

Kind Regards, John

 

[333rocky333]

Sure this was discussed recently
In the 80' when they came out 12 volt 50mm and 35mm lamps were used widely in retail, the short lamplife became widely blamed on the excessive voltage from the torroidals and it wernt uncommon to read in excess of 13 volts, however i dont think they were branded as 12 volt anyway, i think they were labeled 13.8 even though the lamps were branded as 12 volt

 

[winston1]

Halogen bulbs are quite fussy about over volting and real transformers have poorer regulation than SMPS. It was always recommended that they be run at full load and blown lamps replaced quickly for this reason.

Interesting. How voltage-fussy are the halogens? I've just looked up a few, 'real' (toroidal) 12V transformers and good 300 VA - 400 VA ones seem to have a no-load output voltage of only around 12.6 - 12.8V or so, and with partial loading the voltage would presumably be even closer to 12V than that.

If (as was the case with most of the ones I looked at) the spec is given for 230V input, and 12V output at full load, then someone with a 253V supply would presumably be getting about 13.2V at full load. Is it therefore undesirable to have ELV halogens run from a wire-wound transformer if one's supply voltage is usually fairly high?

Kind Regards, John

The SMPTs usually quote an effective output of 11.8v. I remember reading years ago (10?) about running transformers at full load but I must admit I've not done any tests. Halogens do run very hot however so it makes sense that they are voltage sensitive.

 

[ban-all-sheds]

A 210 VA (call it 210 W) electronic transformer is pretty marginal for 20 x 10W lamps/bulbs (and was a bit overloaded when there was at least one 25W one amongst them), so that device has probably been under a degree of 'stress', which could possible have resulted in its ultimate demise.

And being made by Eaglerise won't help.

 

[JohnW2]

Sure this was discussed recently ... In the 80' when they came out 12 volt 50mm and 35mm lamps were used widely in retail, the short lamplife became widely blamed on the excessive voltage from the torroidals and it wernt uncommon to read in excess of 13 volts, however i dont think they were branded as 12 volt anyway, i think they were labeled 13.8 even though the lamps were branded as 12 volt

AFAIAA, there have always been a lot of "13.8V" ones around, but they were presumably never labelled 12V (and should not really have been recommended for running 12V bulbs/lamps!).

Kind Regards, John