Off Topic-replacing Halogen with LED ,electricians???

[PhilipA]

I am currently studying replacing my 12V halogen downlights with LEDs.
I have about 35 in the house.

I have identified my transformaers as ATCO TM50-2 safety isolating Transformers which are stated as suitable to drive low loads such as LEDs.ie not switch mode . They are currently hard wired at 1 transformer per halogen light.

My question is how much more power will I use if I just replace my 20-50W halogens with 2watt LEDs using 1 transformer per light ( as wired now) rather than rewiring the LEDs so That I load a transformer by placing 5-7 LEDs on the one. This is not possible with most as several have just 1 or 2 lights per switch

I did some reading on the net and found that there are two components to transformer losses, the "copper" loss and load loss.

Will the transformer have 75-80% efficiency at 2W ie use say 2.4 watts? or what? This would be acceptable to me as I would not quibble about 0.5 watts.
Alternatively is there any harm done if I route 12v to a number of lights and just leave the unused transformers in place.

I do not need an electrician if I just stay on the 12volt side.

Any and all input appreciated.
Regards Philip A

[keithy47]

Well you are right that there are 2 components in transformer loss. The first the energy used create the magnetising current in the tranformer or "iron" loss and is pretty much constant regardless of load, the 2nd is the energy used relative to the load and are I squared R losses.
So i would think that it would more efficent to run less transformers however with a 50W unit i'd say the magnetising power wouldn't be more than a few watts per unit so im not sure how much you would save.

[rollypolly]

hi.

i am a apprentice electrician in melbourne. You need to be very carefull if you are going to replace your hallogens with LED as most transformers will not work properly with LED bulbs. Search for led and transformers on Google for more info. Also you MEST use a licenced electrictian as you are dealing with AC voltages that will kill you if you touch the wrong thing or at best may only cause your house to burn down!!!!

[PhilipA]

Rollypolly, I have already researched the net , and I have identified my transformers as suitable for low loads. They are wound transformers not electronic which are the ones which will not tolerate low loads. But I am sure you are aware of that seeing you are an apprentice electrician.

There is even an entry from LEDCAP.com.au who are manufacturers and installers of LED commercial lighting who recommend my specific transformers for this purpose.

Electrical_Req (http://www.ledcap.com.au/ElectricalRequirements.htm)

If you read my thread I do not propose to touch any 240V wiring, and I have for many years worked with 12v without a single house or car being burned down.
Regards Philip A

[sydney-web]

We also have ATCO TM50-2 transformers and it is our intent to replace our old halogen bulbs with 6w StarLux LED Downlights from Todae. They offer information on their website with regards to power and cost savings available in opting for Redback and Possum transformers.

Thanks PhilipA for indicating that the ATCO TM50-2 transformers are suitable for low voltage LEDs. My LEDs arrive this week. Fingers crossed they work without any flicker.

Todae indicate that the voltage savings in installing low voltage transformers is roughly $3 per transformer per year so you would need to have a lot of downlights in your house to warrant replacing old transformers with me.

"Replacing normal transformers with possums can save you on average $3 per year per light. So if you have 20 halogens in your house, every year you will save $60 on your energy bill. *Based on an average of 6 hours per day at a cost of 13c/Kwh."

[bee utey]

There are a number of higher power led lamps coming out, I would resist putting in 2W ones. I have a number of cree 5W ones around the house that are reasonable, not excellent, and I am waiting for the 10W ones to come down in price. Another year or so should do it...

Meanwhile there are some good 6W ones available, such as these...

4 X MR16 12V 6W LED Cool White Downlight 400lumens!!! - eBay, Down Lights, Lighting, Fans, Home. (end time 16-Nov-10 10:28:45 AEDST) (http://cgi.ebay.com.au/4-X-MR16-12V-6W-LED-Cool-White-Downlight-400lumens-/330462058883?pt=AU_Lighting_Fans&hash=item4cf112d983)

[VladTepes]

There are a number of higher power led lamps coming out, I would resist putting in 2W ones. I have a number of cree 5W ones around the house that are reasonable, not excellent, and I am waiting for the 10W ones to come down in price. Another year or so should do it...



That's it in a nutshell. The output of the LED lighst currently available for anything resembling a reasonable price (which you would want, given you have so many of the things) will be disappointing as compared to your current halogens.

Even 10W will only bring it to within the realms of useful, in my opinion.

I'd be waiting a while before considering such a move.

[Landy110]

I was in electrical wholesale for 25 years and got out about a year ago but at that time the lighting suppliers that were fair dinkum told us not to bother with LED yet as it wasn't good enough. There was still a lot of development to be done to make them worthwhile. Like I say, that opinion is about a year old but it is worth keeping in mind. Try one of two before committing.

[PhilipA]

I have a couple of 3W ones now that are just satisfactory.

Earlier I bought some 6W ones which burnt out their rectifiers very quickly, so the quality was /is variable. I was able to save one by dismantling it and replacing the rectifier with a resistor to make it DC only and use only for camping.

I think that just now there are some becoming available that are equivalent to a 20watt Halogen at a reasonable price and made in Taiwan. They are currently on ebay and I may but some in the next couple of months.
PS the most recent ones have lasted well so far via the iron core transformers and no discernable flickering .
Regards Philip A

[bee utey]

Your iron core transformers will last forever and probably lose about 2-3 watts each. Not a lot compared to the halogen.

If you dare you can run your own 12 volt circuits to most of the downlights, wire to a deep cycle battery and charger and you have a black-out proof house.:)

Certainly there are some dud lights about but as the price drops they will get more attractive regardless.

[d2dave]

Your iron core transformers will last forever and probably lose about 2-3 watts each. Not a lot compared to the halogen.

If you dare you can run your own 12 volt circuits to most of the downlights, wire to a deep cycle battery and charger and you have a black-out proof house.:)

Certainly there are some dud lights about but as the price drops they will get more attractive regardless.

If you ran a maintainance charger on continously a starting battery should work ok but as I am typing this a better idea just popped into my head.

A deep cycle battery and a couple of solar panels. Free lighting and as you said black out proof, something very handy when living in country Vic.

Dave.

[Vern]

LED's are starting to get better, but still not great, Pierlite have a new range out called Starburst, they do a 12w LED which will be the closest to a 50w dichroic, anything lower than 10w doesn't come close.
By using the LV transformer and not an led driver, the lamp expectancy is not as long, CAN be as little as 25,000hr instead of 50,000hr.
I have over 60LV downlights in my house and as they blow i'l be replacing them with 12w leds, i like the output of the dichroics so am hoping pierlite have come close to it.
Oh and rollypolly, know one likes taking orders from an apprentice, so get back in the corner:p

[blitz]

10 out of 10 for your concerns Rollypolly

In Australia an LV license is required if working above 50VAC or 120 VDC ripple free to 1000VAC, 1500VDC ripple free

Extra low voltage is clasified as anything below 50VAC or 120 VDC and a license is not required.

If your not wiring the primary side of the transformer then you are free to do what you want with a 12V system.

[Tombie]

10 out of 10 for your concerns Rollypolly

In Australia an LV license is required if working above 50VAC or 120 VDC ripple free to 1000VAC, 1500VDC ripple free

Extra low voltage is clasified as anything below 50VAC or 120 VDC and a license is not required.

If your not wiring the primary side of the transformer then you are free to do what you want with a 12V system.

Cheers Blitz...

Up here ELV is the relm of the Instros and the Sparkies refer to them as "Low Voltage Plumbers" :D

[d2dave]

LED's are starting to get better, but still not great, Pierlite have a new range out called Starburst, they do a 12w LED which will be the closest to a 50w dichroic, anything lower than 10w doesn't come close.
By using the LV transformer and not an led driver, the lamp expectancy is not as long, CAN be as little as 25,000hr instead of 50,000hr.
I have over 60LV downlights in my house and as they blow i'l be replacing them with 12w leds, i like the output of the dichroics so am hoping pierlite have come close to it.
Oh and rollypolly, know one likes taking orders from an apprentice, so get back in the corner:p

Damien,
How much do these cost?

Dave.

[Vern]

don't know, haven't priced them yet, if i remember i'll get a price tomorrow, do you want just the globe or the whole kit?

[norton5974]

Well my 2 cent worth. It would take a long time to get your money back when changing over.The older wire transformers used about 50 watts of energy and 50 watts for the light, giving a total of around 100 watts in total per lighting point. So they developed the electronic transformer that used about 8 watts from memory to get your losses down. So if you rip out your existing electronic transformer and put the wire wound type in and LED at each lighting point you are not really gaining any thing. So for halogen and electronic transformer it uses about 58watts per point and for LED and wound transformer would from say 50-60 watts allowing for transformer losses. The wound transformer may use slightly less that the figures above but is it worth it. if you changed one wound transformer to drive a couple of lights it would work out better. Remember when changing the 240volt side of thing you need a sparky, and depending on the setup it could be quite expensive.

[d2dave]

don't know, haven't priced them yet, if i remember i'll get a price tomorrow, do you want just the globe or the whole kit?

Don't know as yet. I am planning to move in a couple of years and would then consider changing lights.

If what Norton 5974 said above is correct it would almost be a waste of time changing although I am entertaining the idea of running them off a battery.

As for the 240 volt side, I have see/used a lot of these transformers which come with a lead and three pin plug attatched and just have to be plugged in, in which case a sparky would not be needed.

Dave.

[sheerluck]

Just to weigh in with my experience here...

About 5 years ago, I bought 2 LED lighting kits consisting of 10 button size (about 30mm) brushed stainless style discs with 4 LEDs set in them, along with a transformer to drive each lot of 10 and the wiring. The transformers are wired into a 1.0mm T&E cable with an in-line light switch and a 3 pin plug.

The lights are set into our 2.1m x 1.5m bed headboard as reading lights, and were bought specifically for their lack of heat and "longevity", which was stated as 100,000 hours.:eek:

However, on average 1 LED per week would fail, and we were backwards and forwards to the supplier having them replaced under warranty. But since we got the last warranty replacement batch 3 years ago, not 1 has failed.
The sole difference? We moved from a 1930s house with a 1930s electricity supply. Apparently these LEDs are very particular about the quality of your supply. How you quantify that, I've no idea as I'm not an electronic or electrical expert.

[rocket scientist]

We live in a totally solar powered house off the grid.
24v 700AH battery bank through 4kw inverter to 240v.

I am running the lights on a separate 12v system.
This consists of just 2 x80 w solar panels and 150AH batteries.

Interior lights are 3w LED lamps.
The LED lamps are from Bright Light Autos, (MR163X1W) and if you buy 10 or more the price comes down to about $27 ea. Remember you should never need to replace them in our lifetime, or at least when you do they will be a lot cheaper. Halogens are not cheap especially the frequency they blow.

I have the lamps on racks consisting of 3 mounts. 3 racks for the lounge room/dining area and I find this more than enough light. 9 in total.
Most of the time if just reading only need 3 on.
Outside I have the 3w lamps but also several of the 15w work lamps (BL-0215 at Superbright $115) A very effective outside light that does not draw much power.
Very happy with the lights. A bit of expense to set up but remember the ongoing cost is zero.:):)

[one_iota]

For what it's worth:

On Edison Bulb's Anniversary, a Lighting Breakthrough (http://news.nationalgeographic.com/news/2010/10/101021-energy-edison-light-bulb-leds/)

[d2dave]

We live in a totally solar powered house off the grid.
24v 700AH battery bank through 4kw inverter to 240v.

I am running the lights on a separate 12v system.
This consists of just 2 x80 w solar panels and 150AH batteries.

Interior lights are 3w LED lamps.
The LED lamps are from Bright Light Autos, (MR163X1W) and if you buy 10 or more the price comes down to about $27 ea. Remember you should never need to replace them in our lifetime, or at least when you do they will be a lot cheaper. Halogens are not cheap especially the frequency they blow.

I have the lamps on racks consisting of 3 mounts. 3 racks for the lounge room/dining area and I find this more than enough light. 9 in total.
Most of the time if just reading only need 3 on.
Outside I have the 3w lamps but also several of the 15w work lamps (BL-0215 at Superbright $115) A very effective outside light that does not draw much power.
Very happy with the lights. A bit of expense to set up but remember the ongoing cost is zero.:):)

Pretty awsome set up by the sounds of it.

As we live reasonably close what's the chances of a look next time I am over your way.

Dave.

[Lionel]

I am currently studying replacing my 12V halogen downlights with LEDs.
I have about 35 in the house.

I have identified my transformaers as ATCO TM50-2 safety isolating Transformers which are stated as suitable to drive low loads such as LEDs.ie not switch mode . They are currently hard wired at 1 transformer per halogen light.

My question is how much more power will I use if I just replace my 20-50W halogens with 2watt LEDs using 1 transformer per light ( as wired now) rather than rewiring the LEDs so That I load a transformer by placing 5-7 LEDs on the one. This is not possible with most as several have just 1 or 2 lights per switch

I did some reading on the net and found that there are two components to transformer losses, the "copper" loss and load loss.

Will the transformer have 75-80% efficiency at 2W ie use say 2.4 watts? or what? This would be acceptable to me as I would not quibble about 0.5 watts.
Alternatively is there any harm done if I route 12v to a number of lights and just leave the unused transformers in place.

I do not need an electrician if I just stay on the 12volt side.

Any and all input appreciated.
Regards Philip A

I'm thinking about a similar exercise. This site has some useful info:
LED Drivers & Dimmers - ECOsparks.com.au (http://www.ecosparks.com.au/index.php?cPath=5)

Using the ATCO trannies should cost an extra 3W per light compared with dedicated LED drivers, according to this site.

The Cree LED 6W are about equivalent to a 20W MR16 halogen, and the light is more focussed than with halogens - so less spread. What I am going to do is to identify areas where less light is acceptable, and use the LED's in these places, particularly if they are on a lot of the time. You may well be able to replace about half your halogens.

Where good light is essential, I am going to use high efficiency halogens (eg. Osram IR) These will give the equivalent of 50W from 35W input. Philips also make these. This will also give a 40% saving in electricity.

LED downlight replacements are not really there yet, but using this approach, one can save a bit on electricity.

Cheers,

Lionel

[isuzurover]

I am currently studying replacing my 12V halogen downlights with LEDs.
I have about 35 in the house.

I have identified my transformaers as ATCO TM50-2 safety isolating Transformers which are stated as suitable to drive low loads such as LEDs.ie not switch mode . They are currently hard wired at 1 transformer per halogen light.

My question is how much more power will I use if I just replace my 20-50W halogens with 2watt LEDs using 1 transformer per light ( as wired now) rather than rewiring the LEDs so That I load a transformer by placing 5-7 LEDs on the one. This is not possible with most as several have just 1 or 2 lights per switch

I did some reading on the net and found that there are two components to transformer losses, the "copper" loss and load loss.

Will the transformer have 75-80% efficiency at 2W ie use say 2.4 watts? or what? This would be acceptable to me as I would not quibble about 0.5 watts.
Alternatively is there any harm done if I route 12v to a number of lights and just leave the unused transformers in place.

I do not need an electrician if I just stay on the 12volt side.

Any and all input appreciated.
Regards Philip A

Just did a few quick measurements for you - this may help (see attached graph)

From this it seems you would be best off minimising the number of transformers.

Note these values are the average of measurements using 2 identical setups.

[Utemad]

Have you considered using the fluro bulb replacements?
We have only got two of these type of lights and they are above the kitchen bench. They are 240v though not 12v.
The packet says they need to be slightly more closely spaced than 12v ones but they are 11w with no transformer. Plus they are much better than the LEDs we tried.

[3-Gees]

Hi all.Ihad 11wat gu10 fluros in kitchen,light was ok but they take ages to warm up so have put them in hallway.now have 4x6watt leds in dining room (warm white,2700k) which replaced 35w dichroics and output is almost equal.Each led is run off a osram "possum" elctronic tranny and draws 9watts per lamp,very happy with them,keen to try 'cree' leds on the site Lionel suggested:),.Using one tranny for multiple lights is frowned upon by elect. authorities ,because if a new home owner changes led's back to halogens there is a risk of fire due to tranny beig overloaded,Iwouldn't do it in a customers house ,but in mine......:cool::wasntme::)

[ACA7]

There are a number of higher power led lamps coming out, I would resist putting in 2W ones. I have a number of cree 5W ones around the house that are reasonable, not excellent, and I am waiting for the 10W ones to come down in price. Another year or so should do it...

Meanwhile there are some good 6W ones available, such as these...

4 X MR16 12V 6W LED Cool White Downlight 400lumens!!! - eBay, Down Lights, Lighting, Fans, Home. (end time 16-Nov-10 10:28:45 AEDST) (http://cgi.ebay.com.au/4-X-MR16-12V-6W-LED-Cool-White-Downlight-400lumens-/330462058883?pt=AU_Lighting_Fans&hash=item4cf112d983)

Hi guys,

As Bee-utey pointed out, I'm considering getting these 6W LEDs installed. They will go to my Rumpus Room (6 LEDs), Living (4), Dining (4) & Kitchen (3) areas and the hallway (3) in my new house currently under construction. In all there will be 20 LEDs required and with the eBay prices it doesn't seem to cost an unaffordable amount of money (i.e. hundreds instead of thousands of dollars). However I'm really having a difficult time finding our what transformers to use with these.

There will be at most 6 x 6W LEDs per light switch so the ATCO iron core transformers should work (also the eBay seller suggested so). I could probably get away with about 5 transformers by installing 1 per switch but I'm worried about the energy loss due to their inefficiency and the fact that they will not maximise the life of the LEDs. The lighting lady at Bunnings said the iron core transformers could use up to 35W just themselves to function so that seems to me that a lot my savings will be taken back by the transformer. The Redback and Possum electronic transformers mentioned in this thread has a minimum load of 20W which worries me with setups with 3 x 6W LEDs that I will have in the Kitchen and hallway and also with the dimmer switch in the Rumpus and Living areas.

Does anyone know any alternative dimmable LED transformers that can be hooked up with between 3 to 6 x 6W LEDs each? Would really appreciate some guidance and suggestions here.

Thanks.

[3-Gees]

Hi ACA7,as I posted,I'm using Atco "possum" electronic trannies on my led's (rated at 60 watt) and they work fine,you could easily run 6 leds off one of these with no problems.I'm running one per lamp as the wiring was allready there,also they are much more efficient than iron core trannies,you'll just have to check the specks on the leds ,but most new ones are suitable for elect trannies.:).Try to stay away from chinese made trannies as I had lots of failures on a big job a while ago with these(owner supplied them:(),Cheers,Gregg:cool:

[3-Gees]

Forgot to mention:angel:,these trannies are 'switch start',meaning they need to see a load before they turn on, which was a problem with earlier leds ,but as I said the newer leds don't have this issue,so you should be ok,just get your sparky to check them before hand:eek:

[isuzurover]

Hi guys,

As Bee-utey pointed out, I'm considering getting these 6W LEDs installed. They will go to my Rumpus Room (6 LEDs), Living (4), Dining (4) & Kitchen (3) areas and the hallway (3) in my new house currently under construction. In all there will be 20 LEDs required and with the eBay prices it doesn't seem to cost an unaffordable amount of money (i.e. hundreds instead of thousands of dollars). However I'm really having a difficult time finding our what transformers to use with these.

There will be at most 6 x 6W LEDs per light switch so the ATCO iron core transformers should work (also the eBay seller suggested so). I could probably get away with about 5 transformers by installing 1 per switch but I'm worried about the energy loss due to their inefficiency and the fact that they will not maximise the life of the LEDs. The lighting lady at Bunnings said the iron core transformers could use up to 35W just themselves to function so that seems to me that a lot my savings will be taken back by the transformer. The Redback and Possum electronic transformers mentioned in this thread has a minimum load of 20W which worries me with setups with 3 x 6W LEDs that I will have in the Kitchen and hallway and also with the dimmer switch in the Rumpus and Living areas.

Does anyone know any alternative dimmable LED transformers that can be hooked up with between 3 to 6 x 6W LEDs each? Would really appreciate some guidance and suggestions here.

Thanks.

Did you look at the pdf I posted above???

The transformer I have here would use close to 30W powering 1x 3W light, but decrease to ~10W when it is at maximum capacity (150W in this case). So in order to minimise energy use you should look for 50W transformers - or less if they are available - since you said you will only load them up to 36W.

[bee utey]

Hi guys,
The lighting lady at Bunnings said the iron core transformers could use up to 35W just themselves to function so that seems to me that a lot my savings will be taken back by the transformer.
Thanks.

What a load of... they are feeding you! I plugged a selection of transformer based power supplies into my power meter and get a reading of around 4-5 watts for a 4 amp DC supply. My biggest transformer is a 26.6 amp 320W 12V AC halogen transformer and it draws a measly 8 watts at idle. 35 watts would crinkle the paint off a little transformer in no time. 2-3 watts as I said earlier is more realistic for a 60W AC lighting transformer.

PS my desktop computer plugged into the power meter draws 156 watts. Makes lighting transformers look very good...

Try putting a 35W light globe in a small tin box and see how hot that is, the transformer would hardly get up 10 deg C without a load on.

PPS my power meter reads my desk lamp correctly so it's not wildly out either.

[JA1969]

Hi Mr whippy,

I'm a sparky and last time I visited my electrical wholesaler he showed me the Pierlite 12W LED downlights. I must admit the lux (light intensity) is equivalent to the 50W dicroics that everybody is used to. They put out great light. The trade price he quoted me was $109 + GST. They are marketed for the commercial market at the moment but will come down in price for sure soon. If you do change your original down lights to LED's I wouldn't be looking at anything under 12W.

Jim

[isuzurover]

What a load of... they are feeding you! I plugged a selection of transformer based power supplies into my power meter and get a reading of around 4-5 watts for a 4 amp DC supply. My biggest transformer is a 26.6 amp 320W 12V AC halogen transformer and it draws a measly 8 watts at idle. 35 watts would crinkle the paint off a little transformer in no time. 2-3 watts as I said earlier is more realistic for a 60W AC lighting transformer.

PS my desktop computer plugged into the power meter draws 156 watts. Makes lighting transformers look very good...

Try putting a 35W light globe in a small tin box and see how hot that is, the transformer would hardly get up 10 deg C without a load on.

PPS my power meter reads my desk lamp correctly so it's not wildly out either.

She's not that far off. Everyone seems to have missed the file I uploaded on the previous page, so here it is again.

[bee utey]

She's not that far off. Everyone seems to have missed the file I uploaded on the previous page, so here it is again.

Your PDF is quite correct for a fully loaded transformer, yes I did see it. However this consumption consists of two components, namely the zero-output-current loss (which I measured directly) and the resistive loss under load. It will be approximately linear with increasing load until you get closer to magnetic saturation in the transformer cores, ie overload.

The point to be made is that a 3W-10W LED will cause much less transformer loss than a 50W halogen. It will be closer to the unloaded loss than the full load loss. To settle the question accurately you need to plug the led/s and transformer into the power meter, then work out whether the loss is greater for many low load trannies or one fully loaded. I would be surprised if there was a huge difference. If I had a bunch of these I would do it myself but I only have a couple of the monster ones.