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

Originally Posted by 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.

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.

Originally Posted by 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

I'm thinking about a similar exercise. This site has some useful info:
LED Drivers & Dimmers - ECOsparks.com.au

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

Originally Posted by 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

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.

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.

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......

Originally Posted by 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)

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.

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

Forgot to mention,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