Cree xpg LED setup Help Please!

[Machupicchu]

I need some help figuring out what i need to run some LEDs on my nano.

I was planning on using 9 cool white Cree XP-G high powered Emitters http://ledsupply.com/creexpg-w139.php
to power my 12gal nano w/ 2 24watt dual actinic PCs.

So each one of these things uses about 3.52 (lets say 3.6 to be safe)volts when ran at a max amperage of 1500mA. (yeah thats~450 lumens per Emitter :wink:) So thats a total of 32.4 volts and ~ 48watts.

Pleeeeease correct me if im wrong im not an electrician and iv never worked with LEDs. :hmm4:

Soo, now what i need to know is what to do in between the power outlet and the LEDs themselves. I think what i need (and again please correct me if im wrong thats what im here for) is a driver, or two, that will run 1500mA (or at least >1200mA), at more then 32 volts, with ~60 watts or more of power?

Again i dont know how this works so any input helps. Iv heard of people using something called buckpucks but i think they only run at 1000mA.

I Also wouldnt mind getting two drivers if it makes it easier, as i could control the lighting better with timers. I dont care about dimming so i dont think i need a regulator, unless there is some way i could hook it up to my reefkeeper lite to control dimming?

Anything helps thanks guys.

[westmoorenerd]

One MeanWell ELN-60-48 driver can drive your 9 LEDs at 1.3A...Also the D series is easily controllable with a 1-10v dimmer signal.

[der_wille_zur_macht]

Soo, now what i need to know is what to do in between the power outlet and the LEDs themselves. I think what i need (and again please correct me if im wrong thats what im here for) is a driver, or two, that will run 1500mA (or at least >1200mA), at more then 32 volts, with ~60 watts or more of power?

You are more or less correct. The wall outlet is providing 120v AC. Your LEDs need low-voltage, constant-current DC power. So, you technically need three "features" between the wall and the LEDs:

1) A rectifier to convert AC to DC
2) A transformer to step the voltage down
3) A constant current regulator to correctly drive the LEDs

The good news is, these three functions are available in a single unit - the Meanwell ELN drivers the other poster mentioned.

An alternate route is to use a DC driver, like a buckpuck, which separates function #3 from the first two - so, you still need an AC-DC power supply with the correct output voltage for the buckpuck. FWIW buckpucks are available at 350mA, 700mA, and 1000mA, and are dimmable, so you can pick any current lower than those numbers that you want.

Again i dont know how this works so any input helps. Iv heard of people using something called buckpucks but i think they only run at 1000mA.

The 1000mA max for a buckpuck isn't a bad thing. Keep in mind that the 1500mA "rating" on the XP-Gs is a MAXIMUM, not a TARGET. In other words, it's perfectly acceptable (and often times desirable) to run BELOW that current limit. Running at a lower current is more efficient - more of the electrical power consumed by the LED is turned into light - though, of course, the absolute output is lower. Another advantage is lower heat, both in the absolute and relative sense. This makes thermal management easier, and extends the life of the LEDs. Hence, many people choose to run XP-Gs at 1000mA or even 700mA.

I Also wouldnt mind getting two drivers if it makes it easier, as i could control the lighting better with timers. I dont care about dimming so i dont think i need a regulator, unless there is some way i could hook it up to my reefkeeper lite to control dimming?

Anything helps thanks guys.

The number of drivers will basically dictate the "groups" of LEDs you can control together. In your configuration, you don't NEED multiple drivers.

As far as I know, the RKL has an optional add-on module that can produce a 0-10v dimming signal. This signal would be able to control a Meanwell ELN60-48D.

[Soundwave]

I just built a fixture for my 24G aquapod using 12 of the XP-G and 12 of the XP-E units. I used the good old 1000mA dimmable buckpucks and 24V power supplies. Works like a charm and is very very very bright.

[Machupicchu]

Wow thanks for all the info!:spin3:
And yes i saw your thread and it convinced me to do this haha.

It looks like iv found my driver is the

Thanks Wille for all the technical info, i was having a little trouble wrapping my head around it.

1300mA sound fine especially if they run cooler. i Dont have any room for heat sinks but i have made some cuts into my hood so a fan blows through very nicely.

They will be placed about 3-4 inches apart from each other with the fan blowing...will this be cool enough?

I really want to get into SPS. Is 9 of these things at 1300mA over a 12gal gonna be enough?

The next set of info i need is wiring.

Iv been doing some research (soundwaves thread) and it looks like i just need to wire it in a circuit from the negative on the driver to positive end of the first LED and then negative to positive and so on until the negative of the last LED back into the positive of the driver?

Or will this burn my house down?:lmao:

[Machupicchu]

Also, wats the cheapest place to get all this stuff? if you know of any

[der_wille_zur_macht]

1300mA sound fine especially if they run cooler. i Dont have any room for heat sinks but i have made some cuts into my hood so a fan blows through very nicely.



1300mA is probably OK, and within the max specification, but still higher than the vast majority of builds. I would suggest running at 1A and using more LEDs if you need more power. Your current plan of 9 LEDs means you'll be "wasting" some of the capacity of the Meanwell driver, which can power 12 or 13 LEDs. So you might as well spend the extra $15 - $20 on a few more LEDs and run at a lower current.

They will be placed about 3-4 inches apart from each other with the fan blowing...will this be cool enough?

Hard to predict. Try it and see.

I really want to get into SPS. Is 9 of these things at 1300mA over a 12gal gonna be enough?

IMHO, PLENTY especially if you're using other lighting for actinic supplementation.

Iv been doing some research (soundwaves thread) and it looks like i just need to wire it in a circuit from the negative on the driver to positive end of the first LED and then negative to positive and so on until the negative of the last LED back into the positive of the driver?

Or will this burn my house down?:lmao:

You've got the right idea, but you are describing the first connection backwards. You want the LEDs in series. So, the + lead from the driver goes to the + on the first LED. The - from the first LED goes to the + on the second LED, and so on. The - from the last LED goes to the - on the driver.

[stugray]

DWZM,

I amazed you missed the "i Dont have any room for heat sinks but i have made some cuts into my hood so a fan blows through very nicely."

Machupicchu,

You MUST use SOME sort of heatsink, especially running above 1.0A.

They will only last about 20 minutes at that current setting with no heatsink.

Stu

[der_wille_zur_macht]

EEK! I agree 110%. Thermal management is extremely important. You need a fair amount of mass attached to the star (a heatsink) and in most cases also a fan blowing on the heatsink. I'd be shocked if you even got 20 minutes from an XP-G at 1.3A with no heatsink.

[iNeedaFix]

A heatsink is a must even running them at 700ma they won't last long but at 1300ma the glass from the led will come off and the led will fail within an hour 20-40 min would be my guess. As the poster above said get a heatsink and also just get the 3 extra LED's and run them at a lower current get the meanwell ELN-60-48d and you can balance out color with the atinics. In fact I would just ditch the atinics and get royal blue LED's to supplement since from what I seen royal blues give a better pop to corals than most atinics.

[Machupicchu]

wow thank you again for all of the quick info.

Crap looks like ill be tearing this hood apart a lot more than i wanted to:worried:

Any ideas on installing a heatsink in this tight of a place? I was thinking if a could do a high mass bar across each row of three could this be enough heat dispersion. Also is there a type of glue that will allow the heat to transfer to a bar better than say super glue. Or should i just screw them in.

I was hopping i could stay away from the sinks with all of the ridges in the top to save space. Its in the hood of a 12gal jbj.

[Machupicchu]

Is aluminum the best way to go?

http://ledsupply.com/led-heatsink.php

[stugray]

I use the 1"x1" Al. channel just like on that page, but $7/ft. is highway robbery.

I can get it locally for less than $2/ft.

Check your local metal supply places.

Stu

[Machupicchu]

Well i think my addiction has hit an all time high.

Turns out there is absolutely no room in that hood.

Im now thinking about making a pendent, which will essentially be a big heat-sink similar to this http://reefcentral.com/forums/showthread.php?s=&threadid=1658978But a little smaller scale.

I would remove the hood completely
and maybe get one of these http://www.jbjnanocube.com/contents/en-us/p10926.html i could prbly get it made for cheaper.

Still planning on using the same LED setup, and removing the PCs from the hood and using them as Actinic.

I see more and more people doing topless tanks but im worried ill get alot of crap falling onto the water surface(Am i being paranoid?) Yet iv heard that glass can block out a lot of useful light.

Also if anyone knows where to get a heatsink likr the one he used that would be awesome

[reefkeeper78]

here is a link from the local club in my area. this guy built a led fixture for his 90g. I've seen this in person and its very impressive. when i have the money, i'm going to do the same for mine. http://saltwatervt.org/forums/viewtopic.php?f=25&t=1455

[Machupicchu]

anyone know where i can get my hands on a 10x14 inch heat sink?