The start of an LED build

[Renton777]

Hello Everyone,
I am a long time lurker on the forum, mostly because I have been dreaming of setting up a reef tank, but now that the time approaches in which I have the green light (from the wife) to build it, it is time I start posting!

I am considering building an LED fixture for a 30x30x24 high cube aquarium. After some discussions with knowledgeable people I have come up a plan to use 4 10in x 10in heat sinks. Each heat sink would have the following:

A 4x4 array of 8 neutral white Cree XRE and 8 Cree XP-E royal blue (40 degree optics)

1 Cree CRE – Blue (cool blue) in the middle with 80 degree optic (or would true violet be more beneficial?)

I plan to run all the Blues on one dimmable driver and all the whites on a second dimmable driver. I was thinking of using the Meanwell ELN 60-48D dimmable LED driver but I am unsure if just one can be used for all 28 blue led’s and then a second one to control all 24 white led’s. My question is if that is too many LED’s per driver?

The next question I have is how many power supplies would I need. I was considering the 24V, 6.5A POTRANS POWER SUPPLY http://www.mpja.com/prodinfo.asp?number=16854+PS , but again I was uncertain if that would be enough.

Finally, I have read that the Meanwell ELN 60-48D dimmable LED driver can be used with the Apex controller but I am unclear as to how the connection between the two units is made.

I look forward to any suggestions and answers you may have!
Thanks,
Nathan

[iwishtofish]

A lot of people are DIYing LEDs now...how much do you think all the hardware will end up costing you?

[der_wille_zur_macht]

Originally Posted by Renton777

(or would true violet be more beneficial?)

Very much personal preference. There's maybe $10 at stake here - just get both and try. I can tell you that adding only one of either of those colors is going to have a minimal effect. IMHO you'd be just as well off carefully choosing color bins for the rest of your LEDs as that can make a large difference but is often overlooked.

I plan to run all the Blues on one dimmable driver and all the whites on a second dimmable driver. I was thinking of using the Meanwell ELN 60-48D dimmable LED driver but I am unsure if just one can be used for all 28 blue led’s and then a second one to control all 24 white led’s. My question is if that is too many LED’s per driver?

Typically the ELN 60 48 is used with a single string of 12 LEDs in series. You can probably get away with 13 in series, but 14 would definitely be pushing it with the higher-drop LEDs you're talking about.

The other option is to do two strings in parallel. This effectively doubles the capacity as you can "fit" 24 - 26 LEDs on each. However, parallel strings require some VERY careful setup otherwise you run the risk of damaging the LEDs or building a rig that performs differently from your expectations.

The next question I have is how many power supplies would I need. I was considering the 24V, 6.5A POTRANS POWER SUPPLY http://www.mpja.com/prodinfo.asp?number=16854+PS , but again I was uncertain if that would be enough.

You need zero of these supplies. Meanwells have their own AC-DC circuitry built in. They run off 120v AC from your wall outlet. You don't need a separate supply to power the driver.

However, you DO need to supply a dimming signal - many people do this by rigging a 9 - 10v wall wart. It doesn't need a lot of current capability as it's simply providing a signal, not powering the drivers.

Finally, I have read that the Meanwell ELN 60-48D dimmable LED driver can be used with the Apex controller but I am unclear as to how the connection between the two units is made.

It's simple assuming you have the version or add-on you have can do 10v analog - you just connect the pair of dimming wires from the drivers to the terminals on the controller.

[Johnsy85]

Keep us posted and take pictures!

[truebeliever71]

Typically the ELN 60 48 is used with a single string of 12 LEDs in series. You can probably get away with 13 in series, but 14 would definitely be pushing it with the higher-drop LEDs you're talking about.

The other option is to do two strings in parallel. This effectively doubles the capacity as you can "fit" 24 - 26 LEDs on each. However, parallel strings require some VERY careful setup otherwise you run the risk of damaging the LEDs or building a rig that performs differently from your expectations.

Hey Nate,

Can you elaborate on this? What precautions do we need to watch for?

[1Snapple]

im tagging along to.