Some LED Help

[longimanus]

Hi

Got some help from you with regards to meanwells and my LED's, but need some further help going forward please.

I have decided on doing a complete strip for my tank, this way I can add another strip when I have the time and money.

I have drilled and tapped my holes ready to attach my LED's, all 36 of them (12 XPG White, 24 XPE Blue)

I have read your notes on LED building and it says to use 18-6 AWG wire, what would be best for me to use to connect the LED's?

Should I use a different type wire to connect to the meanwell???

Can I mount the meanwell in the sump? Is there a minimum distance this can be away?

Many thanks

[evilc66]

Chosing the right wire is all dependant on the distances involved. For LED to LED wiring, 26-18awg is fine. Anything bigger than that and it starts becoming hard to work with. For LED to driver connections, you can use the same wire gauge if the distances are fairly short, like less than 6ft. With you wanting to put drivers in the sump area, something 18-16awg should be used to reduce the voltage drop associated with long wires.

[longimanus]

Evil

Many thanks for the info on this, it is much appreciated.

I am sure that I am going to pick your brains a bit later in the build
:thumbsup:

[evilc66]

I'll be around :)

[longimanus]

Hi Evil

After a hols and lots of other tank chores I have managed to get some time for the LED build.

I have tapped my heatsink and attached my LED's.

I have a query on the artic silver that I used between the LED and the heatsink, some of this has come through a small hole in the star, I tried to remove as much as possible, but some is smeared on the contacts. is this ok, if not, whats the best way to remove?

Also, with regards to my optics, I have carclo ones, what glue is best to attach then to the fixture?

Many thanks

[evilc66]

You can use almost any solvent cleaner to remove the thermal compound. Some work faster than others. Denatured alcohol works ok, as does acetone. MEK is my personal favorite. Takes it off much quicker, but it's a little more stinky. Apply any solvent with a cotton swap. Avoid getting solvents on the LED at all costs. I would remove the star completely and clean all excess thermal paste off before going further. The stuff is electrically conductive, so it could cause some hard to find shorts when you go to power it up.

For attaching the optics, use a little dab of clear silicone. Never use super glue, as it will fog the lens and the dome on the LED.

[longimanus]

Hi, good info on the optics attachment, didnt think of that.

With regards to cleaning, I would like to clarify something. Are you saying take the star off and just clean the star, leaving the paste on the heatsink? If so will the paste still be ok?

Still new to this so please bear with me

[XSiVE]

you will want to fully clean both surfaces.

[longimanus]

you will want to fully clean both surfaces.

That then means I will have to apply the compound again and I will experience exactly the same problem.

Sorry, I am a bit confused here?!?!?!?!?!

[XSiVE]

Use a little less compound this time, it should be fine.

[longimanus]

Hi

Almost done the LED's, now thinking about the drivers.

Is it possible to house them in their own plastic box? I want to make it all organised with all the drivers in the box. the thing I was worried about was the heat of the drivers, will they be ok?

Cheers

[evilc66]

If the box is fairly small, then you will want to vent the top at the very least to help remove hot air. If you are using a larger box with more interior room than you actually need, then you can get away with keeping it sealed.

[longimanus]

The box is 250 x 200 x 60 mm, I think I will vent as well just to be sure

Thanks for the info

[longimanus]

Right, I have finally built the unit.

I would just like some clarification on the power to the LED's, I have set them up as 800ma to the RB's xpe and the CW's xpg. Is this correct, or should I adjust this to something else?

cheers

Happy New Year to All

[evilc66]

You will most likely be fine leaving it there, unless your tank is particularly deep.

[longimanus]

thanks for this, much appreciated

[longimanus]

Had the LED's running for the last few days, I have started them on 40% at the moment and am going to ramp them up over a few week.

My question is how do I know if my heatsink is doing its job properly. I had a tmc tile and it used to get really hot to touch, do I just keep checking it to make sure that it doesnt get any hotter?

Many thanks

[evilc66]

Many of us like to have the maximum heatsink temperature where you can hold your hand on it for a few seconds before it starts to get uncomfortable (about 140F/60C). Heatsink temperature isn't the best indicator of performance though, as you really should be looking at the LED die temperature, but it's more difficult to measure.

[longimanus]

ok, thanks for this, its not even hot yet then

cheers

[longimanus]

As my first LED build has now finished, I am thinking about building another to go over the tank.

For the old one I used meanwell dimmable driver, which worked very well.

For the new one I want to use a non dimmable driver as it will make it a bit cheaper, but would like to stick to the meanwell version. Can anyone point me in the direction of a meanwell driver that will power 12 CREE XPG/XPE Leds

Many thanks

[evilc66]

LPC-60-1050

[longimanus]

Thanks Again