For those that have done strips DIY need advice on driver selection...

[tilopa]

This is my first LED build, and I don't want to f it up.

This is for a 4x4 flower space. Using 20 2-foot Bridgelux Gen 3 but using a 4ft bar. 2ft is all I can find available for the strips that I want.

I'm going with a mix of 10 4000k 90 CRI and 10 3000k 80 CRI. My reasoning is that this is a good balance between increased spectrum range while keeping it at a decent efficiency. If anyone feels strongly that this is a bad idea please let me know and why.

Wiring all 20 in parallel for simplicity. For the driver, at first I was going to go with HLG-480H because I thought I needed that many watts - still learning. Seeing others on the forums using HLG-320H for this amount of leds, so would like to do that.

Where I'm having trouble is with the specific driver. It seems like the HLG-320H-24b would be best for my strips, the voltage range for those strips is 17v-21v. But with that driver my current would only be about 667mA per strip and wattage of 252 which seems a little under powered. The flux per strip would be less than 100%. I don't want to max it out or anything, I'd like to hit a mid range sweet spot of good flux, with decent efficiency and relatively low heat - I'll be using aluminum angle at minimum for heatsink.

As I said this is my first build so I'm wondering if the drivers have some kind of control knob that allows you to increase current and or voltage, so I could tune it a little bit higher if I use the HLG-320H-24?

Also, I've been seeing people talking about efficiency in micromouls per joule, and weather a configuration will have too much or little PPF. How do I calculate these measurements given the driver build I'm considering using?

 

[Airwalker16]

A 1:1 4000k/3000k mix is a lot better than 3000k/5000k. So I'd say you're in a good spot there. Plus the 80cri 3000ks GA e that extra boost of red. But if it's going to be used for strictly flowering and you haven't bought the strips yet, I would definitely recommend, at least, using all 3000k. You really don't need the 4000k. All it does is add more Blue than you need and less red which you do need. But its up to you. Either way you'll do fine. But all 3000 I think you'd be happier with the end results.
Now as for the driver, 320watts is absolutely NOT enough for an entire 4x4 tent. You definitely need the 480 or even better so, 2- 320s for the extra wattage if you find yourself needing it.

 

[cobshopgrow]

have you checked the HLG 42V drivers?
maybe consider to put 2 in series each to get at ~40V, thats halving your amps and ease the load.

 

[Airwalker16]

have you checked the HLG 42V drivers?
maybe consider to put 2 in series each to get at ~40V, thats halving your amps and ease the load.

Really good idea.

 

[tilopa]

have you checked the HLG 42V drivers?
maybe consider to put 2 in series each to get at ~40V, thats halving your amps and ease the load.

I'm not quite following you, do you mean take two strips and wire them in series, then take those 2 and connect them with the remaining 8 in parallel? Or do you mean wire to sets of 5 in parallel then wire those 2 sets in series?
In any case, how does that ease the load? There are clearly some holes in my knowledge here, any help is appreciated.

 

[Airwalker16]

I'm not quite following you, do you mean take to strips and wire them in series, then take those 2 and connect them with the remaining 8 in parallel? Or do you mean wire to sets of 5 in parallel then wire those 2 sets in series?
In any case, how does that ease the load? There are clearly some holes in my knowledge here, any help is appreciated.

He's meaning wire 2 of your 19.5v strips together in series for a 40V sum, and treat it as a whole to be wired in parallel to the driver by connecting the open Pos+ terminal on the first strip and the open Neg- terminal of the second. Repeat this with 8 more strips to make 4 more.

 

[cobshopgrow]

i explained terible, my fault.
just ment what airwalker explained in much more detail above.

one other thought, may take one 4000k and one 3000k in this described series pair.
if there is as voltage dif. (which idk), you would be on the safe side.
lets say the 4000k pull 0.1V then the 3000k (which again, idk!) having them evenly distributed in this series/parallel mix should be the safest way to my opinion.
problem is, this way you cant play around with the color temps, that would need 2 drivers then, which puts you in the XLG 200 or XLG 240 section.
So maybe one XLG 200 or 240 for each color temp, then 2 strips of the smae color in series of course.
there are quite some option, may dig in to their datasheets, youre quite free to configure whatever makes sense for you.

"ease the load" just ment that it halves the needed ampere and you can get away with thinner cables and/or have less losses on these.

Otherwise nice combination of strips, let us hear your results..

 

[Rocket Soul]

For real low amps per strip you can probably even use a 36A driver, most of those go to 40iish V and eb gen3 goes ddown quite low, llike 18 and change on sub nominal current...

 

[tilopa]

Thanks all. There are so many options and configurations for drivers, it's a bit confusing on what to focus on. Relative to efficiency, in general, is it better to go with higher voltage and lower amps?

I feel like I might need to try and simplify things for my first build. The more I learn the more options there seem to be. I thought I was clear about what I would do, and I need to move forward on this, and I'm starting to feel like a deer in headlights, frozen with indecision.

Maybe I should not mix the 4000k and 3000k and just do 3000. But, to be clear, Airwalker, the 4000k are 90 CRI. Take a look at the sprectral graph here: https://www.bridgelux.com/sites/default/files/resource_media/DS132 Bridgelux EB Series Gen3 Data Sheet 20190617 Rev A.pdf
The 90 CRI has way more red in the 660nm and some far red, but at a cost of efficiency. I wanted to try and get a little bit more of the higher nm reds.

One other option I'm thinking about is just getting the standard 3000k 80 CRI and add some strips of red. Does anyone know of a good supply of red strips? Problem with that is I need to get a separate driver just for those right?

Really need to make a decision soon so any help is appreciated.

 

[Airwalker16]

Thanks all. There are so many options and configurations for drivers, it's a bit confusing on what to focus on. Relative to efficiency, in general, is it better to go with higher voltage and lower amps?

I feel like I might need to try and simplify things for my first build. The more I learn the more options there seem to be. I thought I was clear about what I would do, and I need to move forward on this, and I'm starting to feel like a deer in headlights, frozen with indecision.

Maybe I should not mix the 4000k and 3000k and just do 3000. But, to be clear, Airwalker, the 4000k are 90 CRI. Take a look at the sprectral graph here: https://www.bridgelux.com/sites/default/files/resource_media/DS132 Bridgelux EB Series Gen3 Data Sheet 20190617 Rev A.pdf
The 90 CRI has way more red in the 660nm and some far red, but at a cost of efficiency. I wanted to try and get a little bit more of the higher nm reds.

One other option I'm thinking about is just getting the standard 3000k 80 CRI and add some strips of red. Does anyone know of a good supply of red strips? Problem with that is I need to get a separate driver just for those right?

Really need to make a decision soon so any help is appreciated.

No need forced supp with all 3000km maybe with the mixed 4000k. If you really wanna add some extra red,pick up 4-5 2700k strips to evenly mix into your setup. That's sou ding like what you're after.
10-3000k.
6-4000k
4-2700k

 

[4ftRoots]

Just get a total of 24 strips. Buy 2 HLG-240-1050b drivers then dim to the power level you need. 24 strips fit perfect on the driver. Maybe more since you are using gen 3's

 

[Airwalker16]

Just get a total of 24 strips. Buy 2 HLG-240-1050b drivers then dim to the power level you need. 24 strips fit perfect on the driver. Maybe more since you are using gen 3's

Again, don't encourage high voltage driver if it doesn't need to be used. HLG-320H-##A is much safer.

 

[4ftRoots]

Again, don't encourage high voltage driver if it doesn't need to be used. HLG-320H-##A is much safer.

I've never understood the problems with high voltage drivers. With proper wiring they are a non issue. I have many strip modules running on the same driver. Foliar feed all the time. The strips were made to work with high voltages so no need to be afraid. I would be more afraid of thermal runaway than anything. Of course, both situations likely hood of happening is incredibly low.

 

[Airwalker16]

I've never understood the problems with high voltage drivers. With proper wiring they are a non issue. I have many strip modules running on the same driver. Foliar feed all the time. The strips were made to work with high voltages so no need to be afraid. I would be more afraid of thermal runaway than anything. Of course, both situations likely hood of happening is incredibly low.

With 24 strips, 6 could suddenly stop working and it'd be just fine for the remaining 18 to split that current amongst them. But 300+ DC volts to the heart? Ya you're dead as fuck..

 

[4ftRoots]

With 24 strips, 6 could suddenly stop working and it'd be just fine for the remaining 18 to split that current amongst them. But 300+ DC volts to the heart? Ya you're dead as fuck..

I'd like to state, they are both the same in terms of safety at the same current. Both will shock you because of the voltage levels. Being cognisant of the potential dangers is what will save people. Not babying them into a lower voltage driver. I've personally talked with Meanwell about the higher voltage driver. It has electrical isolation so shock will likely never happen.

There is a great Mythbusters about voltage and current. Voltage does not kill you, current does. That's why electric cow fences are not banned from the face of the earth. They are safe enough to be used by cowboys with limited electrical understanding. I'll find the video

 

[4ftRoots]

Here is the video. Electric cow fence through the heart. No issues. Definitely dangerous, but he didn't suffer because the current is minuscule, which is the important part.

 

[4ftRoots]

With 24 strips, 6 could suddenly stop working and it'd be just fine for the remaining 18 to split that current amongst them. But 300+ DC volts to the heart? Ya you're dead as fuck..

Just for fun as well, let's say you have 24 strips running at 1050mA without a heatsink. Totally ok.

12v per strip * 24 = 288v

288v * 1050mA = 302w driver.

6 strips stop working = 302w spread through 18 strips.

302w/(18*12v) = 1400mA. This could be hot enough to not only blow your leds, but kill your plants if you do not have proper ventilation or burn down your house if the wire insulation melts.

If you have all in series, as LEDs were made to be run. One goes out they all go out.



Just do it right guys

 

[tilopa]

Just get a total of 24 strips. Buy 2 HLG-240-1050b drivers then dim to the power level you need. 24 strips fit perfect on the driver. Maybe more since you are using gen 3's

Just for fun as well, let's say you have 24 strips running at 1050mA without a heatsink. Totally ok.

12v per strip * 24 = 288v

288v * 1050mA = 302w driver.

I'm confused, do I need two HLG-240-1050b, like you said in first post or just one?

Actually the strips have a minimum forward voltage of 17.8, so you can't run them at 12v per strip.

 

[tilopa]

For real low amps per strip you can probably even use a 36A driver, most of those go to 40iish V and eb gen3 goes ddown quite low, llike 18 and change on sub nominal current...

Damn, man I wish you guys would explain these responses just a wee bit more. Why would I want to run an 18v strip on a 40ish v driver?

 

[loco41]

I got 20 of the 4k 90cri coming, 2 ft strips, and was thinking of running them like @Randomblame and @cobshopgrow were saying. Probably wire two strips in series together then the 5 sets in parallel on a hlg-120-36. Haven't ordered any drivers yet, but just what I'm thinking so far. I haven't built a strip light yet, but just my two cents for what I'm thinking..