LED strips for a 4x1.5ft area

[grumps]

Great info, TEKNIK and The_Mouse_Police.

If I understood correctly, to run 6 strips, I'd configure the current to 4200mA (700mA x 6) and wire them in parallel. Should a strip fail for whatever reason, every remaining strip would get 840mA, which is still fine. Since the EB Gen 3s have a max current of 1400mA, four or more boards would have to fail before serious issues occur. Given that voltage limiting can't be used to protect against this case, I imagine that fuses could be placed in series with every LED strip if extra safety was desired, but the odds of that happening seem low.

Out of curiosity, if an LED strip is overdriven beyond its max current, would it typically burn out and stop working or would it catch fire?

Can I assume that, when connected in parallel, every LED strip will get the same current? (that is, can I assume that the equivalent resistance of every LED strip is the same?)

One more thought: you've established that buying a 24 v driver provides extra flexibility. Would there be any additional flexibility provided by using a 48 v driver instead? I imagine there could be three parallel connections, each having two LED strips in series.

[TEKNIK]

I would keep things basic and use a 24V driver. Alot more products for horticulture will be 24V soon. You could add 1 amp fuses to each strip but I don't think it's necessary, better to run an extra couple of strips as they are so cheap anyway. The strips won't usually burn out if they are overdriven providing they have enough heatsink. Definitely reccomend you run some aluminum angle on each strip as it will not only increase lifetime it will also increase performance. An oscillating fan blowing across your lights helps alot too.

[The_Mouse_Police]

Great info, TEKNIK and The_Mouse_Police.

If I understood correctly, to run 6 strips, I'd configure the current to 4200mA (700mA x 6) and wire them in parallel. Should a strip fail for whatever reason, every remaining strip would get 840mA, which is still fine.

On a CC driver, yes. On a CV driver, they'd still run at 700mA.

Out of curiosity, if an LED strip is overdriven beyond its max current, would it typically burn out and stop working or would it catch fire?

If over driven too much, it is likely to burn up the phosphors, and maybe damage the LEDs, including blowing some out, over a fairly short time. Fire is unlikely, unless you create an environment good for one to ignite.

Can I assume that, when connected in parallel, every LED strip will get the same current? (that is, can I assume that the equivalent resistance of every LED strip is the same?)

Yes, within a very tight tolerance. Every LED in each serial string will get the same current, exactly. By having several in series, Vf differences tend to average out between the strings, and you can assume it's all distributed perfectly across each LED, and also the strips themselves. I mean if one strip is taking 710mA and another 690mA, who cares?

One more thought: you've established that buying a 24 v driver provides extra flexibility. Would there be any additional flexibility provided by using a 48 v driver instead? I imagine there could be three parallel connections, each having two LED strips in series.

You could away with a bit less cabling in total, but then you can't do groups of 1, 3, or 5.

[grumps]

Thanks again for all the awesome info. Currently planning on getting the following:

Driver
XLG 200-24-A ($37.10 from Jameco)

I couldn't find the AB model for sale anywhere. But being able to adjust the current limit should be sufficient and I don't have a need for dimming so this should be ok?

LED Strips
Six 590mm strips with 80 CRI, 3500K: BXEB-L0590U-35E1500-C-C3 ($9.54 each from digikey)

A few questions:

1) An alternative: the 4000K strips are sold for the same price, and according to the datasheet, have a typical efficiency of 200 lm/W in contrast to the 186 lm/W provided by the 3500K strips Does this rating mean it's worth getting the 4000K or is the 3500K spectrum more optimal plants? I wish the datasheet had a PPFD/W rating or similar.

2) Digikey only has the Slim Gen 3 EB strips. Is that ok or should I try to look for the regular gen 3 series elsewhere?

3) The rated current of the driver is 8.3A. When the time comes to expand the growing space by purchasing another 6 strips, the total current consumed by the 12 strips would be 8.4A, which is just a bit over the rated current (is it close enough to still work?). But on the other hand, each strip has 13.4 W typical power, so 12 strips would consume 13.4*12 = 160.8 W. I presume that these results are different because the power calculation doesn't take into account the efficiency of the driver and that I should stick to a max of 11 strips?

[TEKNIK]

If you are using it for full growth the 3000k should be best, as they are cri80 they have alot of blue
Only the slim strips are available right now from my research.
Stick to 12 strips for spread and efficiency.

[unkle_psycho]

Yeah I have a bunch of 3000k and 3500k EB's and for some reason feel the 3000k stresses plants much less under intense lighting. I'm hoping to fix that by adding red to the 3500k strips, its just taking for ever to arrive.
Would defiantly go for 3000k if I was not planning on adding red. I don't think the umol/j values follow the lm/w.

[TEKNIK]

LPW and m/joule doesn't work the same at all. CRI changes things alot also. Peak lumens are in the green to amber range, peak micromoles is in the red and blue range, it's sort of the opposite. Plants also enjoy a nicer spectrum and CRI 90 is generally better even if the performance on paper isn't as good. You can't always judge a plant growth light of its color temprature though either.

[grumps]

3000k it is!

Here is my updated BOM:

POWER

• XLG 200-24-A ($37.10 from Jameco)
• NEMA 5-15P plug ($9.49 from home depot)

LIGHT
x12 590mm Bridgelux EB strips with 80 CRI, 3000K: BXEB-L0590U-30E1500-C-C3 ($9.54 each from Digikey)

HEAT SINK
Either of the following:

• x3 u-channel aluminum ($10.80 each from home depot) OR
• x12 15mm wide heat sink (about $35 with shipping from Heat sink USA)

FRAME
Built from 3/4 in. x 96 in. x 0.050 in. Aluminum Angle ($11.61 each from Home depot)

MISC

• Thermal tape to attach LED strips to heatsink ($15.99 from Amazon)
• Wago connectors ($9.25 for 10 connectors from Amazon)
• I have multistrand 18 AWG wire laying around. Is that thick enough?

Not sure if I'm forgetting anything but I'm excited to see it all come together!

[The_Mouse_Police]

Looks good. I would get something like these (5-pack), though, and affix the terminal block near the driver.

With wagos, 18 aught to be fine for a few inches just to split up between more wagos, but bigger would be better.

[slayking0113]

Except for the DIY, you can order the suitable led light on the market directly, I love simple
I use the mars hydro sp250,2pcs for my 4*4tent, they work so well, trust me, own one for your area, you won't regret it.
Somebody says I'm a faker, but no, I love sp250, my first led, and it's the best light at the same price. If you have more budget, you can choose other better chips lights.

https://www.mars-hydro.com/led-grow-lig ... r-for-sale