DIY Quantum Board Tutorial - 10 Strips instead of 24 - Will it create thermal runaway?

[nuvan]

Hello fellow growers.

I’ve started my growing builds using the DIY Quantum Board tutorial: https://ledgardener.com/samsung-lm561c- ... g-touches/, reducing from 24 strips to 10 since I have a space restriction.
I thought that I could start small and add a few more strips later ( parallel ), but instead of getting the Mean Well HLG-320H-24A, I got the Mean Well HLG-320H-24 ( without the dimming feature ) which means CC and CV at the same time.

I’ve wired all strips in parallel, but I’m in a situation where I’m going to get thermal runaway eventually from my beginner accounting. Is this right?

Is there a way to drop half a volt from the driver before going through the light circuit?

And last, since I have 13.34 Amps to spend, it seems that I could add a few COBs within the voltage range (24V) besides adding a few more strips. Any drawbacks doing this?

In summary I have:

10 Samsung SI-B8T05128HUS Strips
Current - Test 240mA
Temperature - Test 50°C
Voltage - Forward (Vf) (Typ) 22.5V
Lumens/Watt @ Current - Test 187 lm/W

1 Mean Well Driver HLG-320H-24 (CC/CV without dimmer)
Voltage - Output 24V
Current - Output (Max) 13.34A
Power (Watts) 320W

I'll update this post later with a pic of my structure.

Thanks in advance and hope that everyone goes safe into 2021!

[TEKNIK]

Do you have an adjuster on your driver so you can dim the current or voltage down?

[nuvan]

"but instead of getting the Mean Well HLG-320H-24A, I got the Mean Well HLG-320H-24 ( without the dimming feature ) " unfortunately no and it is a bit hard for me to swap it since I've ordered from Digi-key and I'm in Portugal :\

[PeteR_1]

... I think I'm in a similar situation but with a CC&CV driver and all my strips are in parallel. Can you take a quick look?
viewtopic.php?f=32&t=6102&sid=3a7bae3db ... 811d3d5b9b

Your Selected Driver is very oversized and also has no adjustments, the 10 strips will be maxed out and running very hot.
I do not have any info on 1 - 2 Vf LEDs (COBs or Stars) or Resistors that can be used to increase the Vf (24 Vdc) of the individual Parallel strips to limit current flow...

I usually recommend the -AB suffix Meanwell HLG or XLG Series LED Drivers for their versatility. The -AB suffix Meanwell Drivers can be "Current Limited" down to 50% (-A) and then Dimmed between "10 - 100%" (-B)
The -B suffix Drivers being a close second because they can be Dimmed (Adjusted) down to 10% of maximum (10K Ohm) output with a connected 100K Ohm Pot or 10K - 100K Ohm Resistors.

Some Calculations;
Samsung Engine Calculator Tool... https://www.samsung.com/led/support/too ... alculator/
10 SI-B8T05128HUS / LT-H282D, 275mm Strips @ 93% Driver Efficiency

Calculated System Performance;
@ Typ. 0.240 A = 58 Watts, 22.5 Vdc, 10101 Lm, 173.9 lm/W @ 50°C Tc
@ Max. 0.600 A = 154.6 Watts, 24 Vdc, 23782 Lm, 144.5 Lm/W @ 90°C Tc

Driver rated @ 320 Watts @ 24 Vdc...
Note; 58 Watts is a HLG-320H-24B Dimmed to ~ 20% , 20K Ohm Resistor or adjusted Pot and 155 Watts is ~ 50%, 50K Ohm at Dimmer wires.

[nuvan]

@PeteR_1 many thanks for the info and help!
My accounting was more or less correct then ( unfortunately ).

"Your Selected Driver is very oversized and also has no adjustments, the 10 strips will be maxed out and running very hot." Yes they are I'm pulling 140-141W from the socket, and they are burning hot.
I've made a mistake when ordering this one but no worries.

Do you have any idea of a LED set that could squeeze this driver properly?

I'm thinking to get a few COBs sub 24V and some 24V fans

or,

increase the set of strips to 24-30 (it's going to get tight in my build),

to try to max out the 13.3 amps that the driver can pump ( all in parallel ). I don't see any other options since I don't know how to limit the current output :\


Again, thanks for your help!

[Sinfor]

You can use Schottky diodes in series. It will drop around 0.5V

[nuvan]

Thanks for the tip @Sinfor!
I don't know the component and I will check it later in the day.