4X QB120 boards... best driver for me??

Discussion in 'Lighting' started by roccus, Mar 16, 2018.

  1. I just ordered the 4X QB120 boards off of amazon I want to upgrade from my 2 300w purple LEDs I am using now. Right now I have a 3 X 3 tent but plan down the road to get a 4 X 4 tent. I am a bit confused on which driver would be best for me. Series vs. parallel wiring and some models they have are A and B version of. I would like to use a dimmable driver and get max watts out of the 4 boards. They say 70W is max per board so I can get a total of 280W for now. And who would have the best price for the driver I need? I am in US
  2. #2 mr.florista, Mar 16, 2018
    Last edited: Mar 16, 2018
    Mean Well
    HLG-240H-C2100 (in series) 50w per board
    HLG-320H-C2800 (max) (in series) 67w per board

    240 runs around 60 usd
    320 runs around 85 usd

    Great resource: LED Gardener - Learn to Grow With LEDs
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  3. Go to arrow.com. They'll have what you are looking for with decent prices. Courtesy of @Tbone Shuffle, he's the Quantum Man.

    J Evergreen
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  4. This one comes in two types C2100a & b. A has a dimmer, b does not.
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  5. A the dimmer is built in, B has external wires for a potentiometer.
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  6. Thanks guys this explains everything perfectly... I thought the 320 was the one I need but wanted to be sure
    So series is better than parallel for these lights?
  7. Series is the safer route, parallel is prone to thermal runaway.
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  8. 320h 2100a is the one you want to really max out 4 x qb132's. The qb120's are 60 watts each. The HLG 240h-c2100a is about the perfect driver.
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  9. The 320h 2100a would also work since it will put out 2100a but it's about 100watts higher capacity then you really need for 4 qb120's.
  10. Ahhh, 60w, well that changes it a bit.
  11. Any constant current driver that has the current amount at the end of the model number would be better hooked up in series. Some of the other drivers like the LRS series or ones with the voltage on the end are better in parallel.

    I have yet to see a single qb board burn out as a result of thermal runaway. Series is common practice with leds because of that but the danger of it with qb's is very low especially if you don't mix different loads on the driver. If they're all the same boards you'll be fine with parallel. Those diodes have taken 3-4 times their rated power in torture tests without burning up. I can't see a slight momentary increase in current they may experience when you have a burnout in parallel taking out one of these boards. They're pretty heavy duty and won't even turn on if they get too high of voltage.
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  12. I emailed HLG and asked if the max output of the 120 was 60 or 70W they said 70 was no problem with them.. the 2 purple LEDs I am running now put out 142W each so I have a total of 184W now, from everything I have read I figure running the 4 QB boards at 180W should blow the purple lights out of the water even though the power is about the same... I just hope the upgrade will be noticeable and pay off.. I wanted to go with the 288 boards but the price when you add in the sink is bit more than I can afford at this time
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  13. All of HLG's rated max powers for their boards are conservative so that they can run at that all day with no problems even in a hot grow room. You can actually count the diodes and check with samsung on the max wattage of each diode. If you do that you'll find that HLG is at least a good 200mA below max output on their ratings.

    There has to be a little safety there. That's why even though the qb132 is recommended to have a 2000mA max I recommend 2100mA drivers all day.

    It actually takes 2.5mA for a qb120 to be max power since it runs a lower voltage. That's one reason I bought single board drivers instead of powering four in series from a 2100mA driver. All my drivers are rated at 2500mA output on my 120's.
  14. So what are you putting out for watts per 120 board?
  15. 2.5 amps x 24 volts = 60 watts.
  16. 2.1 amps x 36 volts = 75.6 watts.
  17. I've heard that the qb120 can take up to 2800mA-3000mA actual max power. That would about equal 70 watts like you were talking about. They're not going to run as cool like that though.
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  18. The best drivers I've found for individual 120 boards for the price is the LRS-75-24. They're really cheap and won't have to run at max power to run the boards so they run very cool. The MDR-60-24's are also quite nice and cool running for a single board.
  19. Wow 36V must be really pushing these....
  20. That was to represent the qb132. The qb120 won't turn on if you give it over 24 volts. I've run into that on a few builds where the driver voltage output had to be turned down with a meter carefully to 24 before the lights would come on. I don't know how they build that in but the qb132's are the same. If your driver is putting out like 37.5 volts they won't come on. Some of them push past rated voltage a little when the voltage pot is turned all the way up. You have to carefully adjust them down to range with an accurate meter then the lights come right on.

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