MW XLG-240-H-AB with only one QB?

Hi,

Can I use a Mean Well XLG-240-H-AB with only one 120W Quantum Board panel?

Thank you all. I love this forum.

Should be ok. Output voltage Range is 27-54V I think. Most QBs are 48V

Youd need to keep it dimmed down to about 50%.

Thank you for reply.

My cards and my driver have finally arrived.

I adjusted the driver voltage before connecting to the board at 46.6V. I left the wires for the dimmer disconnected. Then I connected the wires and turned on the QB.

However, the QB and the driver get very hot (I am below the Equator line, midsummer).

If I connect one more card and keep both at 50%, would the system heat up less? I am calculating a resistance value to weld on the dimmer wires to obtain 50% of the power.

You can add a panel in parallel, and it'll divide the current in half, which will more or less halve the temperature.

zoiz said:

You can add a panel in parallel, and it'll divide the current in half, which will more or less halve the temperature per board.

Click to expand...

Yes this is correct.

FrankHerbert said:

Thank you for reply.

My cards and my driver have finally arrived.

I adjusted the driver voltage before connecting to the board at 46.6V. I left the wires for the dimmer disconnected. Then I connected the wires and turned on the QB.

However, the QB and the driver get very hot (I am below the Equator line, midsummer).

If I connect one more card and keep both at 50%, would the system heat up less? I am calculating a resistance value to weld on the dimmer wires to obtain 50% of the power.

Click to expand...

Why not use the potentiometer to dim it. You can dim it a lot lower that way. Then plug it into a Kill-a-watt to figure out the wattage draw. My XLG can go down to about 25 watts. But I just keep it at 180watts, so 90 watts per board, but I have 2 boards obviously.

PadawanWarrior said:

Why not use the potentiometer to dim it. You can dim it a lot lower that way. Then plug it into a Kill-a-watt to figure out the wattage draw. My XLG can go down to about 25 watts. But I just keep it at 180watts, so 90 watts per board, but I have 2 boards obviously.

Click to expand...

i dont think he has a pot. Hes just got open wires. so im guessing his only choice is 100% ....

These leds are badass. Your 125w board will do 200 watts with enough cooling to the board. probably 250 if liquid cooled.
Yours are naked so running 120 watts to each will still get hot. If you run 3 boards on that driver then they will not get very hot at all and will last forever. 4 boards will be dimmer but spread out better.... ect....

Your driver should have a built-in potentiometer where you can adjust the current with a small screwdriver.

Look for a black rubber lid on the backside of the driver. Remove it and you'll find the adjustable screw at the bottom.
Be careful when adjusting as the screw is made of plastic. A Kill-A-Watt is invaluable and should help with some of the headache Good luck!

Without the dimmer the driver seems to always try to deliver maximum power. I changed the configuration. I soldered a 50K resistor to the dimmer (equivalent to half the power in the specification table) and that completely changed the driver's operation. It works much cooler on quantum boards and the driver. Absolutely different

so I adjusted the potentiometer on the back of the driver (I could go to the maximum reading 42V on the board connectors)

it may be mandatory to weld some resistance on the dimmer. The power released on the board was unbelievable (without a dimmer). The system worked wrong for 14 hours, hot as the midday sun, 32ºC (90ºF) inside the tent. Very different from the videos I saw on youtube hahaha

Thank you very much for your help

Rocket Soul said:

Youd need to keep it dimmed down to about 50%.

Click to expand...

Mandatory. Without soldering the dimm contacts the driver will toast the board. I figured it would be enough to adjust the voltage at the back

PadawanWarrior said:

Why not use the potentiometer to dim it. You can dim it a lot lower that way. Then plug it into a Kill-a-watt to figure out the wattage draw. My XLG can go down to about 25 watts. But I just keep it at 180watts, so 90 watts per board, but I have 2 boards obviously.

Click to expand...

I don't have a 100K potentiometer but I will provide it. I'm also going after a Kill-a-watt. Excellent set

getogrow said:

These leds are badass. Your 125w board will do 200 watts with enough cooling to the board. probably 250 if liquid cooled.
Yours are naked so running 120 watts to each will still get hot. If you run 3 boards on that driver then they will not get very hot at all and will last forever. 4 boards will be dimmer but spread out better.... ect....

Click to expand...

After almost frying my board, I respect the leds a lot more.

FrankHerbert said:

After almost frying my board, I respect the leds a lot more.

Click to expand...

240 watts to one board!? yea thats going to get HOT. If you have an adjustable current then adjust it , thats your "dimmer". You dont need to homemake a resister.

I installed a 100k pot today (92k maximum, great).

The next step is to buy Kill-a-Watt, but that can wait.

Thank you for your help