Limiting the voltage on meanwell drivers

MustGro

Well-Known Member
Does anyone go in and adjust the voltage on their Meanwell drivers? I first read about it on the Grow Lights Australia site and didn't think much about it.
I went into my room last month and there was a new smell there. I've had electrical equipment, HPS and CFL lights go bad and there is a unique smell from each one but this was a new one. One of my Wago connectors had dropped it's wire and all of the power from the Meanwell was going to one board. It didn't kill it but I doubt it did the board any good. I think I'll pop off the Vo ports and dial the voltage down but I was wondering if anyone else has done this.
Here's a link to the site and a quote from the article.


Step 5
You may now choose to voltage limit your LEDs by slowly turning the voltage dial down until just before it starts to reduce the power at the wall meter. Limiting the voltage in this way will ensure that if, for example, you have multiple boards wired up in parallel and one or more boards become accidentally disconnected, the remaining boards will not draw all the current and potentially burn out, because the driver will kick into constant voltage mode.
 

Grow Lights Australia

Well-Known Member
Hi mate, just out of curiosity were those boards ours?

The description of how you adjusted your veg light is spot on. This is how we recommend setting the voltage on all Mean Well type constant voltage drivers. The only real issue is that LED voltage requirements decrease with heat. This is what can lead to thermal runaway. The LED heats up, its voltage requirements drop, the LED draws more current at the supplied voltage so continues to heat up as the voltage requirements continue to drop and around it goes until the LEDs burn out.

If you voltage match LEDs like we do, then this reduces the potential for thermal runaway, but the only real way to protect against it in a parallel circuit is to limit voltage, just as you have done. It's not the actual current that kills LEDs, but rather the heat. We have seen LEDs that were super-cooled that could handle many times their maximum rated current.

If anyone needs any help with this or has any questions we'd be happy to answer.
 

MustGro

Well-Known Member
Hi mate, just out of curiosity were those boards ours?

The description of how you adjusted your veg light is spot on. This is how we recommend setting the voltage on all Mean Well type constant voltage drivers. The only real issue is that LED voltage requirements decrease with heat. This is what can lead to thermal runaway. The LED heats up, its voltage requirements drop, the LED draws more current at the supplied voltage so continues to heat up as the voltage requirements continue to drop and around it goes until the LEDs burn out.

If you voltage match LEDs like we do, then this reduces the potential for thermal runaway, but the only real way to protect against it in a parallel circuit is to limit voltage, just as you have done. It's not the actual current that kills LEDs, but rather the heat. We have seen LEDs that were super-cooled that could handle many times their maximum rated current.

If anyone needs any help with this or has any questions we'd be happy to answer.
No, not your boards although I REALLY like your 420 kits. Great info on your site too.
I run 4 of these kits https://www.growlights.ca/250-watt-fb288-lm301h-3000k-660nm-uv-ir-led-fusion-board-light.html
 
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