Changed my driver to double the power but light doesn’t seem any brighter?

Prawn Connery

Prawn Connery

Well-Known Member
ANC said:
my first LED grow was with 50 odd COBs, I remember those hated undervoltage... had to leave drivers set to max, and use current for dimming.
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I should explain that we do use the voltage limit function on our bigger builds because we have two 5A LED panels wired in parallel connected to a 480W (max 9.9A) driver. So if the connector on one panel burns out, then normally 9.9A would go straight to the other panel. By voltage limiting the driver, we can restrict the current to the other panel in the event one of them burns out.

Ideally, you don't want this to happen in the first place! But it has been known to happen with the waterproof TE connectors we use when running at 5A or higher. Most of the issues were with DIYers who were putting more than 5A through the LED panels, usually by accident (the Mean Well XLG drivers are notorious for raising the current as the LEDs warm up, because they will maintain a constant wattage – so as soon as the LEDs get warm and the forward voltage drops, the forward current goes up to compensate, which then exceeds the maximum current you just set! And on the XLGs, there is no way to hard-limit the current).

The High Light 420 LEDs I designed can actually go higher than 5A, but the waterproof connector is the weak point at that current. Even though the TE Slimseal connectors are rated at 5A, they are very marginal, and if you bump them in the course of lowering or raising your light then you can also compromise the metal pins inside, which can lead to failure. It did our collective heads in for a while trying to figure out how we could stop this from happening, but we now use conductive grease inside the connector to bolster the connection and maintain conductivity even if the metal pins inside get accidentally bent. So far, so good. But unfortunately there were a few warranty returns as a result. That's business – always learning, always trying to improve.
 
Boatguy

Boatguy

Well-Known Member
Prawn Connery said:
The High Light 420 LEDs I designed can actually go higher than 5A, but the waterproof connector is the weak point at that current. Even though the TE Slimseal connectors are rated at 5A, they are very marginal
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You need to try dt series deutsch connectors. We use them at work for a watertight removable connection.
They are rated to 13a and the pins are sturdy. The crimping tool is alittle expensive.
 
Prawn Connery

Prawn Connery

Well-Known Member
ANC said:
I'm not sure I'd go anywhere near 5A without good heat dissipation strategy
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In the case of our High Light 420 panels, they can run at 5A all day on a supplied heatsink. The PCBs panels are 430mm x 205mm x 2mm – 78% bigger than a Quantum Board at 285.75mm x 173.5mm x 1.6mm – and our aluminium heatsinks are literally twice as heavy. It's all a matter or perspective.
 
K

KitnerPush

Member
Prawn Connery said:
That's your problem right there. The HLG driver recommendations are for LED panels run in series, not parallel.

Running in parallel means you are only using 56V or less and the current is divided between each board. When you run in series you double the voltage but get full current to each board.

Wire them in series and report back.

And in future, if you want to run in parallel, use a constant voltage driver like you had originally – HLG-320H-54V for example – or re-wire your boards in series. That HLG-320H-C2100B is not designed to power 56V LEDs as the constant current region is 76-152V, so when they are wired in series (56V + 56V = 112V) they will be right where you want them to be.

BTW, 112V x 2.1A = 235W (series) whereas 56V x 2.1A = 117W (parallel). Those QB648s won't be drawing 56V at such a low current, so I'd guess you are probably only drawing 80-100W from the wall. So yes, you are getting less power from that 320W driver than from your original 150W driver.
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Hi, sorry for the resurrection, but I'm currently needing answers relating to this thread.

I'm looking to run 2 x qb648's in parallel and trying to find the best driver.

Seems HLG are using: 1696312283396.png The EUM-320S500MT

1696312360530.png
Does this mean that they are using series at 112Vdc x 2.1A? This would mean that the next driver, the EUM-320S760Dx, would be the correct driver for running in parallel? Is there any efficiency difference between using either of these methods?

The HLG 350 Diablo runs at 340watts. 5.6A @ 56V is 313.6W/93% is 337.2W.

The HLG 350 Diablo heat sink is only 0.09 inches/2.286 mm. That is thin AF!

Another thing I don't understand is that HLG claims to run the white diodes at 54mA and reds at 6x the current of whites, so 324mA. How does that translate to running 1296 white diodes and 36 red diodes at 56V and 5600mA?

Do you recommend any special driver to run these 2 boards in parallel? The Mean Well XLG-320-H seems like a good match, and it is priced well too? Please let me know.
 
Prawn Connery

Prawn Connery

Well-Known Member
KitnerPush said:
Hi, sorry for the resurrection, but I'm currently needing answers relating to this thread.

I'm looking to run 2 x qb648's in parallel and trying to find the best driver.

Seems HLG are using: View attachment 5332141 The EUM-320S500MT

View attachment 5332142
Does this mean that they are using series at 112Vdc x 2.1A? This would mean that the next driver, the EUM-320S760Dx, would be the correct driver for running in parallel? Is there any efficiency difference between using either of these methods?

The HLG 350 Diablo runs at 340watts. 5.6A @ 56V is 313.6W/93% is 337.2W.

The HLG 350 Diablo heat sink is only 0.09 inches/2.286 mm. That is thin AF!

Another thing I don't understand is that HLG claims to run the white diodes at 54mA and reds at 6x the current of whites, so 324mA. How does that translate to running 1296 white diodes and 36 red diodes at 56V and 5600mA?

Do you recommend any special driver to run these 2 boards in parallel? The Mean Well XLG-320-H seems like a good match, and it is priced well too? Please let me know.
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@CobKits is a sponsor here and has some good info on those QB648 boards here: https://cobkits.com/product/qb-648-diablo/

If you want to run them in parallel, then you need a 54-60V constant voltage (CV) driver. If you plan to run at lower currents, then a CV 54V driver will work – esepcially if you run a Mean Well A or AB type driver that will output well above 54V.

The XLG-320-H-AB will work, but I'm not a huge fan of the XLG series as they are a constant power driver, which means they adjust both current and voltage to match desired wattage instead of being able to current limit or voltage limit the driver – which is an important consideration when wiring in parallel, because you can voltage limit the driver to prevent thermal ruanway in the event one of the boards becomes disconnected.

We've also seen a number of failures of XLG drivers due to the way the internal potentiometers are set up.

I don't know which country you are in, so hard to advise altenatives because the ELG series only goes to 75% on 110V mains (North America, Japan etc) but you can get full power out of them on 230V mains (Europe, Australia etc).

A HLG-320H-54A or AB will definitely work – they go up to 60V and we get up to 380W out of them with our lights (GLA).

There will be other brand drivers available that will do the same, depending on where you live.

Series vs parallel will depend on the following:

Series wiring is a little bit more efficient and can provide insurance against thermal runaway, but is less flexible when wiring boards together and results in higher voltages – which can be illegal in your country and is more dangerous. In Australia, continuous DC voltage under 60V and pulsed voltage under 120V is considered "safe" (SELV = "separated extra-low voltage") and is not regulated. Anything over that needs to be isolated with an accompanying saftery certificate.

The reason series wiring is a little bit more efficient is due to the reduced current (high voltage = lower current; low voltage = higher current for same Wattage), which usually results in less resistance.
 
K

KitnerPush

Member
Prawn Connery said:
@CobKits is a sponsor here and has some good info on those QB648 boards here: https://cobkits.com/product/qb-648-diablo/

If you want to run them in parallel, then you need a 54-60V constant voltage (CV) driver. If you plan to run at lower currents, then a CV 54V driver will work – esepcially if you run a Mean Well A or AB type driver that will output well above 54V.

The XLG-320-H-AB will work, but I'm not a huge fan of the XLG series as they are a constant power driver, which means they adjust both current and voltage to match desired wattage instead of being able to current limit or voltage limit the driver – which is an important consideration when wiring in parallel, because you can voltage limit the driver to prevent thermal ruanway in the event one of the boards becomes disconnected.

We've also seen a number of failures of XLG drivers due to the way the internal potentiometers are set up.

I don't know which country you are in, so hard to advise altenatives because the ELG series only goes to 75% on 110V mains (North America, Japan etc) but you can get full power out of them on 230V mains (Europe, Australia etc).

A HLG-320H-54A or AB will definitely work – they go up to 60V and we get up to 380W out of them with our lights (GLA).

There will be other brand drivers available that will do the same, depending on where you live.

Series vs parallel will depend on the following:

Series wiring is a little bit more efficient and can provide insurance against thermal runaway, but is less flexible when wiring boards together and results in higher voltages – which can be illegal in your country and is more dangerous. In Australia, continuous DC voltage under 60V and pulsed voltage under 120V is considered "safe" (SELV = "separated extra-low voltage") and is not regulated. Anything over that needs to be isolated with an accompanying saftery certificate.

The reason series wiring is a little bit more efficient is due to the reduced current (high voltage = lower current; low voltage = higher current for same Wattage), which usually results in less resistance.
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Thanks for a good answer! I also see that these qb648 boards are rated at 5000mA maximum. At 56v that is 280w, at 58v it is 290. Meaning two could be powered by a HLG-480-54-A/AB?

If so, what type of heat sinking do you think would be necessary?

I mean getting 380w out of a 320w driver is pretty good, but maybe running a 480w driver would let me hang the lights higher? Or do you think it would be overpowering the boards leading to lower lifetime of the diodes? Pls let me know so I can make an informed decision
 
Rocket Soul

Rocket Soul

Well-Known Member
KitnerPush said:
Thanks for a good answer! I also see that these qb648 boards are rated at 5000mA maximum. At 56v that is 280w, at 58v it is 290. Meaning two could be powered by a HLG-480-54-A/AB?

If so, what type of heat sinking do you think would be necessary?

I mean getting 380w out of a 320w driver is pretty good, but maybe running a 480w driver would let me hang the lights higher? Or do you think it would be overpowering the boards leading to lower lifetime of the diodes? Pls let me know so I can make an informed decision
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Youd need aircooled heatsinking, preferably with a fairly thick base plate. It would lower lifetime somewhat in theory. It would allow but also force you to hang the lights higher.

For high wattage qb operation: theres a nice primer on youtube, from ledgardener.
 
K

KitnerPush

Member
Rocket Soul said:
Youd need aircooled heatsinking, preferably with a fairly thick base plate. It would lower lifetime somewhat in theory. It would allow but also force you to hang the lights higher.

For high wattage qb operation: theres a nice primer on youtube, from ledgardener.
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Thanks! Very interesting video. But how does HLG get away with a 0.09 inch heatsink running two of them at 340w? What would you say would be the best performance benchmark? Still 340w or maybe somewhere between 340-400w? Without air cooling and using a slightly modified slate-type heat sink?
 
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KitnerPush

Member
If my math is correct, then at 65mA each board has 36 x 65mA which is 2340mA. HLG states that reds are 6x the current of white so at 65mA then reds are 390mA. So 2 x qb648 should be 2340(2) + 390(2) = 5460mA for test current of whites. I'm not sure how they can claim whites are run at only 54mA if they are pushing 340w per 2 qb648. They must be talking about running 6 at 720w... their 4 board version is running at 720w also, which means they are running each board at a little over 3200mA?
 
K

KitnerPush

Member
Also per samsung LED calculator, it seems that 1296 white diodes at 2.78V x 18(white) is only 50.4V and 3 reds per 18x6, would mean a total voltage of 56.55V if red is 2.05v:


Acording to the calculator you can push 1296 diodes to 181mA before it goes to 'warning zone' for thermals. This is 694.2 watts with only about 22lm/w loss in efficacy over test current 65mA. If reds are 6x the current of white, then that means 817w total before the calculator kicks into 'warning zone.' This calculator seems whacked??
 
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Prawn Connery

Prawn Connery

Well-Known Member
You are not going to get 280W out of each of those boards. I mean, you will, but they will run so hot that they will probably burn out after a short time. It could be days or weeks or possibly even a couple of months, but they will be heat stressed until the individual diodes start to drop out.

Go back to the CobKits link and see what drivers they recommend for each combination of boards. The hottest they are running them is 2x boards with heatsinks on a 320W driver. The standard QB footprint is 286mm x 174mm. The High Light 420 boards I designed are 430mm x 205mm – 1.8x the surface area. As in, almost twice as large. And the most we reliably run through each of our panels is around 240-250W. And that is with a heatsink that is bigger and heavier than the HLG offering. That is passive cooled – although most grow rooms have air blowing through them, so technically speaking, they are not "passively" cooled.

The bottom line is, you can run phenomenal amounts of current through an LED . . . as long as you have phenomenal heat dissipation. It's all about the heat disspiation. If you want to build yourself a water-cooled heatsink, then you will be able to push those LED panels much harder.
 
Rocket Soul

Rocket Soul

Well-Known Member
KitnerPush said:
Thanks! Very interesting video. But how does HLG get away with a 0.09 inch heatsink running two of them at 340w? What would you say would be the best performance benchmark? Still 340w or maybe somewhere between 340-400w? Without air cooling and using a slightly modified slate-type heat sink?
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I dont advice to drive any board that hard. You can. But should you?
You mentioned hanging lights higher: this will make you lose lights to the wall. If youre in a tent theres always height limitation.

I added the vid just for laughs, its interesting to see how hard you can drive these without catastrophic failure. Qb type, with these dimensions; i generally think that 80w is the sweetspot for hanging height and coverage. Goes for both regular, qb648 or china qbs; its based on its dimensions, coverage are and even spread. I would not run qb648 at 160+ watts.
 
K

KitnerPush

Member
Rocket Soul said:
I dont advice to drive any board that hard. You can. But should you?
You mentioned hanging lights higher: this will make you lose lights to the wall. If youre in a tent theres always height limitation.

I added the vid just for laughs, its interesting to see how hard you can drive these without catastrophic failure. Qb type, with these dimensions; i generally think that 80w is the sweetspot for hanging height and coverage. Goes for both regular, qb648 or china qbs; its based on its dimensions, coverage are and even spread. I would not run qb648 at 160+ watts.
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Alright, I can live with pushing them at 5.6A x 56v. Which is 313W. Then the XLG-320 would probably do the job.
 
K

KitnerPush

Member
Prawn Connery said:
You are not going to get 280W out of each of those boards. I mean, you will, but they will run so hot that they will probably burn out after a short time. It could be days or weeks or possibly even a couple of months, but they will be heat stressed until the individual diodes start to drop out.

Go back to the CobKits link and see what drivers they recommend for each combination of boards. The hottest they are running them is 2x boards with heatsinks on a 320W driver. The standard QB footprint is 286mm x 174mm. The High Light 420 boards I designed are 430mm x 205mm – 1.8x the surface area. As in, almost twice as large. And the most we reliably run through each of our panels is around 240-250W. And that is with a heatsink that is bigger and heavier than the HLG offering. That is passive cooled – although most grow rooms have air blowing through them, so technically speaking, they are not "passively" cooled.

The bottom line is, you can run phenomenal amounts of current through an LED . . . as long as you have phenomenal heat dissipation. It's all about the heat disspiation. If you want to build yourself a water-cooled heatsink, then you will be able to push those LED panels much harder.
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Ok, so what you are saying is that there is little or no point in trying to run them above 5600mA - 56V which would be 333w total? Or are you saying that boards at max 320w or 5.72 max with 94% driver for total of 340w. If HLG are running them at this range with a 2.22mm heat sink, then it can hardly be an issue running them at this load.

The only thing i don't understand is that the qb288's are max 3000mA per board, although most people are not running this board higher than150w or 2800mA safely. But this board also has more than half the diodes, granted it is 54v not 56v.

Watercooled is a bit too much for my likeing. I think there is a reason ChilLed moved away from this as well. Simple is probably better. I'm looking at the Sosen 320w driver, seems like a solid driver for a good price.
 
Prawn Connery

Prawn Connery

Well-Known Member
KitnerPush said:
Ok, so what you are saying is that there is little or no point in trying to run them above 5600mA - 56V which would be 333w total? Or are you saying that boards at max 320w or 5.72 max with 94% driver for total of 340w. If HLG are running them at this range with a 2.22mm heat sink, then it can hardly be an issue running them at this load.

The only thing i don't understand is that the qb288's are max 3000mA per board, although most people are not running this board higher than150w or 2800mA safely. But this board also has more than half the diodes, granted it is 54v not 56v.

Watercooled is a bit too much for my likeing. I think there is a reason ChilLed moved away from this as well. Simple is probably better. I'm looking at the Sosen 320w driver, seems like a solid driver for a good price.
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What I'm saying is you can run them as hard as you want if you don't value lifespan or efficiency.

In the case of Quantum Boards vs LED count, it really has nothing to do with the number of LEDs – they aren't the limiting factor in the QB648 – and everything to do with the size of the panels and how much heat the PCB/heatsink can dissipate.

I don't know how else to explain this to you. When LEDs get hot, they lose efficiency and eventually burn out. If you want to know who much current to run through them, follow the recommended guidelines or ask the maufacturer or just go ahead and do what you want and see what happens. You might get lucky. Or not.

It is the heat that the current generates that damages LEDs, not the current itself (strictly speaking), so everything relies on thermal management.
 
Rocket Soul

Rocket Soul

Well-Known Member
KitnerPush said:
Ok, so what you are saying is that there is little or no point in trying to run them above 5600mA - 56V which would be 333w total? Or are you saying that boards at max 320w or 5.72 max with 94% driver for total of 340w. If HLG are running them at this range with a 2.22mm heat sink, then it can hardly be an issue running them at this load.

The only thing i don't understand is that the qb288's are max 3000mA per board, although most people are not running this board higher than150w or 2800mA safely. But this board also has more than half the diodes, granted it is 54v not 56v.

Watercooled is a bit too much for my likeing. I think there is a reason ChilLed moved away from this as well. Simple is probably better. I'm looking at the Sosen 320w driver, seems like a solid driver for a good price.
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If you want long lasting leds try to make the diode temp less than 50C.

To me its completely pointless running a qb size board, 180x280mm-ish, at those high wattages:
In a open space: high hanging height which means a lot of the light will not fall on cannopy.
In a tent: high hanging height will eat up vertical space where the plant could grow and yield.

Edit : Maybe speak some to people who are already running the hlg350; i know @2cent had problems running those on full power, i think he got light bleaching and stuff.
 
curious2garden

curious2garden

Well-Known Mod
Staff member
Rocket Soul said:
If you want long lasting leds try to make the diode temp less than 50C.

To me its completely pointless running a qb size board, 180x280mm-ish, at those high wattages:
In a open space: high hanging height which means a lot of the light will not fall on cannopy.
In a tent: high hanging height will eat up vertical space where the plant could grow and yield.

Edit : Maybe speak some to people who are already running the hlg350; i know @2cent had problems running those on full power, i think he got light bleaching and stuff.
Click to expand...
@Laughing Grass runs 2 HLG 350R's, quite successfully
 
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