4x4 Build Questions

Hey Everyone,

I have been creeping these forums as well as ledgardener and reddit and have decided to take the plunge into doing my own EB Gen2 Strip build. I just purchased a 4x4 tent and would like to build something to light it up, so I've come to you fine folks for a bit of help .

I understand basic electricity and the rules that follow it, or at least I would like to hope so. While reading some of the build options for 4x4 spaces I came across the 2' EB strip build (on ledgardener), I noticed that it had stated the following:

"System Voltage: 19.6V

System Current: 21,300mA

System Power: 417.5W"

How exactly does a HLG-480H-24A run 24x BXEB-L0560Z with a total system current of 21.3A when the driver itself is only rated for 20A maximum?

If I was to run 24xBXEB-L0560Z with 20A from driver, wouldn't each strip would receive roughly 834mA or is my math off? 20 of these would be 1A per strip if I'm not mistaken..

So if System Voltage is 19.6(ish) and we have 20,000mA, wouldn't the build only be producing 392W of power? If we are aiming for 480W for 16 sq/ft,. wouldn't this build be inadequate?

Any help or input appreciated.

acidzz said:

the driver itself is only rated for 20A maximum?

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Your doing the math correctly.... Meanwell drivers run "rich" compared to the data sheet values. Every MW I own proved underrated on paper, according to the Kill-a-Watt ….....My 240s get 270(ish) ….my 185s get 215.... ect

But digging further, that is a 24 volt driver, I dunno why they have that for a strip under 20v....Even the A version wont dial down to less than 20....maybe don't need to??? But I don't think that's getting the drivers full potential then.....The GEN1 EB strips had a higher V, would've needed that 24v for those, but not the Gen2s.....kinda weird...
2x HLG-240h-20A seems more suitable, 12x BXEB GEN2 560mm on each, would get to about 540w(ish) total...Plenty for 16sqft, from my experiences....

With those particular emitters,(most of my builds are BXEB) it really depends on how tightly they are arranged on a frame, and how far above the canopy they hang....I try to target 45K LUX at 8(ish) inches above the canopy...
A cheapish LUX meter, (Dr.Meter brand for example) $20 or so, is an invaluable tool for dialing in white LED arrangements.....

Thanks a ton @Chip Green appreciate the feedback.

One more question about parallel wiring with c.v drivers. If I only had one strip on the circuit, would all 12A of the HLG-240H-20A flow through it? or would it take the maximum of what the strip is rated for?

It is my understanding that HLG CV drivers are CV+CC, meaning that they have a CC mode, preventing the entire output from overloading current based on the strips I/V curve....or some shit like that LOL....that's one part I really still don't fully grasp enough to be able to explain confidently... lets try this, I need help here Heheee
@Randomblame
How does the CC mode on HLG CV+CC drivers kick on????

Chip Green said:

It is my understanding that HLG CV drivers are CV+CC, meaning that they have a CC mode, preventing the entire output from overloading current based on the strips I/V curve....or some shit like that LOL....that's one part I really still don't fully grasp enough to be able to explain confidently... lets try this, I need help here Heheee
@Randomblame
How does the CC mode on HLG CV+CC drivers kick on????

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Yeah, its not that easy to understand and it takes also a while for me to fully understand it.

A good rule of thumb is, the CC mode is used when the circuit voltage falls into the constant current area.
A type Meanwell's like the HLG-600H-48A with 48v have a constant current region(24-48v) and a voltage adjustment range(I believe it was 40,4-50,8v). As soon as you set the voltage higher than nominal, lets say to 49v, the driver is forced to work in CV mode but only if the connected LED modules need that much voltage. Only within the CC area the CC mode is used!

The voltage poti is to set a certain voltage limit because the voltage limits the current flow(an vice versa) and a voltage limit can protect the LED's from getting too much current. An HLG-600 with 48v has 12,5A from datasheet(probably 8% more so up to 13,5A)
A 4ft F-strip for instance needs 46v and takes 2,24a(at 65°C) if you look at the datasheet. With only 44v he would use less than 1000mA and with 48v he would probably run with up to 3amps.
So with a CV driver you can control current flow by limiting the maximal voltage and such limits are used to avoid damages to the LED modules. Max. current for F-strips is 200mA per diode or 3,6A (with 9 parallel rows of 16 diodes). To run the strip with 3,6A it needs 49v or more. When you set the limit to 49v its impossible to go above that limit no matter how much current the driver has. Even when one strip fails and there are only two strips left, they would still run with the set voltage limit and current flow would stay the same as with 3 strips.
But its even more complicated...
Lets say you have three 4ft double row strips on an HLG-480H-48A(10, probably up to 11amps) and you set the voltage limit to max. 50,8v. The strips would run with +180w each and the driver works in CV mode(550w at the wall).
But let's say you dimm the light down to 50% and the current flow goes down to 5-5,5amps. Each strip would get only 1,65-1,83amps and the circuit voltage would go down to 45,5v. So what will happen?
In the moment the voltage goes down and fit inside the CC region the driver would switch into CC mode. And if you ramp up again he switch back into CV mode.

For all this reason I always recommend to choose the driver and LED's so that the CC mode is used from the beginning.
You have 46v strips? Take an 48v driver. You have 50v COB's? Take the 54v version! If you do it this way there is no need to pull the rubber grommet of the voltage regulator. Just make sure there are enough modules in parallel to use all the driver current to max out the driver.

pulpoinspace said:

i think its rated for 20a max at 24v i.e. 480w
with the a-type MW u can adjust voltage and amperage
so if u lower voltage to 19.6v you can go higher on amperage

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An HLG-480H-24A has 20a from datasheet and can go as high as 108% with a bit luck, so absolute maximum is up to 21,6A.(or slighly more, see test report on MW website).
To set the voltage lower has no effect on max. current of the driver. Maximum stays between 20 and 21,6A! There is no way to exceed its maximum current.
But if you set the voltage manually higher to it's maximum the maximum current output will be reduced because of the safety mechanisms inside circuit design to avoid damages from overpowering and they have a few protection circuits to shut down the driver. In this case it starts blinking because the driver would retry to fire up the circuit.

@Chip Green @Randomblame

12x bxeb L0506z on hlg-240h-20a

12a x 19.5 = 234w x 2 = 468w?

Report for hlg-240h-20a says that "current adjust range is 1.58a ~12.2a

If I adjust the voltage to be 20v on the driver would the calculation be leaning more towards 12.2a x 20v = 244w x 2 = 488w max potential with 2 drivers and 24 strips (12 per driver)

I guess your comment about total 510w with two drivers threw me off a bit.

Just trying to figure out everything before making the purchsse.

acidzz said:

If I adjust the voltage to be 20v on the driver would the calculation be leaning more towards 12.2a x 20v = 244w x 2 = 488w max potential with 2 drivers and 24 strips (12 per driver)

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You'll be in that ballpark yes, these data sheet numbers tend to be slightly low compared to real action numbers, on a Kill-A-Watt meter.
I have mostly CC drivers to be fair....Building in series circuits like I did, is unnecessary, really a little dicey when the drivers get that size, awful lotta Voltage hanging around .... Built those before learning the parallel method, which is the preferred method going forward.
The only CV version I used is running a big ass veg light, I don't have it turned up all the way so I'm not certain on those honestly....

acidzz said:

@Chip Green @Randomblame

12x bxeb L0506z on hlg-240h-20a

12a x 19.5 = 234w x 2 = 468w?

Report for hlg-240h-20a says that "current adjust range is 1.58a ~12.2a

If I adjust the voltage to be 20v on the driver would the calculation be leaning more towards 12.2a x 20v = 244w x 2 = 488w max potential with 2 drivers and 24 strips (12 per driver)

I guess your comment about total 510w with two drivers threw me off a bit.

Just trying to figure out everything before making the purchsse.

Click to expand...

The HLG CV/CC driver are preset to their nominal output. 24A to 24v, 48A to 48v and so on. So an HLG-240H-20A is preset to 20v out of the box. No need to pull the rubber grommet.. 12 EBgen2 strips at ~1050mA should work well with the standard settings. You would probably don't see a difference if you turn up the voltage unless you use less strips to increase current flow and forward voltage of the circuit. With only 8 strips and 1,4A per strip they would need 20,5v but ~1020-1050mA should work like it is!

My question is this. Say I am running strips on a cv/cc driver with 10amp max. If I have 5 strips at 1800mA maximum and 6 strips at 500mA max, will it push a percentage of max to each strip or try to power them all at the same amperage(which would be too much for the smaller ones or too little for the bigger ones)?

manfromtn said:

My question is this. Say I am running strips on a cv/cc driver with 10amp max. If I have 5 strips at 1800mA maximum and 6 strips at 500mA max, will it push a percentage of max to each strip or try to power them all at the same amperage(which would be too much for the smaller ones or too little for the bigger ones)?

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It would depend on voltage. In any case its completly unrecommendable to power several different types of strips with different voltage and amp requirements by the same CV driver. You will blow some chips, and after blowing some the current in the rest of strips may increase and blow the rest.

All the strips are 24V, but, as far as the different amperage, that is why I put it in the range(12A on a 10A max cv/cc driver) where the cc side would kick in.

All parallel strings must be the same voltage and have the same voltage to current graph/relationship, which in practice mean all string must have the same chips/strips/cobs in the same bin on all strings. Just please dont put different stuff on different strings, you will have unexpected consequences...

manfromtn said:

All the strips are 24V, but, as far as the different amperage, that is why I put it in the range(12A on a 10A max cv/cc driver) where the cc side would kick in.

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If they really are the same voltage but have different max current: the current will be divided equally between the strips; not according to max current of the individual strips and your likely to burn some strips.

That is the answer I was looking for. I currently just run the setup on cc drivers. If running a 1750, I just parallel 4 of the 500mA and then run that in a series with the 1800mA strips. Or, with a 1400, I parallel 3 of the 500mA. It works great. I was just wondering if that was possible. They say it's only a dumb question if you know the answer. Thank you for the info.

manfromtn said:

That is the answer I was looking for. I currently just run the setup on cc drivers. If running a 1750, I just parallel 4 of the 500mA and then run that in a series with the 1800mA strips. Or, with a 1400, I parallel 3 of the 500mA. It works great. I was just wondering if that was possible. They say it's only a dumb question if you know the answer. Thank you for the info.

Click to expand...

Yup, thats all good.

When running long strings of long strips you may have some voltage drop which means you should have a few extra volts available on your driver. But if its just a couple of strips no worries