Bridgelux EB-series on a 2' x 4' SCROG

Chip Green

Well-Known Member
Its adding up to me, 4 of the 1120mm EBs on each MW185.... I basically have the same thing going, only I have 8 EB 560mm strips on each MW185/1050....
 

canadian1969

Well-Known Member
Its adding up to me, 4 of the 1120mm EBs on each MW185.... I basically have the same thing going, only I have 8 EB 560mm strips on each MW185/1050....
I dunno, it was Daniel and Vegas that mentioned it as the OP said something about being only 175 watts at the wall or something. I dont think its dimmed as that driver doesn't dim, just the ones with B at the end right?

How did you wire yours?
 

Danielson999

Well-Known Member
Not really you can get them to touch the plants..
Its all because its spread over a large surface area,unlike a single source from a HPS...
And they run cooler as well..
Because you dont need the same watts,you can use say 450 as a replacement for a 600 because of efficiencys..
400w of strips give off the exact same amount of heat that 400w of cobs do. It's a misconception that they run cooler.

But having said that, I don't believe the OP has 400w running in his 2'x4' tent. It looks far too dim in there to me.
 

graying.geek

Well-Known Member
The drivers can max at 200w each with full Vf forward voltage. If you add up voltage you will find you could probably run the entire string on one driver instead of two and be efficient too
Yeah, this all makes sense to me from the perspective of the output side of the driver, but what confuses me is trying to balance driver input with driver output. If I understand correctly (this is probably the problem), if each driver puts out 190v, in a 4-strip serial configuration each strip will receive 47.5v at 1.05a = 49.9w. So 4 strips on each driver should be using ~49.9w (47.5v * 1.05a). For 8 strips I would expect the 2 drivers to pull 8 * 49.9w = 400w on the input. But when I plug both drivers into a kilowatt meter, I get 116.5v, 1.08a, 122w (this should be 116.5v * 1.08a = 125.8w but I attribute the difference to the $20 kilowatt meter).

It seems like watts in should = watts out, but there's clearly an error in the way I'm looking at this or I'm wired wrong (I'll post pics of my wiring later today). Whatever I'm missing, any lucidity you can bring to this would be appreciated.
 

MrTwist1

Well-Known Member
Yeah, this all makes sense to me from the perspective of the output side of the driver, but what confuses me is trying to balance driver input with driver output. If I understand correctly (this is probably the problem), if each driver puts out 190v, in a 4-strip serial configuration each strip will receive 47.5v at 1.05a = 49.9w. So 4 strips on each driver should be using ~49.9w (47.5v * 1.05a). For 8 strips I would expect the 2 drivers to pull 8 * 49.9w = 400w on the input. But when I plug both drivers into a kilowatt meter, I get 116.5v, 1.08a, 122w (this should be 116.5v * 1.08a = 125.8w but I attribute the difference to the $20 kilowatt meter).

It seems like watts in should = watts out, but there's clearly an error in the way I'm looking at this or I'm wired wrong (I'll post pics of my wiring later today). Whatever I'm missing, any lucidity you can bring to this would be appreciated.
LEDs only pull as much as the forward voltage they are rated for. Your strips likely each draw around 24v each so what your Kill a watt is telling you is certainly in the right range. You could probably run all of those strips off one of those drivers, although technically you would be slightly out of advertised spec (but it would likely work fine). If you want more power you will either need to run the strips harder (not really recommended) or buy more of them. I would go for another 8 :)
 

BuddyColas

Well-Known Member
This is what I'm concerned with. Perhaps the serial wiring pattern I used is incorrect. Here's what I have. Input appreciated:View attachment 3965819
Your 4 strips are wired in parallel...what you want is to wire them in series. And when you do, better move your lights up and/or dim because you will be raining down about 4 times the photons on your girls!
 

BobCajun

Well-Known Member
It looks like series wiring to me. Like someone mentioned, the adjustment screw on the end of the driver may be turned down to 525 ma, unless you checked it. Is that how you dimmed it or by something external?
 

graying.geek

Well-Known Member
LEDs only pull as much as the forward voltage they are rated for. Your strips likely each draw around 24v each If you want more power you will either need to run the strips harder (not really recommended) or buy more of them. I would go for another 8 :)
Thanx, Twist. I'm not sure where you're getting the 24v from. Can you elucidate? I'm using the BXEB-L1120Z by the way. From the spec sheet the Fv at 1a should be ~50v, since the driver maxs out at 190v output, 190v / 4 strips should give me ~50v/strip. What's wrong with my calcs?

: said:
I would go for another 8 :)
Yeah, depending on the yield on this grow, I think I'll probably add another 4 strips for a total of 12.
 

graying.geek

Well-Known Member
It looks like series wiring to me. Like someone mentioned, the adjustment screw on the end of the driver may be turned down to 525 ma, unless you checked it. Is that how you dimmed it or by something external?
Thanx, Bob. Yeah, the A ver of these have a builtin actuator, but both are turned up to max. I've no external dimmer.
 

bakedPotatoe

Active Member
400w of strips give off the exact same amount of heat that 400w of cobs do. It's a misconception that they run cooler.

But having said that, I don't believe the OP has 400w running in his 2'x4' tent. It looks far too dim in there to me.
Wow,people are still stuck here on this..they might run a bit cooler but for you to match the same output you dont need the same wattage...
The reason they might run cooler is the ability to remove drivers from the grow room..
 
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