Some DIY LED questions....

nfhiggs

Well-Known Member
but i will have to test to see the optimal gauge and layout for the part that parallels the current to each strip....
I generally recommend 14g for currents above 10 amps.
What good is 12 awg going to do for you when the leads from the driver is 14 awg on the 320.
You make a good point. There really is no need to go larger than what comes out of the driver - unless the run is going to be very long.
 

IggyP

Active Member
No, the resistance of the wire nut is not .0045 ohms. The resistance of the wire is .0049. The wire, with a wire nut inserted in the middle is .0045, so the the wire nut reduced resistance by .0004 ohms. Obviously that's not possible, the discrepancy is a minor difference in wire length.

Dumb test, it's far better to test a connector under load. To measure the voltage drop across a connection (or wire), put a volt meter across it and power up the circuit!
right....i assumed that was implied...
ive done the basic voltage test with the current setup already, which is how we got here... but more will be coming asap once i have more materials to compare....

What good is 12 awg going to do for you when the leads from the driver is 14 awg on the 320. My 240 leads are only 17 awg. Every connection you make is another possible electrical loss and failure point in your build.
And I just have to ask this, What the heck is all that plant material laying everywhere with a half dead plant sitting under your light ?
thanks for pointing out about the 14awg lead.....i hadnt looked into that so far, but im not sure it will make any diff or not...
the potential reason to use 12 wire, would be....not to push more current thru, but to minimize resistance/voltage drop over a 15-20ft distance....from between the "remote mounted driver" to the LED array....once that part comes into play....

part of the dilemma with this stage, is either way it will face a resistance but which path to minimize is still unclear....

more wire = more resistance
more connections= more resistance

i sat here looking at a block connector bar for a while.....then i thought, hey it would be even better if the terminals were farther apart lol....perhaps even if each terminal outlets were connected and set to custom distances from each other......which of course is what i have done essentially.....

atm, the question in my head is still the same....which is the most efficient improve path?......for example, keeping it clean, heres a few possibilities im pondering on....

#1. i could run the long run from the remote mounted driver with the 12 or 14 wire>> to a small terminal block mounted to the light which branches to 2-3 leads...from there 12 or 14 wire could take each of those to a section of the strips, which would be connected by push in connects larger gauge and then of course with the 18 ran from push in connects to the strips...so in this case instead of 23 in a sketchy 16awg "line", 7-8 each from the 3 shorter larger gauge lines.....still basically parallel tho.......to me the question there is how much is needed....2 leads, 3 leads? what size wire etc....idk if anyone can tell me that either, but that is my thoughts so far...

#2. mount one huge terminal block, and run long 18 wire runs to every strip from there

#3. mount a few terminal blocks, to allow for shorter 18awg runs....rest same idea tho

#4. exactly like it is now, with better wire

i have to admit i am leaning toward the first one so far, but i really need to do tests and i dont even have a 20amp multimeter atm! so pretty limited.....its all on the way tho....


the room?? lol....i must argue that plant is half alive! how many lbs i can haz??

lol......gotta keep a sense of humor in life....its very important even on the internet ;P

this room hasnt really been used for a couple years but i am reviving it as we go....you will see cleaning up and improves lol...atm that is just a chemdog #3 i got on the bench so there can be something photosynthesizing some photons....it will eventually be recloned and killed so im only focus to keep it alive atm...

i want to point out that i would not be able to bloom in here in a summer enviro without a tech like this, so all your inputs can really help to make a good diff here......

im not fully stoked on a braggadocios styling, i rather to keep a focus to the science and projects...but at least i will mention i am beyond the hobby realm for some good bit of time... i should be able to give this a good solid test for real....pretty cool but i can admit i feel more like a beginner than i have for a long time lol. fun stuff..

planning to run a small variety of lines to see how diff ones react in this new setup....including some light sensitive um...probly just the chemdog 4 and D....but there will be kush and some fpog, couple light lovers as well....chomping the bit pretty hard lol, but its a good time to go over these numbers and the build logics.

peace!
Iggy
 

nfhiggs

Well-Known Member
mount a few terminal blocks, to allow for shorter 18awg runs....rest same idea tho
Whats the longest the wire would be for a single terminal block mounted in the center of the fixture end? Two feet?

You have to keep in mind that voltage drop of the wire is dependent on amperage as well and gauge and length. 18g is only one step smaller from the 16g (about twice the resistance per foot), but you're running more than 95% less current (to each individual strip), and over a shorter length. So where you had 0.6 v drop and 8W power loss with 16g/13A/8 ft, with the 18g, if your longest wire is 2 feet, that's a voltage drop of less than .03v and a power loss of less than 15 mW (0.015 watts) at 525 mA.
 

IggyP

Active Member
yeah ultimately its the amps im more concerned about....that seems most whats gonna squeeze every lumen out and keep the strips running max output on these drivers....i know voltage drops over longer runs which i wanna minimize....but after a few quick reads it seems the amps that are more effected by ohms anyway?
Simple_Ohms_Law.jpg
my assumption is a "little bit of flux" in the voltage shouldnt have to effect the current?....but the way it is right now, i guess it is too much drop so it is effecting the amps or whatever for whatever reason...(remember even manually dimming voltage was dropping amps immediately)

something is blocking flow i can tell that much even with a light meter atm, just cant dig in to troubleshooting till mail comes...

its helping me clear my head thank you for the data and inputs....hopefully once the rest of the gear gets here it will be a couple quick tests and a clear path instead of multiple tries...totally rewiring.....i dont even wanna start the second one till i know what im looking at here in terms of spacing and such...
 

1212ham

Well-Known Member
my assumption is a "little bit of flux" in the voltage shouldnt have to effect the current?....but the way it is right now, i guess it is too much drop so it is effecting the amps or whatever for whatever reason...(remember even manually dimming voltage was dropping amps immediately)
Dimming or limiting voltage will reduce amperage, limiting amperage will reduce voltage. Volts, amps and resistance are directly related. Search "Ohms Law", it's absolutely fundamental to understanding basic dc circuits.
 

IggyP

Active Member
Dimming or limiting voltage will reduce amperage, limiting amperage will reduce voltage. Volts, amps and resistance are directly related. Search "Ohms Law", it's absolutely fundamental to understanding basic dc circuits.
i think where i got confused on this is with these CC+CV in one drivers....

i considered that perhaps the reason for the voltage drop was the driver kicking into CC mode to make up for low amps....but turning down the amps, did not increase voltage...so that was confusing....

i am tending to think of this in part like an AC wall socket that may flux actually from approx 110 to 120v, yet average appliances can still pull the current they need without getting that similar "reduction" in current....might not have to do with anything lol, but like i say its a learning adventure...

i am trying to consider this terminal splitter route....its less work for one thing lol.....der....any links of good ones? at a glance i see alot of separated terminals and 12v limitations..couple 8way ones with mixed reviews etc....the wires need to solidly stay in at least i know that lol...

less work plus higgs comment about the lower current in the 18awg lines giving less resistance is a power logic...that really makes sense and might push me that direction...i still intend to do these basic tests for us tho and have not decided yet.....may end up with a few variations, but equal efficient output has to be king in all.

even with the push connectors tho, if i can even up the output its not THAT much more work and the whole end bit could be covered by another channel for better safety and aesthetic appeal....

true field comparisons are perhaps the only way to know so um.....yeah i guess one first "easiest" trial would be getting a few 4way push connects and splitting that long line up into 3 larger gauge jogs..

i can also test the resistance of this tinned 16awg and perhaps the result will be alarming enough to tell us something without the solid copper in hand idk...
 

nfhiggs

Well-Known Member
but turning down the amps, did not increase voltage
Not sure why you would expect that. Voltage and current are always directly related. One goes up because the other goes up. They ALWAYS move together. Just turn both adjustments fully clockwise.

i am trying to consider this terminal splitter route....its less work for one thing lol.....der....any links of good ones? at a glance i see alot of separated terminals and 12v limitations..couple 8way ones with mixed reviews etc....the wires need to solidly stay in at least i know that lol...
Did you look at the ones I linked?
Terminal block
Jumper strips

i can also test the resistance of this tinned 16awg and perhaps the result will be alarming enough to tell us something without the solid copper in hand idk..
You're not going to get accurate measurement of wire resistance without a very expensive bench meter. Cheap handheld meters will not give any meaningful results.
 

IggyP

Active Member
Not sure why you would expect that. Voltage and current are always directly related. One goes up because the other goes up. They ALWAYS move together. Just turn both adjustments fully clockwise.


Did you look at the ones I linked?
Terminal block
Jumper strips


You're not going to get accurate measurement of wire resistance without a very expensive bench meter. Cheap handheld meters will not give any meaningful results.
that isnt how i understand CC drivers work tho...."constant current" which it pulls from the voltage if needed...am i wrong?

regarding testing, that maybe some true...we can still see big differences tho.....perhaps not an exact # on a 6inch piece or wire or something but this meter should be close within a few percent for voltage tests etc...

didnt realize you already linked terminals, my bad, ill go read up thank you..
 

1212ham

Well-Known Member
that isnt how i understand CC drivers work tho...."constant current" which it pulls from the voltage if needed...am i wrong?
.
You just don't understand at all. Did you read about Ohm's Law?
 
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IggyP

Active Member
that isnt how i understand CC drivers work tho...."constant current" which it pulls from the voltage if needed...am i wrong?
no iggy you are not wrong...lol....i can link if anyone besides me is willing to learn, but this is getting tiresome....know it all pissing contests cmon guys we can do better....
 

IggyP

Active Member
ok, just yanked that parallel line off the array for some tests to see better what in the actual fck.....

mind you these tests are without any current being drawn, but still interesting..

ive tested the plain 16awg "tinned wire" i was suspect of....zero voltage drop over 12-15ft or so...

with the 50 push in connectors on the "4ft" array= drop of 1.2volts
with current running thru, it drops about 1 extra volt....(approx 2.2v)

pretty clear proof and pudding and all that right there is one thing i needed to see...

i do not suspect using thicker wire will make any diff of that, so this may officially kill the push in connector approach...

it is all pretty interesting to me....i mean....i have built a house and wired it before....wired countless grow rooms....but terminal block connectors, wagos, dcv etc i just dont have any experience with....
 
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nfhiggs

Well-Known Member
that isnt how i understand CC drivers work tho...."constant current" which it pulls from the voltage if needed...am i wrong?
Yes, your understanding is not correct. Voltage and Current ALWAYS move in the same direction. As the LEDs warm up, their Vf drops, and they pull more current. The CC driver REDUCES the output voltage and that pulls the current back down with it. If current goes below the setpoint, the driver will increase the voltage to pull the current up.

no iggy you are not wrong...lol....i can link if anyone besides me is willing to learn, but this is getting tiresome....know it all pissing contests cmon guys we can do better....
Link it if you like, its either incorrect or you are interpreting it wrong.

As I said, with the number of strips you have and the driver, simply put both adjustments full clockwise to get the full output from the driver.
 

IggyP

Active Member
Yes, your understanding is not correct. Voltage and Current ALWAYS move in the same direction. As the LEDs warm up, their Vf drops, and they pull more current. The CC driver REDUCES the output voltage and that pulls the current back down with it. If current goes below the setpoint, the driver will increase the voltage to pull the current up.


Link it if you like, its either incorrect or you are interpreting it wrong.

As I said, with the number of strips you have and the driver, simply put both adjustments full clockwise to get the full output from the driver.
-regardless of voltage dimming setting, i could not get it above 22.5dcv with everything attached to the wagos...btw it maxes out resistance, BEFORE the dimmer is turned all the way up...so im assuming it will not put out anything higher unless its rewired....

-dam....you are right tho, about me being wrong lol....i misunderstood it, but it still is a very good vid on this topic so heres the link...its around 18:30 where i misunderstood

still sounds like a contradiction of sorts tho... even this post u made, probly does make sense but u say as leds warm up "V drops and A goes up"....which would seem to contradict, "Voltage and Current ALWAYS move in the same direction."

its a complicated subject to learn at best...which i am trying to crunch parts of in short order...i appreciate those who are willing to try to help and learn tho...

from after all this part, i can see it is at least 1volt lost to bad wiring which is all im trying to regain really...in the interest of consistant output mainly....hopefully the terminal blocks will make that big a diff...i have some on the way
 

nfhiggs

Well-Known Member
V drops and A goes up
Actually I said "Vf drops" - that's not the same as the drivers output voltage. Vf is the physical property of the diode, similar to resistance, that determines how much current flows when a particular voltage is applied. And Vf changes inversely with temperature. So "Vf drop" in this context really just means that the LED's effective resistance has dropped. Ohm's law tells us that if resistance decreases, then current increases. In order to reduce the current (to keep it constant), the driver has to reduce the output voltage the bring the current down.

I agree it can be confusing at times.
 

nfhiggs

Well-Known Member
i could not get it above 22.5dcv
Actually - for your target amperage of 525 mA per strip, 22.5 V is right on target. My F-strip fixture hits 665 mA per strip at 22.7v (measured at the driver). And if you look at the Samsung simulator, they will only need 22.1v (typical) for 525 mA. If you look at the min and max Vf values they are 21.1v and 23.3v - so you are actually sitting right in the middle at 21.9V. Here is a link to the Samsung simulator page:
Samsung Engine Calculator


So to put it simply, there is no real problem here, your setup is working exactly as it should. IMO, the only thing you really need to do is get rid of all those Wago connectors - and that's mainly just a cosmetic improvement.
 

IggyP

Active Member
the problem i dont like is the strips do not output evenly....farther from the driver gets dimmer due to the Vdrop...in my ignorance, i didnt think a slightly lower voltage would effect the amps as much like that, or that the connectors would do that as notably.. makes perfect sense in hindsight tho lol...

its like 25% dimmer by the end...

so still same problem basically for me... even if the output is "proper", uneven resistance pushes the amps more toward the front...

the terminal bars should fix that tho sounds like....even if it does it by "dimming" the front strips, it still needs to happen imho...then i can double check on the strip placements...

should still be nice and bright, i was sort of hoping to pull all the numbers up lol, instead of averaging them...but probly doesnt even need that...with quick footcandle check, looks like roughly 18inches or so i will have in usable depth for my scrogs, which is more than enough...
 

nfhiggs

Well-Known Member
the problem i dont like is the strips do not output evenly....farther from the driver gets dimmer due to the Vdrop
Yeah, that's due to the long chain of connectors. You get the same effect if you connect strips end to end. Thats why I chose to use a distribution block.
 
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