General help with cob build

dr.medecine

Well-Known Member
Hi all.

Sorry to crate a thread about this, searched for info but still uncertain and do not want to mess and neither can I afford it to be honest.

So I finally could afford to pull the trigger on a small space cob build but math is my weak side and must could not figure out AWG but Cobkit told me solid 18 gauge, build consist of HLG-120H-48A and 2x 3500k CLU048 1818 90CRI and might just swap to x3 or x4 1818's later on to improve efficiency a bit time will tell? Plan is to run actively cooled heat sinks ala CPU coolers cause aluminum heat sink is pricey here in north EU and if needed a fan on driver too, looking to maximize the parts soon to arrive.

It was a long time ago I build a light now and used individual constant current drivers back then so this is all new to me and from what I understand I will hook up the cobs in parallel and try to run a very short loop with driver located real close to lights and all that..

Not certain about final cable lengths but I will try to keep the loop real short about 2 max 3 foot if possible excluded whatever is already attacked to the driver itself? My biggest problem is finding the correct wire/cable (whatever you English natives call it), conversion tell me 18 AWG is 1.02mm diameter or 0.823mm2 cross section but I having a hard time to find it cheap and easily accessible here in north EU to receive it asap at least without crazy shipping costs added, possibly I am not sure what to search for?

I can find 20 AWG singles and 2x0,75 mm2 which is in between 18 and 19 AWG and those are very common but most 0.75mm are stranded, some solid core is available but they felt very stiff, next common size is 1.5mm2. Is there a big difference between 0.823mm2 (18 AWG) and 0.75mm2, I feel like I want to take full advantage of what I have saved up to and bought and already made some sacrifice in regards to efficiency by only affording 2x 1818's for the HLG-120 48A. I cannot afford building super efficient at least not for the moment, but electricity is expensive here and in the summers I have to fight heat too.

Cable/wire recommendations would be highly appreciated.
 

dr.medecine

Well-Known Member
Thanks, got a hold of Cobkits and asked him and got a replied that 18 awg is the way to go + I found this, a simple enough calculator for even me to understand some basics hehe:

http://www.calculator.net/voltage-drop-calculator.html?material=copper&wiresize=20.95&voltage=48&phase=dc&noofconductor=1&distance=2&distanceunit=feet&amperes=2.95&x=62&y=15

Yeah it will be a total of about 150w according to: https://cobkits.com/product/meanwell-hlg-120h-48a/ so understand it is not a lot of power but such a small space it should be enough for me.

Thanks.
 

qballizhere

Well-Known Member
You are looking for SOOW Portable Cord is recommended for use as portable electrical power and portable control wire cable. With its flexibility and resistance to the effects of abrasion, chemicals, weather and ozone, SOOW Portable Cord is excellent for heavy-duty cable service applications including industrial tools, portable lights, battery charters, and equipment that is typically exposed to oils, solvents, flame and grease. SOOW Portable Cord can also be used for ground tests and motor leads.

SOOW Portable Cord is rated to 600 volts and has a temperature range of –40ºC to 90ºC. These characteristics make SOOW Portable Cord an excellent choice for mitigating outdoor factors that would otherwise alter the performance of wire cable. For end users, this means greater flexibility for applications like push-button stations, fire alarm controls, and temperature control systems.

The letters SOOW denote particular properties of the cable:

S for Service
OO for Oil-resistant insulation and Oil-resistant jacket
W for Weather and Water resistance.

These properties make SOOW cable an extremely valuable component for any construction project, indoor or outdoor application where longevity is valued. SOOW Portable Cord that is UL-approved for permanent installation is often used in new construction and other applications where the wire will not need to be removed. This saves money at all levels of the construction process, from initial purchase through service invoice.
Also here is some info on wire gauge and the limits http://www.powerstream.com/Wire_Size.htm
 

Useless89

Member
Soooooo, I have a question. Im pretty new to the growing scene and trying to soak up as much info as I can. With that being said, what is a "cob" setup i mean obiouosly its a type of light but im not familiar with it that I know of and was super curious as to what it was
 

CobKits

Well-Known Member
a cob is a "Chip On Board", its a very efficient LED chip made up of hundreds of tiny leds
 

CobKits

Well-Known Member
5W - 500W. people like to run them at 40-75W

the softer you run them, the more efficient they are. the chips people are running at 40-75W are really rated for 100-300W.

average chip is between $12 (100W) and $35 (300W)

they are more efficient per watt than HPS at just about any wattage, and when run soft, some growers approach and/or top 2.0 g/W in yield
 

dr.medecine

Well-Known Member
qballizhere, thanks appreciate the explanation and good to know cause all these letters and stuff help when searching online. I found it hard to search yesterday but using these make it easier no doubt. Found your info here also so saved the pdf hehe..

http://www.ul.com/global/documents/corporate/aboutul/publications/newsletters/electricalconnections/july08.pdf

Found some really cheap 18 awg yesterday but in China and hook up wire, singles grr.. They were so cheap I could afford to buy a pack of 3m of each red and black and on printed ratings given, VW-1 (flame test I found out?), 200c, 600v but on the other hand I can read both rubber and silicon on jacket? I don´t trust this at all but so cheap I can use for low current testing if not good enough, need it asap so will still try to find 1 meter or so here where I live and I am not as lost as I where yesterday so thanks guys.

Useless89, look at Cobkits avatar and you can visually see exactly what he just explained to you in words. Might not help to understand the technology any better than what Cobkits just gave you but it will at least provide you with a image of a cob. The individual diodes are all in the LES (the yellow'ish stuff)
 

dr.medecine

Well-Known Member
hehe darn those pics that there one minute and gone the next, not sure who and where but I say one too but a video where someone hooked up to one of those lab variable power supply feeding amps up and down.
Again cannot find it now. :cuss:

Sharp support told me to count diodes in a mega zenigata trying to find what model I had but have no access to that or a constant current driver that go low enough to even look directly into it + very careful with my eye sight. :mrgreen:
 

wayward1

Member
Lol. I've tried. Lots of stranded 18 gauge. Lots of 22 solid. But no 18 solid in small quantity. Unless you have a link?
 

wayward1

Member
You clever dicks! Thankyou... you have just made my new years day so much easier to nurse my head. I had bought some .6mm wire thinking it was good to go until it came through the letter box and the delivery note specified it was bell wire. The Web page omitted that!
 

qballizhere

Well-Known Member
You clever dicks! Thankyou... you have just made my new years day so much easier to nurse my head. I had bought some .6mm wire thinking it was good to go until it came through the letter box and the delivery note specified it was bell wire. The Web page omitted that!
You will find that most of the 22-18 ga wire is for low voltage applications ie telephone and door bells. the 20 ga bell wire would of worked you could put a max of 6a if it was solid core and 3-5a stranded depending on how many strands it has.
 

wayward1

Member
I've got some and yes I'm sure it would work but I would never feel confident with it. I have also stripped down 1mm twin and earth cable used for house lighting in the UK but that is too thick unfortunately and have been tempted to sand the end down to .75mm to fit the bjb cob holder! Not a good idea.
 

Moflow

Well-Known Member
I've got some and yes I'm sure it would work but I would never feel confident with it. I have also stripped down 1mm twin and earth cable used for house lighting in the UK but that is too thick unfortunately and have been tempted to sand the end down to .75mm to fit the bjb cob holder! Not a good idea.
Why not..?.
Lol
 
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