Indoor Northern Grow Lights - Test Team Home - DIY build and Grow

[Ripper]

@BigSm0
SST120 is rated for 50 watts so that it stays cool enough to safely touch even if there is no air movement in the grow space.
If you run them at 75 watts then we are at 0.9 C/W and 45Watts of heat so about 40C temp increase over ambient. Assuming grow space is at 30C, add 40C , your heatsinks would be at 70C, which is fine for the LED.
All the calculations above assume you have no air movement. With air movement you should be able to run 60W-75W on SST120.
I recommended Ripper this driver so that he can add extra power if needed.


Great looking build @Ripper
You can add a ground wire from junction box and connect it to the frame. Not sure how much it helps but I always add one to make sure frame is safe to touch.
Looking forward to seeing your lamp in action with reflectors. It will work awesome.
After mounting in grow space let us know at what power does the heatsink become too hot to touch.

Thank you for the kind words and advice. I will add the ground wire tonight. I am putting my tents up this weekend and will be checking temps as you suggested. I will update you here.

 

[BigSm0]

@BigSm0
SST120 is rated for 50 watts so that it stays cool enough to safely touch even if there is no air movement in the grow space.
If you run them at 75 watts then we are at 0.9 C/W and 45Watts of heat so about 40C temp increase over ambient. Assuming grow space is at 30C, add 40C , your heatsinks would be at 70C, which is fine for the LED.
All the calculations above assume you have no air movement. With air movement you should be able to run 60W-75W on SST120.
I recommended Ripper this driver so that he can add extra power if needed.


Great looking build @Ripper
You can add a ground wire from junction box and connect it to the frame. Not sure how much it helps but I always add one to make sure frame is safe to touch.
Looking forward to seeing your lamp in action with reflectors. It will work awesome.
After mounting in grow space let us know at what power does the heatsink become too hot to touch.

Thank you for the explanation I actually got the 50w max from your website. Seeing 75 watts is acceptable now I may switch from the 140's to 120's in future builds. But then again the 1050ma driver should hold 5 citi's safely. 6 may be pushing it a little but the increased efficiency on the lower ma driver and reasonably priced cobs sounds like a winner to me. Softer run but more of them

 

[HLG1]

50W is my recommendation for SST120. I like to be very conservative with my recommendations.
Lets see if @Ripper says 75W is acceptable

5 citi in series may not be a good idea.
Only 4 in series as 1812 and 1818 are 50V-54V and 5x would exceed the Ideal holder 250V rating.


You can do 5 or 6 1212 as they are 36V and 6x would be within the 250V ideal holder rating.

 

[HLG1]

@Ripper May i add your design to my Gallery

https://goo.gl/photos/9b5Fp3qwUHxEJZeNA

 

[Ripper]

@Ripper May i add your design to my Gallery

https://goo.gl/photos/9b5Fp3qwUHxEJZeNA

View attachment 631909

I would be honored to have it added. .. when it is in the tent I will get you n even better picture with the reflectors on it

 

[HLG1]

I ran my twin cob at 1.5 amps. Around 75 watts per cob. 120mm heatsink and 1818 COB.
There are 2x 120mm fan for air circulation in this Herb tent.
The left Heatsink was around 44C and the right was 52C. I assume right is slightly higher as there is more air movement on left.
These heatsink temps are really cool.

 

[GoAuto6]

how many cobs can be put on this?

MEAN WELL [PowerNex] NEW HLG-600H-15 15V 36A 540W Single Output LED Power Supply
http://www.ebay.com/itm/MEAN-WELL-PowerNex-NEW-HLG-600H-15-15V-36A-540W-Single-Output-LED-Power-Supply/252522220470?_trksid=p2047675.c100009.m1982&_trkparms=aid=888007&algo=DISC.MBE&ao=1&asc=20131227121020&meid=5e1bacb3423242c8b12c2957f7d6bea5&pid=100009&rk=1&rkt=1&sd=252496345762


would it run 4 of these?
http://www.ebay.com/itm/Smart-IC-Le...8df3ae0&pid=100005&rk=4&rkt=6&sd=232074361288

 

[BigSm0]

how many cobs can be put on this?

MEAN WELL [PowerNex] NEW HLG-600H-15 15V 36A 540W Single Output LED Power Supply
http://www.ebay.com/itm/MEAN-WELL-PowerNex-NEW-HLG-600H-15-15V-36A-540W-Single-Output-LED-Power-Supply/252522220470?_trksid=p2047675.c100009.m1982&_trkparms=aid=888007&algo=DISC.MBE&ao=1&asc=20131227121020&meid=5e1bacb3423242c8b12c2957f7d6bea5&pid=100009&rk=1&rkt=1&sd=252496345762

None. Check the YouTube DIY basics video

 

[The Elvis]

how many cobs can be put on this?

MEAN WELL [PowerNex] NEW HLG-600H-15 15V 36A 540W Single Output LED Power Supply
http://www.ebay.com/itm/MEAN-WELL-PowerNex-NEW-HLG-600H-15-15V-36A-540W-Single-Output-LED-Power-Supply/252522220470?_trksid=p2047675.c100009.m1982&_trkparms=aid=888007&algo=DISC.MBE&ao=1&asc=20131227121020&meid=5e1bacb3423242c8b12c2957f7d6bea5&pid=100009&rk=1&rkt=1&sd=252496345762

Ga your gonna want a B and not A . with the B you can turn up and down with a pentameter. If you go with a A driver you will need to use a small screw driver to turn the cobs down..

thats 600 at 15 .. Look into the cobs you want to play with first and then decide on a driver to power the cobs you like..

 

[BigSm0]

Maybe in 5 years or so when cobs are 20 inches in diameter. But that's one powerful driver and way to much for the little things we play with. Growmau5 has some good videos on driver matching. Usually drivers are kept below 2100ma or 2.1 amps.