LED Strips - thermal tape onto aluminum U channels - tape width? & wire gauge

K

kdt15

Active Member
I have led strips that are ~39mm wide and i see 20mm, 25mm, 30mm, 10mm width thermal tape for sale online.

should the tape be covering ALL of the width of the strips? does overlap or hang-off matter? (2 20mm tape will have 1mm of overlap, or hang off edge)

lastly, these strips have screw holes on the edges of the lengths, so its mainly the center of the led strips that are non-holed. should i tape around it or just tape over it anyways (not going to really be using screw holes) - will it affect heat transfer or something?

theres also 0.25mm vs 0.15mm thickness - will this matter for growing?

~~~~~~~~
wire gauge - solidcore, stranded, etc

using HLG-480H-C1400A constant current (can fit 6-7 of the strips @46v each for ~300-345V overall) wiring in series, does my wire gauge matter?

research tells me it depends on the amount of current flowing through, but if im using constant current for strips that are rated at 1.12A, thats pretty tiny right?

could i just use 18g solid core and be done with it?

on amz, can only find 1 color (usually black) so do people still recommend using black/red for +/- or does this not matter much in the end?

PS: what alarms me is that most wires are rated 300V but im possibly drawing 300-345v (6 vs 7 strips). i understand in series that voltage drops each time so thats not the issue, but the driver connection will have that high 300-345v wiring before the first strip right? will this be a problem?

https://www.amazon.com/Shaxon-SO18-100BK-Solid-Copper-100-Feet/dp/B00IN838Z0/ref=sr_1_3?s=lamps-light&ie=UTF8&qid=1519418935&sr=1-3&refinements=p_n_feature_keywords_browse-bin:3605500011&th=1
 
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thetr33man

thetr33man

Well-Known Member
I made a strip light recently using 20mm tape with 24mm strip, worked a charm. I dont think the tape needs to cover the whole bottom of the strip. Id use 30mm tape probably but havent used those specific strips, someone with more experience will come along... Why not use a few lower voltage drivers? 1 driver = single point of failure and wont save you much money.
 
K

kdt15

Active Member
Hmm not sure, was just what was recommended when I planned it out. I have 14 of those, should have a few left over for this specific room just in case
 
K

kdt15

Active Member
nc208 said:
@kdt15
Yes your tape should be covering the whole width of the strip, it is helping transfer heat to the heatsink.
If your load is going to be over 300v why would you not use a wire thats then rated for 600v?
Click to expand...
im bad at physics :( barely caught it when i realized wires had voltage ratings.

found something 600v but its "parallel" does that mean its for parallel connetions only?

https://www.amazon.com/BNTECHGO-Flexible-Conductor-Resistant-Extension/dp/B0785FJNBJ/ref=sr_1_3?ie=UTF8&qid=1519436335&sr=8-3&keywords=600v+18g+wire

having a lot of trouble finding 600v 18g solid wire
 
Last edited:
nc208

nc208

Well-Known Member
kdt15 said:
im bad at physics :( barely caught it when i realized wires had voltage ratings.

found something 600v but its "parallel" does that mean its for parallel connetions only?

https://www.amazon.com/BNTECHGO-Flexible-Conductor-Resistant-Extension/dp/B0785FJNBJ/ref=sr_1_3?ie=UTF8&qid=1519436335&sr=8-3&keywords=600v+18g+wire

having a lot of trouble finding 600v 18g solid wire
Click to expand...
No the parallel means it's 2 pieces of wire instead of 1.
Does it have to be solid core? Can you tin the tips for your application?
 
noodle-led

noodle-led

Well-Known Member
You can see how heat spreads on the strips in the thread I posted on Bridgelux EB thermals but 39mm sounds like Samsung strips. The Samsungs go more to the edge so I'd go with two lines of 20mm, where one 20mm is fine for EB strips (24mm wide) because the EBs are centered. Don't worry about going over the edge, or cutting out the screw holes. It will be sticky but it's not going to do anything or cause any problems. Some bugs might eventually meet their doom there?

As far as thickness, 0.25mm vs 0.15mm, the difference in thickness is to better adhere to rougher surfaces. Since both your surfaces will be smooth, the thinner adhesive transfers heat marginally better and is probably cheaper.

I've also not seen 600V 18AWG solid core. 600V is pretty uncommon voltage so things start to get a little rare.
 
K

kdt15

Active Member
nc208 said:
No the parallel means it's 2 pieces of wire instead of 1.
Does it have to be solid core? Can you tin the tips for your application?
Click to expand...
thanks, the parallel terminology was very confusing!

i guess not, it was just a recommendation i read online (to use solid). by tin, i presume you mean to soldering them together so they dont fray? Sure, if its simpler/better/more money saved

Is there a downside to solid core? (aside from seemingly being hard to find, and possibly more expensive?)
 
K

kdt15

Active Member
noodle-led said:
You can see how heat spreads on the strips in the thread I posted on Bridgelux EB thermals but 39mm sounds like Samsung strips. The Samsungs go more to the edge so I'd go with two lines of 20mm, where one 20mm is fine for EB strips (24mm wide) because the EBs are centered. Don't worry about going over the edge, or cutting out the screw holes. It will be sticky but it's not going to do anything or cause any problems. Some bugs might eventually meet their doom there?

As far as thickness, 0.25mm vs 0.15mm, the difference in thickness is to better adhere to rougher surfaces. Since both your surfaces will be smooth, the thinner adhesive transfers heat marginally better and is probably cheaper.

I've also not seen 600V 18AWG solid core. 600V is pretty uncommon voltage so things start to get a little rare.
Click to expand...
thanks noodle! yes it is the samsung F series strips, you got your info down to a high level :)

Do the samsung strips diodes really go more to the edge? they seem pretty centered to me (LINK samsung f series strip kinda looks like this)

i have shaky hands so i hope my OCD doesnt go crazy with slightly overlapped tape if i dont align it perfectly >:( (actually, does overlapped tape cause some weird thermal transfer issue?)

I could also go with a 30mm tape, leaving 4.5mm each direction on the sides not taped.

LAstly, instead of using aluminum square tubes to mount my u channels to, i am going with a larger-diameter PVC to save a little bit of $. Do you see any issues with this? just going to screw the u channels into the PVC as a bracket like a ladder, with the strips/channels being the rungs.
 
noodle-led

noodle-led

Well-Known Member
Oh see I can recall one thing off the top of my head (the exact width of the strips) but for some reason I remembered the LEDs being more toward the outside.

I'm with you, I would have a heck of a time trying to lay down 2x side by side 20mm pieces of tape and not have them overlap. I actually had a whole roll of 10mm and bought 20mm tape to do my 24mm strips because I didn't want to have to worry about it. You definitely don't want it to overlap, it will create a gap you won't be able to compress out. Because there is so much area to transfer the heat, it won't be a deal-killer, but you will have localized higher temps. When I did my testing there was one section in one of the tests that was clearly a hot spot (2-3C hotter) and when I pulled it off the aluminum, it had a small wrinkle in the tape, so flatness is key.. I think 30mm would be ok, even with 10mm on my strips I'd say they still had 95% of the effectiveness. Even Cree in their thermal design guidelines say there's almost no benefit in going further than 10mm from the LED (5mm from each side).

As far as the ends, there's no reason to use aluminum for the ends so PVC is fine if you can build something that will hold your u-channel easily. It doesn't dissipate any significant amount of heat. In my build I am using 1/2"x1/2"x1/16" angle aluminum which is pretty cheap as well because the whole 28"x24" fixture only weighs 5.25lbs, with 2.5lbs being the driver.
 
K

kdt15

Active Member
noodle-led said:
Oh see I can recall one thing off the top of my head (the exact width of the strips) but for some reason I remembered the LEDs being more toward the outside.

I'm with you, I would have a heck of a time trying to lay down 2x side by side 20mm pieces of tape and not have them overlap. I actually had a whole roll of 10mm and bought 20mm tape to do my 24mm strips because I didn't want to have to worry about it. You definitely don't want it to overlap, it will create a gap you won't be able to compress out. Because there is so much area to transfer the heat, it won't be a deal-killer, but you will have localized higher temps. When I did my testing there was one section in one of the tests that was clearly a hot spot (2-3C hotter) and when I pulled it off the aluminum, it had a small wrinkle in the tape, so flatness is key.. I think 30mm would be ok, even with 10mm on my strips I'd say they still had 95% of the effectiveness. Even Cree in their thermal design guidelines say there's almost no benefit in going further than 10mm from the LED (5mm from each side).

As far as the ends, there's no reason to use aluminum for the ends so PVC is fine if you can build something that will hold your u-channel easily. It doesn't dissipate any significant amount of heat. In my build I am using 1/2"x1/2"x1/16" angle aluminum which is pretty cheap as well because the whole 28"x24" fixture only weighs 5.25lbs, with 2.5lbs being the driver.
Click to expand...
awesome! to save mental stress, might go with a single 25mm or 30mm down the middle (need to measure again) after your thermal testing evidence after i measure the width of the paired diodes and give 5mm clearance per side.

surprised to see that you had high ~95% effectiveness on just 10mm on your 24mm strip!

for your driver, this is something i have not really figured out what to do (where to place them). sounds like you are just placing your driver somewhere to the side or on top? (i presume your fixture is kinda like a ladder/rectangle, so not much space to rest a driver that gets very hit).

was just going to attach it to the side of our SCROG shelves away from any plants for my current plan.
 
P

PurpleBuz

Well-Known Member
kdt15 said:
I have led strips that are ~39mm wide and i see 20mm, 25mm, 30mm, 10mm width thermal tape for sale online.

should the tape be covering ALL of the width of the strips? does overlap or hang-off matter? (2 20mm tape will have 1mm of overlap, or hang off edge)

lastly, these strips have screw holes on the edges of the lengths, so its mainly the center of the led strips that are non-holed. should i tape around it or just tape over it anyways (not going to really be using screw holes) - will it affect heat transfer or something?

theres also 0.25mm vs 0.15mm thickness - will this matter for growing?

~~~~~~~~
wire gauge - solidcore, stranded, etc

using HLG-480H-C1400A constant current (can fit 6-7 of the strips @46v each for ~300-345V overall) wiring in series, does my wire gauge matter?
Click to expand...
Consider grouping your strips into parallel serial combos and use one of the HLG constant voltage drivers such as the HLG-320h-48a or the HLG-480H-48a That will lower the open voltage on the circuit significantly. Personally I stay away from constant current drivers once the open voltage gets close to 300.
 
Buck5050

Buck5050

Well-Known Member
I went with 15mmx25mx.25mm Aikenuo Thermal Double Side tape for my EB gen2 and after a month of hanging upside down the edges look like thisIMG_20180221_125714.jpg

So I remodeled with just paste and screws. Never again will I use the double sided tape. These are run at 75% max current at 18/6 hours and started drooping about 2 weeks into that schedule.
 
K

kdt15

Active Member
PurpleBuz said:
Consider grouping your strips into parallel serial combos and use one of the HLG constant voltage drivers such as the HLG-320h-48a or the HLG-480H-48a That will lower the open voltage on the circuit significantly. Personally I stay away from constant current drivers once the open voltage gets close to 300.
Click to expand...
i must be unaware of the danger, what is the issue of constant current with 300v?
 
K

kdt15

Active Member
Buck5050 said:
I went with 15mmx25mx.25mm Aikenuo Thermal Double Side tape for my EB gen2 and after a month of hanging upside down the edges look like thisView attachment 4095651

So I remodeled with just paste and screws. Never again will I use the double sided tape. These are run at 75% max current at 18/6 hours and started drooping about 2 weeks into that schedule.
Click to expand...
wow thats terrible! that brand supposedly is good too :( just started coming off an edge and lost stickyness?
 
Buck5050

Buck5050

Well-Known Member
The tape is really good stuff but it was a royal pain in the ass to separate the part of the strip that actually bonded. Getting the tape off the aluminum is not gonna happen with out a wire wheel on an electric grinder. Use the tape if your can get it to bond fully and plan on never removing the strips from the heatsink. Using paste and self drilling screws didn't take much more effort to install.
 
D

Dave455

Well-Known Member
kdt15 said:
thanks noodle! yes it is the samsung F series strips, you got your info down to a high level :)

Do the samsung strips diodes really go more to the edge? they seem pretty centered to me (LINK samsung f series strip kinda looks like this)

i have shaky hands so i hope my OCD doesnt go crazy with slightly overlapped tape if i dont align it perfectly >:( (actually, does overlapped tape cause some weird thermal transfer issue?)

I could also go with a 30mm tape, leaving 4.5mm each direction on the sides not taped.

LAstly, instead of using aluminum square tubes to mount my u channels to, i am going with a larger-diameter PVC to save a little bit of $. Do you see any issues with this? just going to screw the u channels into the PVC as a bracket like a ladder, with the strips/channels being the rungs.
Click to expand...
I shake some also....Best cure I found couple shots of Jim Beam !
 
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