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Where is my other 100 watts?
Posted: Mon Nov 05, 2018 6:42 pm
by ubuntuuser
I put together the following:
10x SI-B8U261560WW
1x HLG-320H-24B
1x 100k Pot =
Code: Select all
https://www.amazon.com/gp/product/B07BMZ1FHJ/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
16awg is ran for about 6ft from the driver to the first row of LEDS. After that I dropped down to 18awg to the rest of the strips.
According to my DVM I am setting at 23.1-2V with the pot spun all the way up.
According to my killawatt I am setting at 238 watts.
Where have I gone wrong? I thought this would easily pull 300w from the wall.
Re: Where is my othere 100 watts?
Posted: Mon Nov 05, 2018 6:46 pm
by Shimbob
Remove the pot and measure again?
Re: Where is my othere 100 watts?
Posted: Mon Nov 05, 2018 6:48 pm
by ubuntuuser
Shimbob wrote: ↑Mon Nov 05, 2018 6:46 pm
Remove the pot and measure again?
No change after doing that.
Re: Where is my other 100 watts?
Posted: Mon Nov 05, 2018 7:10 pm
by Shimbob
Strange. Can you hook up an ammeter?
Measure the voltage at the last strip? Voltage loss due to the wire comes to mind but you're measuring 23v which seems well within the tolerances.
Re: Where is my other 100 watts?
Posted: Mon Nov 05, 2018 7:25 pm
by ubuntuuser
Shimbob wrote: ↑Mon Nov 05, 2018 7:10 pm
Strange. Can you hook up an ammeter?
Measure the voltage at the last strip? Voltage loss due to the wire comes to mind but you're measuring 23v which seems well within the tolerances.
I am showing 23v when I measure from the out terminals of the first strip. There is a slight and steady decline as I go down until the last strip where it shows 22.4v. So I am loosing .6v over the entire run. I did not expect to see that.
Re: Where is my other 100 watts?
Posted: Mon Nov 05, 2018 8:37 pm
by Shimbob
What size wire did you use? That's a sharp drop for such a short run. Also measure at the immediate output of the driver.
If it is indeed too small wire the proper fix would be to redo everything with thicker wire.
Another possible fix may be to move one of the supply wires to the other side of the panel, ie disconnect the red from the right side and connect it to the left side. This will balance out the wire losses and might work but it's not the perfect solution if the wires are indeed too small.
Re: Where is my other 100 watts?
Posted: Mon Nov 05, 2018 8:58 pm
by ubuntuuser
Shimbob wrote: ↑Mon Nov 05, 2018 8:37 pm
What size wire did you use? That's a sharp drop for such a short run. Also measure at the immediate output of the driver.
If it is indeed too small wire the proper fix would be to redo everything with thicker wire.
Another possible fix may be to move one of the supply wires to the other side of the panel, ie disconnect the red from the right side and connect it to the left side. This will balance out the wire losses and might work but it's not the perfect solution if the wires are indeed too small.
16awg for about 5ft from the driver to the first row of LEDs. Then I dropped down to 18awg. This is all stranded wire.
Re: Where is my other 100 watts?
Posted: Mon Nov 05, 2018 9:03 pm
by ubuntuuser
I am showing 24.1 on the driver leads. I am loosing .9v between my soldered connection and the 5ft run of wire. Is this to long of a run for this size wire?
Re: Where is my other 100 watts?
Posted: Mon Nov 05, 2018 9:14 pm
by Shimbob
Oh, you mentioned wires in op too.
Thats a lot of loss. 16awg is just a very small wire to carry that much current. My suggestion is to replace it with 12awg.
Re: Where is my other 100 watts?
Posted: Mon Nov 05, 2018 9:35 pm
by ubuntuuser
Shimbob wrote: ↑Mon Nov 05, 2018 9:14 pm
Oh, you mentioned wires in op too.
Thats a lot of loss. 16awg is just a very small wire to carry that much current. My suggestion is to replace it with 12awg.
According to this calculator:
http://www.solar-wind.co.uk/cable-sizing-DC-cables.html
I need to bump up to 10awg to maintain a 1% loss.