How Many Pixels Per 115V Outlet

[munu]

I bought a few LRS-350-12 PSUs thinking I will run 12V pixels to minimize PI (based on what I read on this forum and other places). Then I read the current 5V vs 12V post which mentioned power consumption. So I started doing more research. MeanWell has the LRS-350-5 and LRS-350-12 with both consuming 6.8A on 115V. They can deliver the following amparage

LRS-350-5 outputs 60A
LRS-350-12 outputs 29A

So the maximum number of pixels I can run on one such PSU is (assuming 60mA)

LRS-350-5 can do 60A/0.06A=1000 pixels
LRS-350-12 can do 29A/0.06A=483 pixels

Just for double checking I also looked at the wattage

5V pixels: 15W/50 = 0.3W -> 350W/0.3W = 1166 pixels
12V pixels: 27W/50 = 0.54W ->350W/0.54W = 648 pixels

So it seems I can get twice as many pixels with 5V vs 12V. That's to be expected. But at 6.8A on 115V I can only have two such PSUs on one 115V circuit. That's 2000 5V pixels or 1000 12V pixels. I understand this is at full blast and white but it still sounds pretty low.

How many pixels are you running on a single 115V circuit? I really only have 2 (I hope) 15A circuits to tap into so I am a bit concerned, especially because I rather have some more convenience with no PI but the #pixel limitation is pretty extreme.

[TomL8345]

Keep in mind you do not want to run your PS @ 100% capability, we typically design for 80%, so figure 48A for 5V PS and 23+A for 12V PS.

[munu]

Keep in mind you do not want to run your PS @ 100% capability, we typically design for 80%, so figure 48A for 5V PS and 23+A for 12V PS.

Good point. However, my calculation is based on 100% brightness and all RGB on (white). So it's an extreme example that probably would only last for a second at best. Are you saying I should even downscale from that? That means I could run only maybe 800 5V pixels on one 115V outlet and about 400 12V pixels on one 115V outlet. How do people run 10,000 pixels displays? Do they run multiple generators?

In my case I think I have two independent 115V available and I am trying to figure out how many pixels I can run from those. I prefer 12V pixels but considering the fact that they consume twice the wattage I am getting concerned.

[Stormyblade]

I've got my ehtire display plugged into one 20A 115V outlet via a power strip. A 20 panel P5 matrix (powered by 1 5V PSU), a 4 panel P5 matrix (powered by a single 5V PSU), and 3 CG-1500 boxes all containing 2 12V 350W PSUs...each of those runs on an extension cord to the power strip. All told there are about 2500 pixels (all 12V) plus the panels. Oh, before I forget, the power plugs for the Pi, FM transmitter, and 8-port switch also all plug into the power strip. I run all the pixels at 50% brightness.

[ezellner]

I run my entire display from one dedicated 20 Amp outlet. My show is limited based on this constraint. I have about 4350 WS2811 and WS2812 5 V pixels and a 32 by 128 P6 matrix display. There are 5 350 watt power supplies and one 60 watt power supply which power 3 E682 controllers, 2 E6804 controllers and a 5A-75B Colorlight card (for the matrix). I also have the RPi, FM transmitter and Ethernet switch plugged in. My show runs at 50% and it's still incredibly bright. I have no issues.

[todd1814]

I only use 2 circuits for about 14k pixels and 96 channels of incandescent lights. If you have a different circuit behind your house/in the garage, etc then run an extension cord to the front. This spreadsheet might also help your question about # of pixels per PSU. Because of the nature of sequencing, actual results vary.

[munu]

@todd1814 This is encouraging. I have outlets in the eaves and I think the ones upstairs and downstairs are independent. So I should have easy access to 2 outside circuits. I don't think I will ever get to 14k pixels because our property is pretty small. No space for a mega tree. At best outlining the house, windows, garage, a dozen mini trees, a bunch of arches, some stars, etc. Are you running 12V or 5V pixels? I am asking because according to your calculator (which gave exactly the same numbers I calculated) you can only run 483 12V pixels at full brightness on one circuit or 1000 at 5V. That is very different from 7000 pixels you run from one outlet. Also do you know how many kWh your display consumes?

[todd1814]

Current draw at 120v is different from rated current at 12v or 5v. For example, the LRS-350-12 supplies 29 amps at 12 volts using 348 watts. To calculate the amps required to supply the PSU at 120v => 348W / 120V = 2.9A. If you had a 20 amp circuit supplying 120v, you could easily run 6 of those power supplies and about 5k pixels. I have 2 30A circuits for my display, one in front of the house and one in the back. They’re both double pole breakers I installed for x-mas lights in the front and a shop out back. Each one is shared on 4 outlets.

I tried looking up my power usage earlier but the service isn’t working. I’ll post it when I get a chance but it may be hard to tell November vs December vs January.

[munu]

@todd1814 I looked at the specs for the LRS-350-12/LRS-350-5 earlier and it said 115V/6.8A. https://www.meanwell.com/productPdf.aspx?i=459 So based on that you could only run 2 PSUs at 100% on one 115V circuit. Anyways, the 14K pixels you have are the 12V or 5V? And do you have pictures/videos of your display. It sound very impressive!!!

[pmiller]

I ran 1-750 watt 62.5 amp power supply and 2 Renard SS off one circuit running 1,600 pixels at 25%.

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