Wire gauge concerns with multiple 600W PSUs

[xdandev91x]

Hi,
I am setting up my first show and really don't want to burn the new house down...

My main question is whether I can power inject with 18 gauge wire? If so, do I need to change my approach to power injection? The pixel voltage calculator indicated no issue with voltage drop in each power injection choice, but I didn't look into amps through each wire as I figured 18 gauge was a safe standard gauge for pixels. Do I need to power inject more often, simply to reduce amps through certain wires? Am I over thinking this?

Some notes:

• I have 200m of 18 gauge wire from a poorly thought out panic purchase and really want to avoid purchasing different AWG wire where possible.
• I understand I need a thicker gauge wire between PSU to Controller to account for 50A draw. I will account for 32A maximum on F16V4 by splitting String 1 and String 2 onto different sides of the F16V4 (so controller will never draw more than 32A on one side). I presume this is 10AWG wire (according to Google)?
• Pixels are 12V, 4 inches apart, 18AWG wire.
• All three power supplies are Meanwell 600W 12V 50A (LRS-600-12).
• Power injection points use the 3 core T-type 18AWG. I have taken into account removing the positive incoming pin when power injecting with a second power supply.
• Show is running at 50% brightness as set on the controller.
• All cable runs for power injection are less than 7m. Power injection by different PSUs is literally just based on minimum physical distance to a power supply.
• Injection points:
  • String 1: PSU 1 --> Controller --> Pwr In (PSU 2) --> 387 pixels --> Pwr Inject (PSU 2) --> 100 pixels
  • String 2: PSU 1 --> Controller --> 393 pixels --> Pwr Inject (PSU 3) --> 217 pixels
  • String 3: PSU 1 --> Controller --> Pwr In (PSU 2) --> 502 pixels --> Pwr Inject (PSU 2) --> 75 pixels
  • String 4: PSU 1 --> Controller --> 233 pixels --> Pwr Inject (PSU 1) --> 100 pixels
  • String 5: PSU 1 --> Controller --> 245 pixels --> Pwr Inject (PSU 1) --> 153 pixels
  • String 6 (Matrix left half): PSU 1 --> Controller --> Pwr In (PSU 3) --> 300 pixels --> Pwr Inject (PSU 3) --> 276 pixels --> Pwr Inject (PSU 3)
  • String 7 (Matrix right half): PSU 1 --> Controller --> Pwr In (PSU 3) --> 300 pixels --> Pwr Inject (PSU 3) --> 276 pixels --> Pwr Inject (PSU 3)

Wiring diagram below for String 1 and 5 to show different string configs. Other strings follow a similar pattern to String 5 (powered by the controller and then power injected from same PSU) or String 3 (powered by a separate PSU with incoming positive pin removed from T-type and power injected by same separate PSU).

 

[Johnnyboy]

50% is quite bright, even running my show at 30% is a little much some times. I'm using the same pixels and 600W power supplies you have.

Its not shown your drawings, but best practice is to use a Power distribution board after the PS (like this one or something similar https://aus.pixelcontroller.com/store/accessories/46-f8-distro.html). Provided the wire gauge from PS to Distro board is appropriate the 18awg/0.75mm2 is fine for what you have proposed. The premade power injection cables use exactly the same gauge as what you are using (I use a bunch of these 2core premade cables for power injection https://www.lightitupleds-xmas.com.au/product/ext-25ft-2pin-xc/162?cp=true&sa=true&sbp=false&q=false)

For my setup I am power injecting/balancing every 300 or so pixels, meaning that power is never more than 150pixels away. No issues with the show and most of my outputs have between 500-650 each. That number of pixels/port is not best practice, but I only wanted to use the one controller.

hope that helps

 

[xdandev91x]

I am planning for 50% but will most likely turn it down. Given I don't have that many pixels, I figured 50% brightness and working my way down might be a good plan.

I completely overlooked the power distribution boards! This would have made things sooooo much easier. Placing an order for next year for sure!

So I assume that I should be fine with the 18 gauge wires? The pixel calculator had no wire amp above 6A, but googling the 18 gauge wires, they are rated to 2.6A only - and the screenshot I included in the post has the amp load listed as 5.25A and 5.875A - and that is with power injection at a higher frequency than 300 pixels too.

I suppose I am over-thinking this?

 

[Indigogyre]

Just an FYI, most pixels watts are no longer 0.6 and are closer to 0.3 these days. If possible it's better to take an exact measurement but you could safely go down to 0.4 per pixel and still have room.

 

[xdandev91x]

Just an FYI, most pixels watts are no longer 0.6 and are closer to 0.3 these days. If possible it's better to take an exact measurement but you could safely go down to 0.4 per pixel and still have room.

Fair enough! I'll take a measurement tomorrow at full brightness and see how lucky I fair, given the pixels are brand new also.

 

[someoneAUS]

• String 2: PSU 1 --> Controller --> 393 pixels --> Pwr Inject (PSU 3) --> 217 pixels

This one might cause some issues. Power injecting from PSU 3 means you will be breaking the positive I assume at that point? If so it wont be trying to pull power for ~200 pix from the PSU one at the front and and ~200pix from PSU3 at the back back rather all 393 will be coming from the PSU1 which IMHO is potentially pushing it.