Troubleshoot P12

[Kaden]

Note: my comments are from a newbie, so I have no real world experience yet!

 

[David_AVD]

1260 pixels x 0.06A (per pixel) = 75.6 Amps !!!

Way more than the PSU and that cabling can handle I'd say.

I am sure your .06a is actually more like .03a, but that is still 37.8a!

I was working on the figures of 20mA per colour per pixel (3 x 0.02A = 0.06A).

The DC cable in the picture seems to be 1 sq mm, which is good for about 10 Amps. Even 37.8A would require conductors 4 sq mm in size. A general rule of thumb is 10 Amps capacity per sq mm of cable size, but this needs to be derated for longer cable lengths.

If you never drive all pixels to full white, then the average power consumption will be reduced, but since PWM is the dimming method, each pixel still draws current spikes of the full rated current. Of course these spikes are distributed (in time) somewhat, but how much so is something you have no influence over.

So, what I'm saying is that you really need to size the power cables to suit the worst case load (all pixels white). If you use thinner cabling, when weird stuff happens how can you be sure the issues are not power related?

 

[Kaden]

The other thing that comes to mind is centralised power at 5v and pushing the cable to its max - voltage drop increases with length of cable AND further increases when the cable approaches max load (amps).

You really need to be checking the voltage drop at the pixels at full load (all white)

 

[David_AVD]

I have my PSU close (right next to) to the PIXAD8 and used 2.5 sq mm cable for the DC power input. I'm only running about 6A worth of WS2811 strip off each PIXAD8 though. The cable from the PIXAD8 to the pixels was about 1 sq mm as they were about 10m from the controller.

 

[Kaden]

Also anyone reading my posts in this thread, ignore my late night maths!

 

[toodle_pipsky]

I think we might have a go-er here. Again, it's hard to tell in broad daylight, but it does look promising. Will check tonight.

Thanks you all very much for your help. I really appreciate it.

 

[toodle_pipsky]

Honest to God I think I'm cursed. Here's a prime example why you should test before set up . . . . . ugh.

My issue isn't 100% fixed. Is it still a power imballance issue? I have 945 and a full P12R on 1 power supply, 875 and 4 universes on another and 420 running off a third. The wired random flashing has started up again, but the sequence hasn't stalled like before. Or a thought occurs to me - have I tied in the 3rd supply properly? How should 3 supplied be tied in? Does each supply common need to connect to each other's?

 

[Kaden]

You might be mixing terms here, common is a term used in AC power.

If you meant the DC term ground/negative then every power supply that supplies power to the pixels on a particular controller needs to be grounded to that controller regardless of voltage.

 

[Slite]

Sounds to me that power is one subject that needs to be elaborated on in the ACL Manual.

If your not trained as or used to working with electricity, this can be kind of hard to understand without in depth explanations.

 

[toodle_pipsky]

Thanks for all the help guys. This arvo I unhooked everything and started hooking up from scratch from 3 power supplies making sure I had 1 supply per half of the controller - this sorted the problem. All that flakey stuff was due to me misscalculating my power needs and trying to mix and match supplies. (I do still have 4 random strings out and 1 that appears back to front, but they are all my wiring errors).
Moral of the story, be really clear and well researched in your power needs. Thanks again.

 

[toodle_pipsky]

Hey guys, have had everything working fine for the 1st week of everything running. This week the gremlins have got in!

The tree "freezes" at the start of the sequence. It's only a 30 second long sequence with a rainbow chase, sparkle, then another rainbow chase. The majority of the tree is run from 1 P12R - 16 universes, first 12 are the ones that stop working. I checked out the board and network switch while the sequence was running and that 1 board is the only one without lights flashing on the switch and the board's network connection. I did have it set up as Unicast to it's specific address, and tried changing it to Multicast, that hasn't worked. Could it be a dodgy cable that's just finally given up?

 

[toodle_pipsky]

Well I finished early today so I thought I'd give troubleshooting a bash.

Swapped over cables, no joy. Tried reflashing firmware, no joy. I connected to it through IE/Chrome and could successfully get the test pattern running. Now that the test pattern is going I can't get back in to turn it off. Seems like once the lights are going I can't get back into the Config/Diagnostic console.

So . . . . could it be a hardware issue? Either with lights or board? Is there still something else to try?

 

[fasteddy]

Try disabling your antivirus. I know with AVG antivirus i cant connect to the web interface on the p12r while AVG is active

 

[toodle_pipsky]

Thanks for that. I did disable MS Security and it let me in, don't know how much of that was co-inky-dink! Was able to turn test off so thanks! However still freezing. The board becomes unresponsive once the sequence is sent. Can't ping it or reconnet the web interface.

I thought well maybe I'll run the test pattern so it changes and it's doing something! When I run the 2 P12R in test they really don't like it - both are strobe badly. So back to 3/4 non working tree.

 

[fasteddy]

Seems like you have some major ground loop issues occuring, can you do a detailed layout of how things are connected. The issue may have also come about from your wiring changes or there could be a dodgy power supply generating interferance. So it will be a procees of illimination so disconnect things and see when the interferance stops then from there try to isolate the cause.