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Help identifying a video panel


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Daisy chaining 30 panels is unlikely to be ideal. As other experienced commenters have pointed out, you're almost certainly over 30mA of leakage current (you do have RCDs on this setup??), and you're likely over current for the power connectors (though as they're likely copies not made to any standard who knows what the limit is meant to be).

I'd be looking for at least 2 power drops on 30 panels, but if working on a 3 phase supply I'd probably do 3 to keep it spread across phases. Drop a 32/3 (or 16/3) supply to each LED wall, then split each screen into 3 segments.

Inrush current can be significant on LED walls as the capacitors in the SMPSUs charge up. The better units manage this with inrush limiting components, cheap ones your guess is as good as mine. Running on a generator you'll probably get voltage or frequency droop as they power up, but if you're only running kit with SMPSUs I suspect most of it won't care too much as long as the AVR doesn't overshoot as it recovers. On a stiffer supply you may pop breakers, but I'd usually overspec the supply to LED walls to accommodate inrush and the earth leakage of that many SMPSUs (hence that 32/3 to each wall).

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For what it's worth I've just tested a domestic 32" TV which hasn't been on for several days.

Placing a 1 ohm resistor in the neutral lead and measuring with an oscilloscope on 25V/cm I saw a spike of a tad under 100V (100A). Can't quote duration due a 100mS/cm in order to catch switch on.

Stabilised at ~350mV (350mA) and 0.33/0.34A on clamp meter 400A range, TV rated at 90W.

Earth lead current 1.85mA on 20mA~ range of multimeter.

I don't know how effective the resistor test really is, or if the results are typical, but using these figures your 0.75A could be knocking 250A inrush. 10 of my TVs will be tripping RCD.


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Before I knew about the use case this chap had ordered a 32A-3P to 32A single phase outlets with MCB protection - with no RCD or RCBO in the distro.

He has 3x 32A plug to PowerCon sockets jumpers and is using these to power his 76 screen off the generator.

He has them divided into Left, Right & Rear arrays and from what he was telling me, he was using a phase for each.

I am remote from the chap and haven't seen the actual connection of the 76 screens.

He is not technical and I've been explaining about balancing phases to not put undue stress on the gen and neutral line.

He want's to buy more distros and I'm thinking a better way forward would be to 2x (or poss more) PowerCon outlets per phase. 
In that way it would be much easier for him to split the screens into more managable groups of e.g. 5 or 6.

Any thoughts?


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3 hours ago, Stuart91 said:

Apart from anything else this arrangement will make it much more straightforward to narrow down faults. 

whatever the multiple meeds to be 3, IE 3,6,9,12 groups to keep it balanced.

I don't have an issue with a phase per array if it's balanced but I imagine the rear screen is a different size/format to the others.

Second thoughts, I'll make an assumption that sometimes not all the arrays will be used and therefore each should run 3ph.

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On 1/15/2023 at 4:27 PM, DanSteely said:

He is not technical and I've been explaining about balancing phases to not put undue stress on the gen and neutral line.
Any thoughts?

It's not possible for anyone to simultaneously be:

  • non-technical
  • responsible for this system
  • compliant with section 6.1 of BS7909:2011

(Short answer; I'd concur with the suggestion of 5-6 screens per circuit. Electrically compliant panels would generally be good for 16 or 20A, even if these aren't compliant, for the sake of standardisation I'd suggest 16A single phase circuits each with 30mA RCBOs, and either a 16A Cee or a True1. If screens are 32/32/12 panels then particular emphasis needs to be put on balancing across phases rather than having a screen per phase. But I'm sure you knew that)

Edited by Yorkie
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