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Hi

I am trying to create addressable LED strip.

My plan is a 17m long strip, running along the edge of the ceiling of my room.

The led I chose is a ws2811 to which I connect an esp32 that will be operated by a 200W power supply. The whole thing works on 12V, and just need a converter for the esp32, because it works on 5V. (as far as i think - please correct me if I'm wrong!)

These WS2811 strips have a power consumption of 14,4W/m, so for 17m that would be a total of 244W. I don't think I will use it at full power anyway, so the 200W power supply is enough for me.

I don't want to burn the house down, so what would be the minimum wire size that can handle this current? And do I need to put some resistor for the data?

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  • \$\begingroup\$ 200 watts of LEDs have the light output of well over 1kW of incandescent lighting so unless you are trying to cause eye damage, I would revise this number down. \$\endgroup\$
    – vir
    Commented Jul 29 at 19:09
  • \$\begingroup\$ @vir I know, but I also wrote that I will not use the power supply at 100%, maybe only at 50%. If I used it 100%, it wouldn't do any good for the psu, and the led will be in diffuser channel \$\endgroup\$
    – Papec_12
    Commented Jul 29 at 19:19
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    \$\begingroup\$ Data sheet for WS2811 strips? You need to add your comments to your question since it has a bearing on the answer. \$\endgroup\$
    – StainlessSteelRat
    Commented Jul 29 at 19:37
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    \$\begingroup\$ You will have to manage max fault current and the allowable voltage drop. Connecting to each end of a 17m strip won't be enough since the thin traces on the strip itself won't maintain enough voltage to the middle. How often you'll need to add in supplementary connections depends on the strip, hence @StainlessSteelRat's request for a datasheet. \$\endgroup\$
    – vir
    Commented Jul 29 at 21:15
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    \$\begingroup\$ You need to give us the wire length to know the gauge. Regardless, you can check yourself here: wled-calculator.github.io \$\endgroup\$
    – user1850479
    Commented Jul 30 at 1:08

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The 12V power supply can deliver more than 16A in a fault condition if you don't fuse it, so you can check NEC ampacity charts and consider the maximum short-circuit current of the supply.

This might be a question better suited for the DIY SE, especially if this is to be a permanent installation.

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    \$\begingroup\$ The problem is that NEC ampacity charts are based on 120V and 240V wiring. At 12V the voltage drop issue is really significant. So while 14 AWG is enough for 15A @ 120V up to a couple hundred feet, with 12V you need to look at an automotive or marine chart which is based on lower voltage. And the result is much thicker wire. \$\endgroup\$
    – manassehkatz-Moving 2 Codidact
    Commented Jul 29 at 20:09
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    \$\begingroup\$ @manassehkatz-Moving2Codidact I would look at the actual current draw, which could be much less than the maximum the power supply can produce and the allowable voltage drop for the devices. It may not be thicker. Whatever wire is chosen it has to fulfill both constraints. \$\endgroup\$
    – Spehro 'speff' Pefhany
    Commented Jul 29 at 20:26

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