I'm planning to use an 80A power supply (or two 40A ones) for multiple addressable LED strips. Each strip is max 90W, 20A. I want to use a single surge protected power bar for them, however they are all power bars I have seen are rated in joules.

So my question is, would an 800J power bar work without shutting off? I know 1W is equal to 1J per second, so a collective load of 3 LED strips amounting to 270W potentially would be more than sufficiently under this joule capacity of the power bar?

I'm not an electrical engineer, so hopefully this question makes sense.


  • \$\begingroup\$ No, it does not make much sense. Can you please describe what do you mean by power bar (a power strip maybe, which one, make/model/link?) and which power supply you mean, make/model/link? If you want to use a mains power strip with surge protection for power supplies, the overvoltage energy handling has nothing to do with the nominal rated current delivered to power supply. \$\endgroup\$
    – Justme
    Commented Oct 6, 2021 at 20:57
  • \$\begingroup\$ Looks like an XY problem where distribution of 80A and choice of cable and PSU is more critical than the power bar. \$\endgroup\$ Commented Oct 6, 2021 at 21:52
  • \$\begingroup\$ @Justme what I meant by power bar would be these amzn.to/3FkkLQ1 I am just looking generally but I would like to make a smart purchase that could handle the load. The power supply would be something like this amzn.to/2YmzlW0. I'm not sure what you mean by the overvoltage energy handling...do you mean that I am confusing wattage and amperage as being irrelevant to joules? \$\endgroup\$
    – lakerice
    Commented Oct 6, 2021 at 22:03
  • \$\begingroup\$ the rating in joules is for the surge not for the load. You need to estimate on your location the expected surge. There are tables for that \$\endgroup\$ Commented Oct 22, 2021 at 8:10

1 Answer 1


The Joule rating for the power strip only tells you how much energy the protective element inside can absorb in an over-voltage situation and is mostly a marketing gimmick in my opinion. Most power strips will have a hard limit at 15A/1800W since that's the limit of the NEMA 5-15P plug. Occasionally, you can find one with a 5-20P plug on the end (neutral prong turned 90 degrees) and therefore rated for 20A, but your 270W will be fine on either.

  • \$\begingroup\$ Ah I see! OK that actually cleared it up for me. I know in North America most outlets are rated for 15A, so it makes sense that most power bars would have a limit at that. \$\endgroup\$
    – lakerice
    Commented Oct 6, 2021 at 22:07

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