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this is kind of a noob question:

I have a power strip (extension cord from my wall AC outlet) that is rated for 250V 10A. Over this power strip i'm connecting a power supply that gives an output of 12V 20A.

What's the relation between the power strip current rating and the PSU one?. I mean, how could you state the needed value for the power strip based the PSU current rating?

It's enough to just calculate the power consumption in Watts on the PSU (Vout * Output current) being lower than the one rated for the power strip?

(I'm not connecting anything else besides the PSU on it).

Greetings.

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  • \$\begingroup\$ Appliance AC current ratings are for breaker rating at max load and not what is actually flowing when lightly used. \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Oct 1 '17 at 22:56
  • \$\begingroup\$ You need to look at the PSU's input current rating since the input of the PSU is what is connected to the power strip. \$\endgroup\$ – user253751 Oct 2 '17 at 0:19
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It's enough to just calculate the power consumption in Watts on the PSU (Vout * Output current) being lower than the one rated for the power strip?

Yes. Power requirement of the PSU is \$ P = VI = 12 \cdot 20 \ = 240 \ \mathrm {W} \$.

On 230 V mains the current required by the PSU is \$ I = \frac {P}{V} = \frac {240}{230} = 1 \ \mathrm {A} \$ (plus a little).

Your power strip is fine.

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    \$\begingroup\$ Cool, that I = P / V was the missing part in my thought.. With one side being AC and the other DC i tend to separate both parts as different things.. Thanks! \$\endgroup\$ – rccursach Oct 1 '17 at 22:26
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    \$\begingroup\$ The quick way to think of it is that if you drop the voltage by a factor of 20 then the current goes up by a factor of 20. (Don't forget to factor in a bit for power supply losses.) \$\endgroup\$ – Transistor Oct 1 '17 at 22:31

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