On Thu, Oct 24, 2013 at 3:02 PM, Chuck Anderson <c...@wpi.edu> wrote: > On Thu, Oct 24, 2013 at 09:38:43AM -0700, Michael Loftis wrote: >> I don't know anyone that assumes that the peak capability of a PSU >> (especially in network gear) is it's actual consumtion, but thats just >> me. I do agree I wish they'd publish at least approximate figures. >> It can be a deciding factor in a lot of environments today. Keep in >> mined 650W is high-line mode (~220/240VAC) - in 120V it's only going >> to be around 325W. > > This deserves clarification. The power usage in Watts for a given > hardware configuration should be the same either way--it is just that > in high-line mode 208/220/240V, you will draw less current in Amps, by > about half for twice the voltage (ohms law approximately, with a Power > Factor Correction thrown in), and because of this the power supply is > designed so that you can consume up to 650W of power only if you use > high-line mode, and if you max-out the supply in low-line 120V mode > you will only be able to consume up to 325W. This implies that if you > use low-line mode, you won't be able to install as many > modules/optics/whatever-else-uses-power before hitting the max or > losing power supply redundancy (being that both PSUs will be required > to power everything).
Yeah sorry, I was quoting the PSU wattage ratings from memory at the input voltage ranges, not usage. So yes, barring efficiency differences between 120V (low-line) and 240V (high-line) "mode" the wall usage is, of course, the same. _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp