[Gllug] Was there Power Outage at Telehouse?

[Ryland, Peter]

On Thu, 2006-08-17 at 23:54 +0100, Mike Brodbelt wrote:
> Each PDU outputs 3 phase, and you can have feeds from the same phase on
> two different PDUs. Most data centres also allow feeds from different
> phases of the same PDU. I'm not quite sure how they arrange to make sure
> you never get ~450 volts across your kit, but it can be done.

Sorry, minor nitpick: you multiply by sqrt(3) to get the voltage across
two phases, so you get:

Nominal  Nominal
single   3-phase
phase:   voltage:
220V     380V
230V     400V
240V     415V

This is because they are out of phase by 120 degrees, and they add like
vectors.

Pete


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