Dual power supply draw?

Ben Scott mailvortex at gmail.com
Sun Mar 22 21:49:04 CDT 2009


On Sun, Mar 22, 2009 at 10:11 PM, Brian Mathis <brian.mathis at gmail.com> wrote:
> If a server has dual power supplies, and each is connected to a
> different power feed, do the PSUs pull from both at the same time ...

  Yes.  The power draw is balanced between all functional supplies.
If a supply or source fails, the remaining functioning units take over
the load.  It's active/active, not active/standby.

> Also, do you see any other problems with have each power supply on a
> separate circuit?

  I've got a PE 2900 with two supplies, each on a different UPS, each
on a different branch circuit, no problems yet.  Knock on wood.

  It's possible to run into weirdness with ground potential
differences if you've got equipment connected to sources that don't
share the same earth ground, but that's rather an edge case, and
unlikely to apply to a single server.

-- Ben



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