Redundant Power Question

[Marcus Cook]

Hi,

I have a few Compaq ML370 and ML350 servers and i'm trying to understand the power requirements of each of the server so i can manage my UPS runtime efficiently.

The ML370 has 2+1 redundant power. I would like to now what the power draw ratio is on each power supply when the server is -

a) Running without any power problem? (50/50?)
b) When a single power supply has failed? (50-/50?)

The ML350 has 1+1 redundant power and i would also like to know the same for this.

Cheers Marcus.

[ernst limbrunner]

hi marcus

the three power supplies (ps) work in a load sharing fashion.

so if one ps fails, the load will be handled by 2 ps.

this means: you will have the same power load no matter how many ps you have.

to be correct (the electronics of the ps will add an extra 10 watt load, so after a failure you have 10 watt less load.

i added a slide (click on attachment) which shows how to make 2+1 ps redundant efficiently.

best regards from germany
ernesto