Re: HMC Question

midrange-l-bounces@xxxxxxxxxxxx wrote on 08/18/2004 08:36:31 PM:

> 
> >We will probably just put our existing UPS's on top of the rack to 
power 
> >the xSeries and keep it simple.
> >
>     Um, UPSs on TOP of a 7 ft rack?  That sounds slightly dangerous to 
> me but it's not my computer room!!

These UPSs are rather small, although of course they are heavy.  The rack 
is so big, it doesn't seem much more dangerous than having them on a 
shelf, other than that they are higher.  We might put them on the floor 
behind the rack.

> 
>     One other thing, don't plug one UPS into another UPS. This is easy 
> to do when you have several small ones but is very bad for the UPS 
> that's getting doubled up on!  One of our customers had this setup and 
> wondered why 'that big AS/400 UPS never EVER lasts as long as all the 
> ones for the NT and other servers. What gives?'  You can guess 
> why..... 

We didn't plan on doing this, but I get the point.

> Also each UPS needs it's own circuit from the panel.  Them 
> darn things draw a BUNCHFULL more power after an outage (to charge the 
> batteries while still carrying the load)  and of course that's when 
> you'd trip the breakers when there is more than one on a circuit (and 
> coincidentally when you need it most!)

Very good point.  Worth checking into.  One of the reasons we wanted to 
somehow utilize the iSeries UPS, is that we had to run a dedicated 220 
circuit for it and that was the last circuit available in our panel.  Of 
course, we already have some other ones in the computer room we have 
already been using, but it would be nice to utilize that 220 circuit and 
UPS if possible.  How do you go about figuring out how much a single UPS 
can handle?  We are mainly interested in surviving power hiccups.

Mark



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