UPS failure modes (was: fire at NAC)

Timothy Brown tim at
Fri May 30 01:03:06 UTC 2003

> We are a Powerware house. We had a large number of 3kVA and 6kVA units in
> our previous data centre (no-one would stump up the cash for a large unit
> so we had to buy them as we needed them). After about 5 years (very rough
> figure), we've now had 3 or 4 units fail, sometimes in the UPS, sometimes 
> in the bypass unit. They all seem to be component failures (in the case
> of the bypass unit, a leg broke off a small capacitor). I don't think we've
> replaced any of the batteries in that time and they're still all holding charge
> well, even at full load.

Several data centers at which I have been involved in the maintenance of 
have used Powerware UPSes.  We've had great luck with them everywhere i've 
been, and this includes service and support.  The service I have received 
from them (at least in the Southeast US) has been nothing short of 
phenomenal, including calls from the reps years after they were purchased, 
even on small installations, with promises made and kept time and time 
again.  I have never been disappointed.

I'd like to echo the results of other posters:  We replaced Liebert with 
Powerware in two or three of those installations and had great luck, where 
the Liebert units would come out with spotty failures on a fairly regular 
basis (components, etc).

Personally, i'd like to hear from more people who are doing serious work 
with DC power in a collocation environment (with the market reality of 
customers who want AC).  I have seen customers request DC and nothing but.


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