UPS failure modes (was: fire at NAC)

Alex Rubenstein alex at
Thu May 29 20:29:13 UTC 2003

(header trimmed)


First off, we're all still alive here. Underlying root cause was a failure
of a capacitor in the rectifier section. We're not sure what actually
caused the failure of the failure of the capacitor, but it resulted in the
internals of the capacitor being ejected from the UPS at such a high rate
of speed, that it dented the front door of the UPS itself, and caused the
door to jump the lock and swing open.

I, personally, have never been a fan of Liebert UPS's. The electrical
engineer that we use seems to share my assessment that Lieberts, at least
Series 300's, are not built as well as the could be.

I have no direct experience with MGE, but I recall several multi-hour
outages in Jersey City Exodus, that I think had something to do with MGE
systems. I don't recall if that was human error, or not. Another negative
there, for me, is that they are French.

We own about 8 or so Matrix 5000's; out of box failure rate is hovering at
about 50%, and failure rate within first month of operation is about 75%.
However, once they pass that barrier, they tend to work. Don't overload
them, they tend to get cranky. We had one shoot flames, once, but that
wasn't assosciated with an overload.

My personal favorite: Exide/Powerware/Invensys 9315's. They just work. I
have two of them, an 80 and a 500. The 80 has been installed for nearly 4
years, and has never, ever dropped the critical load unless instructed to.
The 500 is a recent install, but seems to be doing just fine as well.

>From folks I've talked to (engineers and industry people), Powerware seems
to be known as the UPS that just works. I've yet to talk to one person who
had a powerware die on them. Myself included.

On Thu, 29 May 2003, Dan Hollis wrote:

> On Thu, 29 May 2003, Gerald wrote:
> > On Thu, 29 May 2003, Bill Woodcock wrote:
> > > I've seen two previous APCs (both Matrixes) fry batteries...  The
> > > batteries balloon up, and get really hot, and are too big to extract from
> > > the chassis.
> > I've also personally witnessed an APC do this. I'm not a fan of APC.
> > They sent us a replacement APC but I still prefer the rack mount Tripp
> > Lites we used at the last company I worked for.
> Anyone had experience with Belkin UPSes? Theyre much cheaper than APC,
> and seem to have a longer runtime. I wonder about the long term
> reliability though. Data points would be helpful.
> -Dan
> --
> [-] Omae no subete no kichi wa ore no mono da. [-]

-- Alex Rubenstein, AR97, K2AHR, alex at, latency, Al Reuben --
--    Net Access Corporation, 800-NET-ME-36,   --

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