The incident in question was a test of the backup systems under load. I don't recall exactly what happened (its actually more common than you might think) but either a) the test failed or b) (and more likely) the test was a success but due to forgetfullness, they never swithced back to the primaries or they attempted to do so but didn't notice that it didn't work. If your systems are designed to operate with main power being down for 6 hours (the minimum in my oppinion), you should have no trouble running on this in the instances of stage 3 etc. Of course, as has been pointed out earlier, environmental regs and general cost per kw of backup vs primary can make this moot.. On Tue, Jan 16, 2001 at 10:28:38AM -0800, Jerry Scharf wrote:
I was waiting for Sean to respond to this first, but it often is unwise to use a backup system as a main.
I remember a lower manhattan telco facility (can't remember the address) that switched to backup, didn't handle the procedures correctly and ran the batteries down to zero. Took all sorts of things off line, including all air traffic control for JFK/LAG/EWR for 10+ hours. This for a facility that is in general prepared to run on backup and does it on a regular basis.
Unless you have a group that is really really set up to run on local power as your main source, it's best to use it as the backup it was designed to be. Unless the facility is ready to make a major commitment to local power generation, the risks outweigh the benefits, IMO.
jerry