Reply to post: UPS drained *real* quick.

Finally, a wafer-thin server... Only a tiny little thin one. Oh all right. Just the one...

Stoneshop

UPS drained *real* quick.

Existing DC, getting more and more crucial so it was decided to put a no-break in. 80 to 100 kVA by my estimate, going by the stuff humming inside.

A shed was built, genset and an UPS with a huge battery bank were installed and wired up. And after some dry runs the Real Test is planned: they'll just whack the Big Red Breaker on the incoming feed. Fair enough, and I don't see many options to perform that test in a meaningful but different way.

So, with a little bit of trepidation, the head of facilities and the DC manager flip that switch and yes, the UPS takes over without a hitch. Fifteen or so seconds later the diesel starts up: good, good. But then the fun starts. Note that this is 1986, and power electronics that can just twiddle 100kVA at 50Hz to sync with a diesel generator aren't quite there yet, so this setup has an UPS with a fixed output and needs the diesel to sync before the load can be switched over without fireworks and explosions.

So the diesel's controller starts tweaking the revs, but the damn thing fails to lock sync with the UPS. And of course the UPS batteries are meant to bridge maybe five minutes, during which the diesel would surely have been able to sync, but in this case didn't. And yes, the whole DC went down.

POST COMMENT House rules

Not a member of The Register? Create a new account here.

  • Enter your comment

  • Add an icon

Anonymous cowards cannot choose their icon