...Up at the Skunk Works North Campus. I'd gone up to investigate a smaller problem, and had, and it looked possibly solved. I was sitting at the desk when...the fluorescent lights went dim (!) and the entire building growled -- but not for long.
The lights went out, the air-handlers stopped and it was dead dark and silent. Distantly, I heard a loud cough, a deep rumble and a rising whine: the MegaWatt genset starting up!
Thirty seconds later, the lights were back on and I was scrambling around resetting things, hoping the air-handlers would start up soon. The place ran on the generator for about an hour and a half before switching back to commercial power a lot more nicely than it had gone away.
There'd been an accident a couple of miles away, taking out a power pole and dropping two of the three phases, which is never good.
Also not good? About ten minutes after the store-bought juice returned, the lights flickered and something went BANG!-pffffft not very far away. It sounded like a shotgun and was followed by a whiff of smoke! I called the Fire Department and they were on the scene in minutes; but we went through the building three times without finding anything. They could smell the smoke when they arrived but it dissipated. So they left; meantime, my boss and I had spoken and he asked me to wait until he showed up, and we did the same walk-through. Nothing.
Present theories are A) an overstressed light ballast failed safe or B) we have incinerated a mouse in the 480V/1200A switchgear.
Darned if I know. It was more excitement than I wanted.
5 months ago