Comment by kalleboo

I think the vacuum story gets retold because it's so close to real-life stories.

The UPS on a server I manage would trip once a week around the same time. The old story came to mind and sure enough, once a week it was time to vacuum and someone would plug in a vacuum cleaner into the same circuit (700W vacuum cleaner on a 100V/15A circuit), causing enough voltage dip to kick the UPS into gear.