On 27/01/2021 23.27, Lew Wolfgang wrote:
On 1/27/21 1:42 PM, Carlos E. R. wrote:
My experience with UPS may be limited, but back in the day I ran a 10-KVA UPS to power a group of Sun Microsystem servers. It was a nice UPS with a ferroresonant transformer that conditioned power as well as running the 10-KVA load for 30-minutes. In my experience, we experienced more unplanned power outages caused by the UPS itself than if we directly connected to the mains. After we retired the Suns and switched to SuSE I once managed to keep the main server up and running continuously for a bit more than 4-years, without the UPS. Without a reboot! It was a busy server too, with a hardware RAID controller. Do you remember how did the UPS fail? I'm curious.
The UPS never actually failed, except for a time or two when the battery bank needed to be replaced. The unscheduled outages were more due to me fiddling around with it and messing it up.
:-D When I was installing air conditioning on my "computer room", the technician connected his power drill to the UPS output socket, then looked bewildered when his drill would start for a second then die as soon as he touched the brick wall to work :-D Of course, my computer crashed instantly. He did not think of asking "where should I connect my tools?"
It was a Best Ferrups 10-kva model. Looks like they're still made:
https://www.eaton.com/us/en-us/catalog/backup-power-ups-surge-it-power-distr...
The battery bank was in a separate container as big as the main unit. They were free-standing, not rack mounted. It would power the load through the saturated transformer and when power dropped it would use the battery dc (switched I guess) to serve as the AC input to the primary. The load would never see a glitch, until the battery bank discharged. The saturated core of the transformer served to regulate and smooth power to the load.
Nice. -- Cheers / Saludos, Carlos E. R. (from 15.2 x86_64 at Telcontar)