"The only likely cause for a power filter cap blowing like that is a power surge issue or a mechanical short. The only incident like that I have experienced in decades of commercial installations was when high voltage showed up between neutral and ground on an AC outlet. "
The power surge taking out the diode bridge and allowing AC into the capacitor..
Interesting...I owned a repair shop for 20 years or so way back, when 8086 8088 processors were everywhere. There was a 3 phase transformer above the one that feed the shop. Everyone around the shop with PC, would loose power supplies, TVs up in smoke, Everything except the store. I had Topaz line conditioners in the shop..I mean top of the line at the time, FREE. got them out of a hospital closure.
They (across the street) had a thing called a Delta stinger, a Large welding / fab shop. One leg was 208-220, I think. The other two were 110, 220 between the two 110-117 . It was so they (not me) had 480 for their welding shop.They had a transformer in the facility also.
I'm kinda close on the description. That big transformer shared a common leg, up on the pole I don't recall just how. BUT at night I saw a little light show between the two. I called PGE. they ran a tape on both sides of the Topaz units. Before unit and after. 135-165 VAC spikes whenever they were welding with certain rigs, across the street. The Topaz units worked perfect. No brownouts no, Overages. PG&E paid for anyone that had complained. Something to do with that delta stinger setup, the PG&E guys said.. At my house back then, hovered at 105 then spike at night. All fixed now, but dirty AC all kinds of problems, ay..
Regards
