[DannyBee]

The high power ones are putting DC into the car for starters.

The two extra prongs are the DC.

Conversion would generally prevent the issue you cite. They are converting three phase ac, and usually only 480v. Isolation failure would not fry the car like this because it would fault first. They are separate ac and DC cabinets with proper controls.

It may still be overvolting the DC, just not this particular way. It is much more likely the rectifier is fucked or something.

Placing 300kw (or even 150kw) of DC at like 4x the right voltage would make more than just a loud bang. It would instantly melt most insulation, for starters.

The bang is an mccb or something catching the fucked up rectifier

These cars likely got overvolt at light amperage. Otherwise lots of things would have sparked and burst into flame

[foxyv]

Sounds like you know more about these than I do. Part of why I was curious about a tear down. I'm wondering if any corners were cut on these such as improper isolation. Naturally it could also be the car itself has a short that blew itself and the dispenser up. Maybe a rubbing wire on the car with a high resistance short that melted and bridged then tripped the MCCB temporarily disabling the charger.

Judging by the quality of automobile maintenance and manufacturing I would bet on the latter now that I think of it.