Have you looked at 415/240? You can push the savings by not having step down transformers and getting transmission voltage to 415/240 service. Then you can get 24kw (usable) tripplite PDUs for around $43.75/kw. This give you switched per outlet monitoring and you don't need a step down to 208/etc (415 -> neutral = 240v). The only issue is the ISC, you need to use in-line fuses to reduce ISC at the PDU. Still, you're only talking another $50/kw for wiring, 480 distribution panels, fuses and a custom transformer at the multi-mw level.
Planning 415 for my next build.
Hmm, I haven't heard of that service level, but maybe they're calling it something different here. For all of our mines we've been running 208v, primarily because it's MUCH easier to find 208v/1600a buildings than anything larger, and so our building cost is much cheaper. The issue we ran into the few times we've looked into bigger buildings is that usually the power hasn't been used a few years, and the allocation at the power company is gone, so they won't/can't actually deliver that anymore (no capacity left at the closest substation). We've kind of setup most of our buildouts so as much of the infrastructure as possible can move with us, as we've moved from buildings before - so generally speaking we add a couple panels 400a panels, we use 30a breakers, and those are wired directly to L6-30R. Then we have high quality extensions that we run out to the racks. On the PDU side right now we have relatively expensive ones, because we've only been using the Sonoff's for a few months, but in that time we've been sold on them. Right now our case per Sonoff is basically $30 (that's the unit, wired with C13/C14 extension, reflashed with our modded firmware), and each of our machines is about 1kw. We also run TED units on the panels themselves, so we're monitoring both at the miner, and also at the panel, so we have a really solid grasp of how power is being used. We also even go through everything with a thermal camera once a month to make sure that nothing is running abnormally hot, etc - super easy to do, and can really save your bacon.
I do know one other large miner who is running 480v, since each leg is 277v he's able to run directly off of those, as most of the server PSU's are tolerant up to that voltage. Pretty slick and he's been doing it for years without issue.
