Why on Earth would you think they would use PDUs? they are limiting in a high power usage environment plus the cost is horrific compared to Rack mounted Switchboards.
Maybe because it is safe? Maybe because it is more convenient? Maybe because every decent data-center uses PDUs?
Anyway, it is your farm, your gear, your power:)
My opinion is still the same, one lame and unprofessional setup. Oh, thanks for mentioning, also a cheap one. So lame, cheap and unprofessional.
I completely agree that PDUs are safe and convenient, but are costly.
And the simple fact is mining operations need to keep setup costs low.
Outfitting 40-60 racks (from the looks of the photo they roughly that many) - (Parts only)
2k For 2 PDUs
$220 for MCBs
Totals
PDUs - 80k-120k
MCBs - $8800-$13200
thats alot of spare miners.
you can get PDUs for less than $1000 - with the right APC rep you can get a 30A unmetered L6-30 strip for about $300 each.
that said, i still like the breaker-board approach. each device can have an individual breaker and you dont need as many plugs and unnecessary wire runs.