I have a pure curiosity question for the NANOG crowd here. If you run your facility/datacenter/cage/rack on 120 volts, why?
I've been running my facility at 208 for years because I can get away with lower amperage circuits. I'm curious about the reasons for using high-amp 120 volt circuits to drive racks of equipment instead of low-amp 208 or 240 volt circuits.
208 isn't all that great. On one hand, a 20A 208V circuit is vaguely more convenient than a 30A 120V circuit because it is delivering a bit more power to the rack (3328 vs 2880), and it's likely to work with a lot of modern equipment containing autoranging power supplies. On the flip side, with 120, you don't have to have "odd cords," and it is somewhat easier to "right-size" power for a rack (20A, 30A, 2x20A), so for an average rack that isn't crammed with high power webhosting 1U's (etc), a customer might actually find that the ability to right- size the power feed is more flexible with 120V. And I don't like not having anywhere to plug in my power screwdriver's recharger... I suppose I should see if I can find someplace that has a transformer of an appropriate size, or does anyone already have the part number for something that can provide a few hunderd milliamps of 120V from 208? :-) ... JG -- Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net "We call it the 'one bite at the apple' rule. Give me one chance [and] then I won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN) With 24 million small businesses in the US alone, that's way too many apples.