What is all this talk about AC. Real data centers use DC. John (ISDN) Lee ________________________________________ From: Seth Mattinen [sethm@rollernet.us] Sent: Tuesday, May 26, 2009 3:39 PM To: nanog@nanog.org Subject: Why choose 120 volts? 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. ~Seth