Date: Fri, 5 Apr 2013 14:28:36 -0700 (PDT) From: Brian Roth <abacos_98 at yahoo.com> I did a quick look at the Eng drawings and while the power controller is 3 phase it looks like the fans are single phase. Not sure whats going on inside the power controller yet. I'll be tearing into this in a couple of weeks so if anyone has experience with the conversion, speak out. I know its been done. The power controller is REALLY simple, very much like the PDP-11 EPO controllers, just bigger. So, there is a voltage sent out on a 3-wire cable, and if you break two of the wires at the end of the chain, all units power off. The other wire powers up all units on the string. Just a little unregulated power supply and some relays. I think there's an airflow sensor in the blower plenums that breaks the EPO chain if a blower stops. Jon