Not sure what you mean by 'server power cable' You can use any cable, including 110v. The PSUs are capable of running 110v, but only at 900w per PSU(so rather 3600w you only get 2400w of total power) You can run the rig with only 2 PSUs (if need be) you dont have to use the 3rd one. I have the same ones(But sourced by MinerDude)