The 6000-watt (W) power supply for the Cisco Catalyst 6500 Series chassis is a dual AC input power supply. When both inputs are at high line (220 VAC nominal voltage) then the output is 6000W. When both inputs are active but at least one is operating at low line (110 VAC nominal voltage), or a single input is active and running from a high line (220 VAC nominal voltage) source, the unit is capable of providing 2900W output power.