A min of 2500 W would be needed for the sup 720. (depends also on other modules installed).
A fan tray upgrade (WS-C6K-9SLOT-FAN2) can be done to provide additional cooling for equipments.
the supervisor has to be installed in slots 5/6.
Sankar Nair
UC Solutions Architect
Pacific Northwest | CDW
CCIE Collaboration #17135 Emeritus