The heat dissipation value of the Altivar 61 Drives when in Ready State (RDY - Drive is powered up but motor is not running) depends on the size of the Drive and of the hardware configuration that is the option cards used (like encoder card, IO extension card, controller inside card etc).
Considering 2 option cards (2 * 3.25W) and 1 encoder card (4.25W) the heat dissipation is approximately between 34W and 53 W up to 18.5KW Altivar 61 Drives.
Maximum is 100W for the biggest size of Altivar 61 Drive.