Methods, systems, and computer programs encoded on computer storage medium, for determining that an update of the PSU firmware is received for a plurality of PSUs of a data center; determining that an update priority flag indicates unthrottled operation of the data center, and in response: determining that a number of PSUs of the data center is greater than a minimum number of PSUs for the unthrottled operation of the data center, and in response, applying the update to each of the PSUs; determining that the number of PSUs of the data center is less than the minimum number of PSUs for the unthrottled operation of the data center, and in response: adjusting a power capacity and maximum current state of the data center, and after adjusting the power capacity and the maximum current state of the data center, applying the update to each of the PSUs.