Do all of the breakers serve the same piece of equipment? If so the disconnect would be required because 440 requires "a disconnect".
If not, I don't know why they are requiring a disconnect for the panelboard. The section Joe cited requires a disconnect for the A/C equipment, but the breakers can serve as the required means of disconnect just as well as the disconnect switch. There is no general requirement in 440 that the disconnect be lockable.
Don
