Can a DC motor be of specification 320Watts, 3A, 24 V?
In my opinion this is the nominal specifications. And the power is written as peak :) This is like on cheap stereo written for example 3000W, but the RMS is always hidden and much lower:))

Anyway, i think this specification of power shows peak power or stall current.

UPDATE

If you want to use it for wheelchair this is not the motor you need. Because it is C.C.W - counter cock wise, that means this motor isn't recommended for clockwise turning. It is limited due to angled brushes. H-class is insulation class. H stand for 180C.