According to the poster, it should be a 500 kilowatt generator with a capacity of 625 kva, or approximately 630 kva.
Generally speaking, the rated power of a diesel generator is the power of the generator set. For example, for a 500 kW generator, the rated power is 500 kilowatts and the capacity is 625 kva. Regarding the power of this unit from the poster, you need to confirm the power of the diesel engine and generator. Some manufacturers will under-match the horsepower.