For motor duty, the AC-2 rating of 4 kW at 400 V covers wound-rotor motors; the AC-4 rating of 8.5 A at 400 V covers plugging and inching duty. The 24 VDC coil draws 2.3 W both closing and holding, so the control transformer sizing is straightforward — no inrush spike beyond the steady-state power. The integrated diode means you don't need an external flyback diode across the coil, but verify polarity: the diode is reverse-biased when the coil is energized, so reversing the 24 VDC supply will short the diode.
The 45 mm width and 60 mm height fit the S00 footprint — three or four of these side-by-side (side-by-side mounting is supported) fill a standard 200 mm DIN rail segment.