It is rated for motor switching at 5.5 kW at 690 V AC-3 and 4.5 kW at 500 V AC-3, making it a fit for 400–690 V three-phase motor loads in control panels.
The AC-3 motor rating of 5.5 kW at 690 V is the headline — that is the maximum three-phase induction motor load this contactor can switch under normal starting conditions (inrush up to 8x FLA). For AC-4 duty (reversing, inching, plugging) the rated operational current drops to 8.5 A at 400 V, so if your application requires frequent jogging or reversing, size against the AC-4 figure, not the AC-3 kW. The AC-2 rating of 4 kW at 400 V covers slip-ring motor duty. For resistive loads (AC-1) the contactor handles up to 10 A continuous. The 24 V DC auxiliary contact rating is 10 A, adequate for most PLC or relay interposing signals.
The S0 frame is a compact 45 mm wide, 85 mm high, 91 mm deep — fits standard 35 mm DIN rail with snap-on retention. The screw terminals accept solid or stranded conductors: 2x (0.5–1.5 mm²), 2x (0.75–2.5 mm²), max 2x (0.75–4 mm²) for the control circuit, and 2x (1–2.5 mm²), 2x (2.5–6 mm²), max 2x 10 mm² for the main circuit. AWG equivalents are 2x (16–12), 2x (14–10), 1x 8 for main contacts. Pollution degree 3 (industrial environment) and IP20 at the front, IP00 at the terminals — the terminal area must be inside a panel enclosure.