Its 24 VDC coil is the standard pickup for PLC-driven outputs or relay interposing — no AC hum, no rectifier needed. The AC-3 motor-switching capability at 400 V is the headline number: 15.5 A, which translates to roughly 7.5 kW on a standard 400 V three-phase induction motor. That is the load you size the contactor for, not the AC-1 resistive current. For Type 1 coordination (no fault withstand after a short) the upstream fuse can be as high as 63 A gL/gG; for Type 2 coordination (contactor still usable after a fault) drop to 25 A. The difference matters for panel selectivity — if the line side is a motor circuit breaker, Type 2 is typical.
Side-by-side mounting is allowed with zero spacing (: 6 mm side clearance is the minimum, but the evidence says side-by-side is permitted, meaning the 6 mm is the free-air gap, not a mandatory spacing if the panel is ventilated). Wire the main circuit with screw terminals accepting 2x (1 to 2.5 mm²) stranded or 2x (2.5 to 6 mm²) solid, max 2x 10 mm². Control wiring uses the smaller terminal set: 2x (0.5 to 1.5 mm²) solid or 2x (0.75 to 2.5 mm²) stranded, max 2x 4 mm².