22 A AC-3 at 400 V — the motor-starting rating that decides fit
The 3RA2120-4CE27-0BB4: That 22 A figure is the motor full-load current it can switch under IEC AC-3 duty — the standard for squirrel-cage motors during starting and plugging. For a 400 V three-phase motor, this covers loads up to roughly 11 kW (15 hp), though the exact horsepower depends on the service factor and local code. The S0 frame size keeps the footprint compact: 45 mm wide, 243 mm tall, 107 mm deep.
Spring terminals and pre-assembled contactor — fewer line items on the BOM
The main circuit uses spring-loaded terminals — no screw torque to verify, no loose strands. The supplied contactor is a 3RT2027-2BB40, and the link module is 3RA2921-2AA00, so this is a factory-assembled starter that ships as one order code. That collapses three BOM line items into one, which simplifies procurement and reduces the cost per PO for tail-spend categories. The clearance requirements are: 50 mm above, 20 mm in front, 10 mm below, 20 mm at the sides. That 0 mm rear clearance means it can sit flush against the back panel — useful when gland-plate depth is tight.