The Siemens SIRIUS 3RV1011-1FA10-ZI45 is a motor protection circuit breaker in size S00, rated for 5 A operating current with an adjustable overload release covering 3.5 to 5 A. The CLASS 10 trip class means it will trip within 10 seconds at 7.2× the current setting — fast enough to protect standard induction motors during a locked-rotor start without nuisance tripping on normal acceleration. The magnetic short-circuit release is fixed at 65 A (the N release), so it clears hard faults upstream of the motor starter. Mounting is screw-and-snap-on onto 35 mm DIN rail per DIN EN 60715, and the breaker accepts any mounting position. The screw-type terminals for the main current circuit are arranged top and bottom, which keeps the wiring layout clean in a panel. Clearance distances are 20 mm upwards and downwards, 9 mm to the side, and 0 mm forwards and backwards — meaning you can butt it against the back panel or adjacent devices without extra spacing on those faces.
Integration note
Size S00 is the smallest frame in the SIRIUS 3RV1 family — 45 mm wide, 75 mm deep, 90 mm high. It snaps onto the same 35 mm DIN rail as contactors and overload relays, and Siemens publishes a combination table for direct mounting with S00 contactors (e.g., 3RT2 series) without additional wiring between the breaker and contactor. The power loss at rated current is 7.25 W total (2.4 W per pole), so no special ventilation is needed in a standard IP20 enclosure.
Rated switching capacity at 400 V AC is 1 500 W (the breaking capacity in watts for motor loads). The breaker is designed for motor protection per IEC 60947-2 and -4, with thermal overload and magnetic short-circuit release built in — no separate overload relay needed for the motor branch.