Motor protection circuit breaker, size S00
The Siemens SIRIUS 3RV1011-0KA10-ZI45 is a motor protection circuit breaker in the S00 frame size, designed to protect induction motors against overload, short circuit, and phase failure. Its CLASS 10 trip characteristic means it will trip within 10 seconds at 7.2× the current setting — fast enough to protect a motor winding during a locked-rotor event without nuisance tripping on normal starting inrush. The adjustable overload release covers a setting range of 0.9 to 1.25 A, so you dial in the motor's full-load current rather than swapping the breaker for a different rating. Mounting is screw and snap-on onto 35 mm DIN rail per DIN EN 60715, and the mounting position is any — no derating needed for horizontal or vertical orientation. The screw-type terminals on top and bottom accept solid or stranded conductors up to 2.5 mm², with a tightening torque of 0.8 to 1.2 N·m. For a panel-builder, this means the breaker fits into the same DIN-rail footprint as a contactor of the same S00 frame, allowing a direct bus-bar link without extra adaptors.
Integration with S00 contactors
The S00 frame size is the smallest in the SIRIUS motor-protection range, designed to pair directly with S00 contactors for a compact motor starter assembly. The breaker's 45 mm width matches the contactor width, so the two snap side-by-side on the same DIN rail with a common bus-bar kit. Power dissipation at rated current is 5.5 W total (1.8 W per pole in hot state), which is low enough that no forced cooling is needed in a standard IP20 enclosure.