Motor protection circuit breaker — what the ratings mean for your panel
The Siemens SIRIUS 3RV2011-1FA15-ZX95 is a motor protection circuit breaker designed to protect motor branch circuits against overload, short circuit, and phase failure. It is rated for a short-circuit breaking capacity of 100 kA at 240 V, 400 V, and 500 V, which means it can safely interrupt fault currents up to that level without cascading upstream — a key spec for panels that need high SCCR coordination. At 690 V the SCCR drops to 4 kA, so verify the available fault current if your line runs at that voltage. Trip Class 10 means the breaker will trip within 10 seconds at 7.2× the thermal setting, fast enough to protect standard induction motors from locked-rotor heating. Phase failure detection is built in, so a lost phase on the line side will trip the breaker — no separate phase-loss relay needed. The breaker mounts on 35 mm DIN rail per EN 60715, either snapped on or screwed, and can be installed in any orientation. Dimensions are 45 mm wide by 97 mm deep by 97 mm tall, which fits a standard 45 mm module slot on the rail. The compact footprint leaves room for adjacent contactors or auxiliaries in a motor starter lineup.
Integration into a motor starter assembly
The 3RV2011-1FA15-ZX95 is designed to be combined with a SIRIUS contactor to form a compact motor starter. The screw and snap-on mounting onto 35 mm DIN rail per DIN EN 60715 allows quick panel assembly. The breaker's main contacts use M3 screws, and the terminal accepts 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded wire. Clearance distances: 50 mm upwards and downwards, 30 mm at the sides, and 0 mm forwards and backwards — meaning it can be mounted flush against the back panel and adjacent devices.