Motor protection circuit breaker, SIRIUS series — 12 A, CLASS 10, 5.5 kW at 400 V
The Siemens SIRIUS 3RV1011-1KA15-0BA0 is a motor protection circuit breaker designed for the main current circuit of three-phase motors. It carries a continuous rated current of 12 A and switches motor loads up to 5.5 kW at 400 V AC-3 duty — that's the power rating that governs the real motor sizing decision, not the 12 A headline alone. The overload release is thermal (CLASS 10 trip class), meaning it will trip within 10 seconds at 7.2× rated current — fast enough to protect standard induction motors during a locked-rotor event. The short-circuit trip is magnetic, with breaking capacities of 100 kA at 240 V AC and 50 kA at 400 V AC, so it handles high-fault-current panels without cascading upstream. Phase failure detection is built in, so the breaker will trip if one phase drops out — critical for preventing single-phasing damage on delta-connected motor loads. Ground fault detection is not included, so if that's required, an external ground-fault module or GFCI breaker must be added upstream.
Mounting and wiring — DIN rail, screw terminals, IP20 front
Snap-on mounting onto 35 mm standard mounting rail per DIN EN 50022, plus screw fixing for vibration-prone panels. The 45 mm width (3 module spaces) fits standard enclosure grid layouts; depth is 81 mm, height 90 mm. Screw-type terminals on both main and auxiliary/control circuits accept solid or stranded conductors: 2×(0.5…1.5 mm²) and 2×(0.75…2.5 mm²) per clamp, or AWG 18…14 for the main contacts. Stripping and torquing follow standard Siemens SIRIUS practice — no special tooling needed. IP20 protection on the front means it's finger-safe for panel-mounted use but not washdown-rated. Mounting position is any orientation, so it fits tight enclosures without derating for sideways installation.
Lifecycle and sourcing — active, quoted to order
RoHS compliance is documented with a substance prohibition date of 01/01/2013. The part carries CE marking as standard for the SIRIUS family; UL/CSA listings are typical for this series but should be verified against the specific variant's certification markings on the nameplate.