What it is and what it does
The Siemens 3RV1031-4HA15 is a SIRIUS motor protection circuit breaker designed for motor protection in main current circuits. It carries a continuous rated current of 50 A and is rated for 22 kW at 400 V AC, making it a fit for medium-horsepower motor loads on 400 V three-phase lines. Trip Class 10 means it will trip within 10 seconds at 7.2× the thermal setting — standard for protecting standard induction motors during start-up without nuisance tripping on normal acceleration. Breaking capacity is 100 kA at 240 V AC, 50 kA at 400 V AC, 10 kA at 500 V AC, and 4 kA at 690 V AC. At 400 V, that 50 kA SCCR handles most industrial fault levels without needing an upstream current-limiting fuse.
Mounting and integration
Mounts via screw and snap-on onto 35 mm standard mounting rail per DIN EN 50022. Any mounting position is permitted. Zero clearance required at the sides and rear — no derating for tight panel layouts. Dimensions are 55 mm wide, 140 mm high, 149 mm deep. The 55 mm width is three standard 18 mm module slots — plan panel space accordingly. IP20 protection on the front — suitable for enclosed panel installation where tools are required to access live parts.
Terminals and wiring
Main circuit uses screw-type box terminals accepting stranded conductors: 2x (0.75…25 mm²) or 1x (0.75…35 mm²). Solid conductors for the auxiliary circuit: 2x (0.5…1.5 mm²) or 2x (0.75…2.5 mm²). AWG equivalents for main contacts: 2x (18…2) or 1x (18…2). Auxiliary and control circuits use separate screw-type terminals. The breaker accepts a product extension auxiliary switch — transverse design — for remote status indication.
Environmental and operational limits
Operates from -20 to +60 °C; stores and transports from -50 to +80 °C. Shock rated at 25 g for 11 ms. Maximum operating frequency in AC-3 duty is 15 operations per hour — sized for occasional motor starts, not high-cycle jogging. Power dissipation in hot operating state is 29 W — account for this heat in enclosure thermal calculations.
Protection features and compliance
Phase failure detection is built in — trips on loss of any phase to prevent single-phasing motor damage. Ground fault detection is not included; that requires an external ground-fault module or upstream residual-current device. Rated insulation voltage 690 V, maximum AC-3 operating voltage 690 V. RoHS compliance dated to July 1, 2006 (substance prohibition date).