Motor Protection Circuit Breaker for Panel Integration
The Siemens SIRIUS 3RV1031-4FB10-0BA0 is a motor protection circuit breaker rated for 40 A continuous current with a CLASS 20 trip characteristic, sized for 18.5 kW motor loads at 400 V AC. It snaps onto a 35 mm DIN rail per DIN EN 50022 and accepts screw-type box terminals for the main circuit — 2x (0.75 … 16 mm²) solid or 2x (0.75 … 25 mm²) stranded, with a single run up to 35 mm² stranded. The 55 mm wide, 140 mm tall, 149 mm deep footprint leaves zero clearance needed at the sides or rear, so panel fill factor is straightforward. Phase failure detection is built in; ground fault detection is not. For auxiliary switching, the design accepts an add-on auxiliary switch block (screw-type terminals on the control circuit side). The front face carries IP20 protection, adequate for enclosed panel mounting where no washdown or dust ingress is expected.
Breaking Capacity and Coordination
Rated ultimate short-circuit breaking capacity varies by voltage: 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. This covers most industrial low-voltage distribution scenarios up to 690 V. The surge voltage resistance is rated at 6 kV, and the breaker withstands 25g shock for 11 ms — relevant for installation on vibrating machinery or conveyors. Maximum operating frequency at AC-3 duty is 15 operations per hour. Power dissipation in hot operating state is 29 W total (9.7 W per pole), which should be factored into enclosure thermal calculations when grouping multiple breakers.
Mounting and Environmental Range
Mounting position is any orientation. Operating temperature range is -50 to +60 °C; storage and transport range extends to -50 to +80 °C. The breaker mounts via screw and snap-on onto standard 35 mm DIN rail. Screw-type terminals accept AWG 18 to 2 for the main contacts (2x or 1x conductor).