Product Identity and Key Ratings
The Siemens SIRIUS 3RV2031-4EA10-0BA0 is a motor protection circuit breaker in the S2 frame size, designed for protecting three-phase induction motors against overload and short-circuit conditions. It is a Class 10 trip device, meaning it will trip within 10 seconds at 7.2× the thermal setting current — a standard for protecting standard IEC motor starts where the rotor is not locked. The breaker is rated for motor power up to 7.5 kW at 230 V AC. Breaking capacity is a key specification for this class: the unit delivers 50 kA at 400 V AC and 240 V AC, 10 kA at 500 V AC, and 4 kA at 690 V AC. These figures are per IEC 60947-2 and confirm the breaker can safely interrupt fault currents up to those levels without upstream fusing, provided the prospective short-circuit current at the installation point does not exceed the rated value.
Mounting and Integration
Mounting is via screw fixing or snap-on onto a 35 mm standard mounting rail per DIN EN 60715. The 55 mm width (three 18 mm module spaces) and 149 mm depth fit standard panel layouts; any mounting position is permitted. Clearance requirements: 50 mm above and below, 10 mm at the sides. For audit purposes, the screw-type terminals on the main circuit accept 2× (1 to 25 mm²) or 1× (1 to 35 mm²) solid or stranded copper, requiring a Pozidriv size 2 screwdriver tip with a 5 to 6 mm shaft diameter.
Protection Features and Backup Fusing
The breaker includes phase failure detection, which is critical for preventing single-phasing damage on three-phase motor loads. It does not include ground fault detection. For installations where the prospective short-circuit current exceeds the breaker's rated breaking capacity, the datasheet specifies required backup fuses: at 400 V, a gG 125 A fuse; at 500 V, gG 100 A; at 690 V, gG 80 A. At 240 V, no backup fuse is required.