What it is and what it does
The Siemens 3RV2131-4XA10 is a SIRIUS motor-protective circuit breaker with integrated overload relay function — a single device that combines short-circuit protection and thermal overload protection for three-phase motors. Trip Class 10 means it will trip within 10 seconds at 7.2× the thermal setting, matching the startup profile of standard squirrel-cage induction motors (pumps, fans, compressors) without nuisance tripping on inrush. Rated breaking capacity reaches 30 kA at 400 V AC, 100 kA at 240 V, and 4 kA at 500 V — sufficient for most industrial panel fault levels. The continuous current rating at 480 V is 59 A, and at 600 V also 59 A, so it covers a 30–60 A motor range in 400/480 V systems. Phase failure detection is built in, which protects motors from single-phasing — a common failure mode in line-side fuse scenarios. Ground fault detection is not included, so if ground-fault protection is required, pair it with a separate GFCI module or upstream residual-current device.
Mounting and integration
Mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 60715. Any mounting position is allowed, which simplifies panel layout. Clearance requirements: 50 mm above and below, 10 mm to the side, 0 mm forward and backward. That 50 mm vertical gap is the one to watch — stacking multiple units without it can derate the thermal performance. Main-circuit terminals accept 2× (1–35 mm²) or 1× (1–50 mm²) solid or stranded copper. Screw-type terminals with M6 thread for the main contacts. Strip length and torque values follow standard Siemens SIRIUS practice — use a torque screwdriver, not an impact driver, to avoid terminal damage. Dimensions: 75 mm wide, 140 mm high, 149 mm deep. The 149 mm depth includes terminals.