The Siemens 3RV2131-4EA10 is a SIRIUS motor-protective circuit breaker with integrated overload relay function — one device handles short-circuit and overload protection for a motor branch. The Trip Class 10 means it trips within 10 seconds at 7.2× the thermal setting, which matches the heating curve of standard three-phase induction motors. The 30 kA breaking capacity at 400 V AC means it can safely clear a bolted fault on a 400 V distribution board without upstream fuses needing to act first — that's enough for most industrial panel secondary feeders.
Where it lives in the panel
The 75 mm width and 149 mm depth fit a standard 8-module wide panel footprint; allow 50 mm clearance above and below for wiring and heat dissipation. Terminal capacity accepts up to 35 mm² stranded on the main contacts, so it handles the incoming feed from a busbar or line-side contactor without pigtails.