Motor protection circuit breaker, SIRIUS series
The Siemens 3RV2031-4KA15 is a SIRIUS motor protection circuit breaker designed for motor protection, with screw-type terminals for the main current circuit. It mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 60715, in any mounting position, making it a direct fit for standard industrial control panels. Rated operating voltage spans 20 to 690 V. At 230 V it handles 22 kW motor loads; the breaking capacity at 400 V is 30 kA, and at 690 V it still interrupts 2 kA. Trip Class 10 means it clears a locked-rotor condition within 10 seconds at 7.2× rated current — standard for general-purpose induction motor starting. Phase failure detection is built in; ground fault detection is not. The auxiliary contact ratings are 1 A at 24 V, 0.15 A at 60 V, and 0.5 A at 230 V — enough for a PLC input or contactor coil feedback.
Dimensions and panel fit
The 3RV2031-4KA15 measures 55 mm wide, 140 mm high, and 149 mm deep. Clearance requirements: 50 mm above and below, 10 mm at the side. The 55 mm width matches the standard SIRIUS 3RV2 frame footprint — it occupies one 55 mm slot on a DIN rail, same as the 3RV2021 siblings.
Environmental and mounting specs
Operating temperature range is -20 to +60 °C; storage and transport range is -50 to +80 °C. The screw-type terminals accept 2× (0.5 to 1.5 mm²) or 2× (0.75 to 2.5 mm²) solid or stranded conductors. Main contact terminal size is M6.