What this breaker does in a motor branch
The Siemens 3RV6311-1KC10 is a SIRIUS size S00 circuit breaker designed specifically for starter combinations — meaning it sits ahead of a contactor in a motor feeder, providing both overload and short-circuit protection in one 45 mm wide package. Rated 12.5 A at AC-3 duty (400 V), it handles the locked-rotor inrush of a motor up to that current class, then trips magnetically at 163 A for a hard fault. The 690 V rated insulation voltage with pollution degree 3 gives it headroom on 400 V line-to-line systems common in European and Asian panels. Mounts on 35 mm DIN rail per EN 60715, screw and snap-on, any position.
Panel fit and integration
Width 45 mm, depth 96 mm, height 97 mm. Clearance 50 mm above and below, 30 mm sides. Screw terminals accept 2x (0.75 to 2.5 mm²) solid/stranded. Torque 0.8–1.2 N·m. Operating -20 to +60 °C.
Compliance and approvals
Substance prohibition (RoHS) compliance date 05/01/2012. Shock resistance 25g / 11 ms per IEC 60068-2-27. Surge voltage resistance 6 kV. Relative humidity 10–95 % during operation. The SIRIUS series carries UL, CSA, CE, and IEC certifications standard for the brand — documentation available on request.