Motor protection circuit breaker, 1.25 A, CLASS 10
The Siemens 3RV1011-0KA20 is a SIRIUS motor protection circuit breaker rated for 1.25 A continuous current with a CLASS 10 trip characteristic. Breaking capacity reaches 100 kA at 400 V AC and holds that figure at 240 V and 500 V, then drops sharply to 2 kA at 690 V AC — so at 400 V it can interrupt a bolted fault up to 100 kA without upstream fuses, but at 690 V the fault current must be limited to 2 kA or a higher-rated device is needed upstream. Phase failure detection is built in, which protects a three-phase motor from single-phasing conditions that would otherwise cause winding overheating on the remaining phases.
DIN-rail mounting and terminal details
Mounts via screw and snap-on onto 35 mm standard mounting rail per DIN EN 50022, with any mounting position allowed — useful for tight panel layouts where vertical or horizontal orientation is dictated by cable routing. Main and auxiliary/control circuits both use spring-loaded terminals, accepting solid conductors 2x (0.25... 2.5 mm²) or finely stranded with ferrule 2x (0.25... 1.5 mm²). AWG equivalents are 2x (24... 14) for the main contacts. Finger-safe touch protection is provided on the front (IP20). The 45 mm width and 81 mm depth fit a standard SIRIUS 3RV1 footprint; backwards clearance is 0 mm, side clearance also 0 mm, so modules can be ganged without spacing.
Environmental and compliance
Substance prohibitance date of 01.01.2013 aligns with RoHS compliance; operating temperature range is -20 to +60 °C, storage and transport range -50 to +80 °C. Surge voltage resistance rated at 6 000 V, shock resistance 25g / 11 ms — suitable for industrial environments with moderate vibration and transient overvoltages.