The Siemens 3RV1021-1JA15 is a SIRIUS motor protection circuit breaker rated for 10 A continuous current with a CLASS 10 trip characteristic, meaning it trips within 10 seconds at 7.2× rated current — fast enough to protect standard induction motors during locked-rotor conditions without nuisance tripping on normal starts. It breaks up to 100 kA at 400 V AC, so it can be applied on high-fault-current panels without needing upstream current-limiting fuses in most industrial distributions. Phase failure detection is built in — if one line drops, the breaker opens, preventing single-phasing damage to the motor.
Mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 50022. The 45 mm width fits standard panel layouts; any mounting position is allowed. Screw-type terminals for main and auxiliary circuits accept solid conductors 2× (0.5–1.5 mm²) and 2× (0.75–2.5 mm²), stranded 2× (1–2.5 mm²) and 2× (2.5–6 mm²). IP20 on the front — suitable for enclosed panels where the front is operator-accessible but not exposed to washdown or dust.