Motor protection circuit breaker, 10 A, CLASS 10, 100 kA
The Siemens SIRIUS 3RV1021-1JA10-ZW96 is a motor protection circuit breaker rated for 10 A continuous current with a CLASS 10 trip characteristic, meaning it will trip 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. Breaking capacity reaches 100 kA at 400 V AC, which lets this breaker sit upstream of a motor starter without requiring a separate backup fuse in most industrial panels — the SCCR of the combination is effectively set by this breaker's rating. Phase failure detection is built in, so a lost phase on the line side will trip the breaker before single-phasing damages the motor winding. This is a standard feature on SIRIUS motor-protection breakers and saves adding a separate phase-monitor relay.
Mounting and integration
Mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 50022. At 45 mm wide, it occupies a single modular unit — useful when packing multiple motor branches into a compact panel. Main circuit terminals are screw-type, accepting 2x (1 … 2.5 mm²) solid or stranded, or 2x (2.5 … 6 mm²) — covers common motor-feeder wire sizes up to 6 mm². No auxiliary contacts are pre-installed (0 supplied), but the breaker accepts add-on auxiliary switch blocks if remote status signaling is needed. IP20 on the front means finger-safe from the panel face, but the terminals are not protected — standard for a DIN-rail component inside a closed enclosure.