The Siemens 3RV2021-1JA20 is a SIRIUS motor protection circuit breaker designed for motor protection. It carries a Class 10 trip characteristic, meaning it will trip within 10 seconds at 7.2× the thermal setting — the standard for protecting standard induction motors during start-up without nuisance tripping on normal acceleration. Rated breaking capacity hits 100 kA at 400 V AC, so it can safely interrupt high fault currents on industrial distribution without cascading upstream. Phase failure detection is built in — a critical feature for three-phase motor protection that prevents single-phasing damage. Mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 60715. The 45 mm width fits standard panel layout grids; depth is 97 mm. Spring-loaded terminals on the main circuit accept 2× (1–10 mm²) solid or stranded, speeding panel wiring.
Integration Notes
Operating temperature range is -20 to +60 °C; storage and transport range is -50 to +80 °C. Mounting position is any. Clearance requirements: 50 mm upwards, 50 mm downwards, 30 mm at the side, zero forwards or backwards. These spacings matter for heat dissipation and arc flash containment in a panel. Rated operational voltage spans 20 to 690 V. Maximum switching frequency under AC-3 duty is 15 operations per hour — sufficient for motor starting cycles on pumps, fans, and conveyors, but not for high-cycling applications like rapid reversing.