Integrator's spec recap
The Siemens SIRIUS 3RV1021-0JA38-1KT0 is a motor protection circuit breaker designed for 1 A continuous current with CLASS 10 trip characteristics, meaning it trips within 10 seconds at 7.2× the thermal setting — standard for protecting standard induction motors during start-up. It mounts via screw or snap-on onto 35 mm DIN rail per EN 50022, takes any mounting position, and measures 45 mm wide by 97 mm high by 96 mm deep. The main circuit uses screw-type terminals accepting 2x (0.25... 2.5 mm²) solid or 2x (24... 14) AWG; the auxiliary and control circuit uses spring-loaded terminals. Phase failure detection is built in; ground fault detection is not.
Breaking capacity and duty
This breaker delivers 100 kA breaking capacity across the board — at 240 V, 400 V, 500 V, and 690 V AC — so it handles high-fault industrial panels without cascading upstream. The AC-3 motor-switching rating maxes out at 690 V, and at 400 V it's rated for 0.25 kW motor load. Maximum operating frequency in AC-3 duty is 15 operations per hour. Power dissipation in hot operating state is 7.25 W, which matters for enclosure thermal budgeting.
Auxiliary switch and environmental ratings
The auxiliary switch is transverse design and field-addable (product extension auxiliary switch is yes). Switching capacity: 1 A at 24 V, 0.15 A at 60 V, 0.5 A at 230 V. Surge voltage resistance is 6 000 V. Operating temperature range is -20 to +60 °C; storage and transport range is -50 to +80 °C. Shock resistance is 25 g for 11 ms. Front protection class is IP20 — suitable for enclosed panels, not for washdown environments.