Motor-protection circuit breaker with full traceability
The Siemens SIRIUS 3RV2021-0JA20 is a motor-protection circuit breaker designed for the main current circuit, combining overload and short-circuit protection in a single device. Its Class 10 trip curve means it will disconnect within 10 seconds at 7.2× rated current — a standard match for standard induction motor starts. Rated breaking capacity reaches 100 kA at 400 V AC, which covers most industrial distribution panels without the need for upstream current-limiting fuses. Phase failure detection is built in, so a lost phase on the line side trips the breaker and protects the motor from single-phasing.
Panel integration and wiring
Mounts via screw or snap-on onto standard 35 mm DIN rail per DIN EN 60715. Size S0 footprint measures 45 mm wide, 119 mm high, 97 mm deep — a compact fit for crowded enclosures. Spring-loaded terminals on the main circuit accept 2 × (1 to 10 mm²) solid or stranded wire, reducing installation time compared to screw clamps. Any mounting position is permitted, and the ambient operating range of -20 to +60 °C covers most control-panel environments without derating. The screwdriver shaft diameter required is 3 mm (tip 3.0 × 0.5 mm) for the spring-loaded terminals.