The Siemens SIRIUS 3RV1021-4BA15-ZW96 is a motor protection circuit breaker rated for 20 A continuous current with a CLASS 10 trip characteristic, sized for a 7.5 kW motor at 400 V AC-3 duty.
Screw-type terminals on the main circuit accept solid conductors from 0.5 to 1.5 mm² (two per clamp) and stranded from 1 to 6 mm² (two per clamp).
Shock resistance is 25 g for 11 ms — adequate for most industrial machinery but not for high-vibration rotating equipment without additional damping. Maximum altitude 2 000 m without derating. Power dissipation in hot operating state is 10.5 W at rated current.
Switching capacity and auxiliary contacts
Breaking capacity varies by voltage: 100 kA at 240 V AC, 50 kA at 400 V AC, 10 kA at 500 V AC, and 4 kA at 690 V AC. The auxiliary switch is transverse design with no factory-fitted auxiliary contacts (0 provided); the transverse slot accepts add-on blocks if needed. Auxiliary contact ratings: 1 A at 24 V, 0.5 A at 230 V, 0.15 A at 60 V. Maximum switching frequency in AC-3 duty is 15 operations per hour.