Siemens 3RV2021-4AA10 SIRIUS 3RV2 Circuit Breaker S0 for Motor Protection. Circuit breaker size S0 for motor protection, CLASS 10 A-release 10...16 A N-release 208 A screw terminal Standard switching capacity. It belongs to SIRIUS 3RV2 motor starter protectors. Recorded manufacturer technical characteristics include Poles: 3; Trip class: CLASS 10; Rated current: 16 A; Breaking capacity: 55 kA at 400V; Overload release range: 11 … 16 A; Short-circuit release current: 208 A.