The Siemens 3RV2021-0FA10-0DA0 is a SIRIUS 3RV2 circuit breaker in size S0, configured for system protection — meaning it guards a motor branch circuit against overload and short-circuit, but without phase-failure detection. The A-release (overload trip) is set at 0.35 to 0.5 A, and the short-circuit release fires at 6.5 A. This makes it the right fit for small motor loads or control transformers in that current window. Screw terminals and standard switching capacity keep it a straightforward replacement in existing panels — no special tooling or derating needed for most 400 V industrial feeds.
RoHS compliant since October 2009, with REACH candidate-list disclosure on file. Export controls are AL: N / ECCN: EAR99, so no special licensing for cross-border shipments.
The 103 x 103 x 50 mm footprint matches the standard SIRIUS 3RV2 cutout — direct swap for any S0-frame protector in the family.