What this part is and what it does
The Siemens 3RV1021-0GA10-ZW97 is a SIRIUS motor protection circuit breaker rated for 0.63 A continuous current, Trip Class 10, with a 100 kA breaking capacity at 400 V AC — enough to clear a hard fault on a small motor branch without upstream drama. It's a three-pole unit with screw-type terminals on both main and auxiliary circuits, and it includes phase failure detection as standard. No ground fault detection here; that's a separate add-on if you need it. Rated for 0.18 kW at 400 V, this breaker is sized for fractional-horsepower motors — think small pumps, fans, or conveyor drives in a control panel. The 100 kA SCCR at 400 V means it safely interrupts faults up to that level without cascading upstream, so you can keep the feeder breaker smaller.
Mounting and integration
Snaps onto a 35 mm DIN rail per DIN EN 50022 — standard panel fare. The 45 mm width and 96 mm depth fit a single module slot, so it won't eat up rail space. Screw terminals accept 2x (1…2.5 mm²) solid or stranded, or 2x (2.5…6 mm²) for the main circuit; auxiliary and control terminals use the same screw-type format. No backward clearance needed, and side clearance is 0 mm — you can pack them tight. IP20 on the front means it's protected against finger contact but not washdown — fine inside a closed enclosure, not for wet environments. Operating temperature range is -20 to +60 °C; storage and transport handle -50 to +80 °C. Shock rated at 25g / 11 ms, so it survives shipping and moderate vibration on a machine.
Lifecycle and sourcing reality
If you're looking at a panel originally built around the 3RV1011-0GA10, the 3RV1021-0GA10-ZW97 is a direct functional drop-in — same DIN footprint, same terminal layout, same Trip Class 10. The main difference is the higher breaking capacity (100 kA vs the older series' lower rating), which gives you more fault-clearing headroom without rewiring.