The Siemens 3RV1021-1HA10-ZX95 is a SIRIUS motor protection circuit breaker rated for 8 A continuous current with a Trip Class 10 thermal-magnetic trip curve, sized for a 3 kW motor at 400 V AC. Its 100 kA breaking capacity at 400 V AC means it can safely interrupt a bolted fault on a high-capacity distribution board without the upstream breaker having to clear it — that's the SCCR headroom a site electrical engineer needs when coordinating a panel's fault rating.
Compared to the 3RV1011-1HA10, the 3RV1021-1HA10-ZX95 shares the same 45 mm width and 35 mm DIN-rail snap-on footprint, so it drops into a panel specified around the older sibling without rewiring. The key difference is the 3RV1021's higher breaking capacity — 100 kA at 400 V versus the 3RV1011's lower rating — making it the better fit for a panel with a high available fault current.
Mounts via screw and snap-on onto a 35 mm standard mounting rail per DIN EN 50022, in any position. The 45 mm width and 96 mm depth fit a standard 45 mm-wide DIN-rail slot — no extra side clearance needed (0 mm backwards, 0 mm at the side). Screw-type terminals on both main and auxiliary circuits accept solid or stranded wire: 2x (1…2.5 mm²) and 2x (2.5…6 mm²), or AWG 14–10. IP20 on the front means it's protected against finger contact but not washdown — keep it inside the enclosure.