The Siemens 3RV1021-1CA10-ZW98 is a SIRIUS motor-protective circuit breaker rated for 2.5 A continuous current with a CLASS 10 trip characteristic, meaning it will trip within 10 seconds at 7.2× rated current — fast enough to protect standard induction motors during a locked-rotor event without nuisance tripping on normal startup inrush. Breaking capacity hits 100 kA at 400 V AC, so it can interrupt a bolted fault up to that level without welding contacts or cascading failure upstream — useful for high-fault panels near large transformers. Snap it onto a 35 mm DIN rail per EN 50022 with zero clearance needed at the sides or rear, which lets you pack breakers tight in a crowded enclosure without derating for air gap.
What the ratings mean for fit
The 2.5 A continuous rating and 0.75 kW at 400 V AC-3 tell you this breaker is sized for a small motor — think a 1 HP pump or a fractional-horsepower conveyor drive. The CLASS 10 trip ensures it clears a locked rotor before the motor winding insulation degrades. Phase failure detection is built in, so if one phase drops on a three-phase motor, the breaker opens on the remaining two phases before single-phasing cooks the winding. No ground-fault detection here — that's handled separately downstream if needed. Screw terminals on both main and auxiliary circuits accept solid or stranded wire from 1 to 6 mm² (14–10 AWG), which covers standard motor leads and control wiring without needing adapter ferrules. The 45 mm width and 96 mm depth fit a standard 1-module footprint on the DIN rail, and the IP20 front face keeps fingers out while mounted in an enclosed panel.
Lifecycle and sourcing reality
RoHS compliance date is 01.05.2012, meaning it meets the EU substance restrictions that went fully effective in 2011. No REACH or UL listing is on record here, but the SIRIUS series typically carries UL/CSA certification for North American panels — verify the specific listing against your local code if that's a gate.
Integration notes
Mounts in any position on a 35 mm DIN rail per EN 50022, screw or snap-on. Zero clearance at sides and rear means you can abut breakers without spacing — useful when you're filling a 600 mm-wide enclosure and every millimeter counts. Auxiliary switch extension is supported, so you can add a signal contact for remote status or PLC input without rewiring the main circuit. The auxiliary terminals are screw-type, same as the main circuit. Power dissipation is 7.25 W total hot (2.4 W per pole), which matters for thermal rise in a sealed enclosure — factor that into your cabinet cooling calc if you're stacking a row of these.