Motor protection breaker, 0.4 A, Class 10 — what it means on the line
The Siemens 3RV1021-0EA10-ZW97 is a SIRIUS motor protection circuit breaker rated for 0.4 A continuous current in a 3-pole configuration. Trip Class 10 means it will trip within 10 seconds at 7.2× rated current — fast enough to protect a motor winding from sustained overload but slow enough to ride through normal starting inrush on a small pump or fan. Breaking capacity is 100 kA at 400 V AC, so it can safely interrupt a bolted fault on a high-capacity distribution board without the breaker welding shut. That 100 kA holds all the way up to 690 V AC, which covers most industrial supply voltages in one device. Phase failure detection is built in — if one phase drops out, the breaker trips. That prevents single-phasing on a three-phase motor, which would otherwise draw locked-rotor current on the remaining phases and cook the winding in minutes.
Panel fit and wiring
Mounts via screw and snap-on onto 35 mm standard mounting rail per DIN EN 50022. Width is 45 mm, depth 96 mm, height 97 mm. Zero clearance needed at the sides or rear — 0 mm backwards, 0 mm at the side — so you can pack these tight on a DIN rail without derating for air gap. Screw-type terminals on both main and auxiliary circuits. Accepts solid or stranded conductors: 2× (1…2.5 mm²) and 2× (2.5…6 mm²). For AWG, 2× (14…10). Fine-stranded with core-end processing is also supported at the same cross-sections. Strip length and torque spec are standard for this terminal class — no special tooling needed. IP20 on the front — protected against finger contact but not washdown. This is a panel-interior device, not a field-mounted enclosure breaker.
Lifecycle and sourcing
RoHS compliance date is 01.05.2012, so it meets the EU substance restrictions for current installations. No explicit REACH or UL statement in the spec record, but the SIRIUS series carries IEC and UL certification as a standard — verify the specific UL file number with the order desk if your panel requires a marked UL listing.