SIRIUS 3RV1021-1KA10-ZW96 — Motor Protection Circuit Breaker, 12.5 A
The Siemens 3RV1021-1KA10-ZW96 is a SIRIUS motor protection circuit breaker rated for 12.5 A continuous current, switching 5.5 kW at 400 V in AC-3 duty. It's a 3-pole device with screw-type terminals for main and auxiliary circuits, designed for protecting motor feeders against overload and short-circuit. The 12.5 A rating sets the thermal overload threshold. The breaker trips on overload per its Class 10 characteristic. Breaking capacity is 100 kA at 400 V AC, dropping to 42 kA at 500 V and 6 kA at 690 V. At 240 V it's also 100 kA. That 100 kA at 400 V means this breaker can safely interrupt a fault current up to that level without welding contacts or rupturing — critical for high-fault panels near large transformers.
Mounting and Integration
Mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 50022. The 45 mm width (3-module) fits standard enclosure rail. Any mounting position allowed, with 0 mm clearance needed at the sides or rear — tight panel layouts are fine. Terminals accept 2x (1 to 2.5 mm²) solid or stranded, or 2x (2.5 to 6 mm²) — covers most motor feeder cables up to 6 mm². AWG equivalent 14 to 10. Screw-type terminals on main and aux circuits; no special tooling needed. IP20 protection on the front face — suitable for enclosure-mounted breakers where the front is operator-accessible but the busbars are behind a panel door. Not for washdown environments.
Environmental and Compliance
Operating temperature range -20 to +60 °C, storage and transport -50 to +80 °C. Shock rated 25g for 11 ms — survives typical shipping and panel vibration. RoHS compliance date marked 01.05.2012 — the part meets the EU RoHS substance restrictions as of that date. Surge voltage resistance rated 6000 V, which covers the impulse withstand for standard 400 V industrial installations. Phase failure detection is built in — the breaker will trip if one phase drops out, protecting the motor from single-phasing. No ground fault detection on this variant.