Motor Protection Circuit Breaker, CLASS 10
The Siemens 3RV2021-4EA10-ZW96 is a SIRIUS motor protection circuit breaker designed to protect motors against overload and short-circuit. It carries a CLASS 10 trip characteristic, meaning it will trip within 10 seconds at 7.2× the thermal setting, matching the heating curve of standard induction motors during a locked-rotor event. Rated for 25 kA breaking capacity at 400 V, it clears line-side faults up to that level without upstream fusing. The unit also provides phase-failure detection, so a lost phase on a three-phase motor will trip within the thermal curve. Mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 60715. The 45 mm width fits standard panel spacing; depth is 97 mm, with 50 mm clearance required above and below, zero forwards or backwards, and 30 mm at the sides.
Wiring & Integration
Main circuit terminals are screw-type, accepting 2×(1–2.5 mm²) or 2×(2.5–10 mm²) solid or stranded conductors. Terminal screws are M4. Mounting position is any orientation, which simplifies panel layout. Operating temperature range is –20 to +60 °C; storage and transport range is –50 to +80 °C. The unit is rated for a maximum of 15 switching operations per hour under AC-3 duty.