Motor protection circuit breaker, 4 A, Class 10
The Siemens SIRIUS 3RV1011-1EA25 is a motor protection circuit breaker rated for a continuous current of 4 A, with a Class 10 trip characteristic that ensures it disconnects a stalled motor before the winding insulation degrades — critical for conveyor, pump, and fan drives where overloads develop over seconds, not minutes. It mounts on a 35 mm DIN rail per DIN EN 50022, either snapped on or screwed, and occupies a 45 mm wide footprint — one standard modular unit — so it fits a panel layout already planned around SIRIUS contactor assemblies. The spring-loaded terminals on the main circuit accept 0.25 to 2.5 mm² solid or stranded wire (24 to 14 AWG), which means no screwdriver torque check during commissioning; just strip, insert, and pull to confirm the clamp has bit.
Breaking capacity and coordination
With a breaking capacity of 100 kA at 400 V AC, this breaker can clear a bolted fault on a high-capacity distribution board without upstream fuses needing to open — that is the SCCR headroom a site electrical engineer looks for when coordinating a motor branch circuit under IEC 60947-2. At 690 V the breaking capacity drops to 2 kA, so if the panel is on a 690 V IT system the fault current must be verified against that lower figure. Phase failure detection is built in, which means a single-phased motor sees the breaker trip on the unbalance — no separate phase-monitor relay needed.
Lifecycle and sourcing
For a maintenance-spares purchaser holding a legacy cabinet full of SIRIUS 3RV breakers, this unit is a direct drop-in replacement that keeps the spare count current without re-coordination studies.
DIN-rail integration and wiring
Depth is 81 mm and height is 90 mm. Mounting position is any orientation, which helps when the panel layout forces a horizontal rail or a back-panel gland-plate constraint. IP20 on the front face means the live terminals are finger-safe once installed; the panel builder still needs a cover over the rail if the cabinet is open to unskilled access.