Motor protection circuit breaker for 10 A loads
The Siemens SIRIUS 3RV1011-1JA20 is a motor protection circuit breaker rated for 10 A continuous current, sized to protect a 4 kW motor at 400 V AC. Its CLASS 10 trip characteristic means it clears overloads within 10 seconds at 7.2× rated current — fast enough to keep a motor winding below thermal damage threshold during a stall or jam. Phase failure detection is built in, so a lost phase on the line side trips the breaker rather than letting the motor single-phase and overheat. Breaking capacity is 50 kA at 400 V AC, stepping up to 100 kA at 240 V and dropping to 3 kA at 500 V, 2 kA at 690 V. That 50 kA at 400 V is the number that matters for most European industrial panels — it handles fault currents from a typical 630 kVA transformer secondary without needing an upstream fuse or current-limiting reactor. Spring-loaded terminals on both the main and auxiliary/control circuits accept 2x (0.25 … 2.5 mm²) solid or 2x (0.25 … 1.5 mm²) finely stranded with ferrules. No screwdriver torque check needed — the cage clamp holds repeatable contact force shot after shot.
DIN-rail footprint and panel integration
Width is 45 mm, height 90 mm, depth 81 mm. Zero clearance required at the sides or rear — 0 mm backwards, 0 mm at the side — so it nests tight against adjacent devices on the 35 mm DIN rail per EN 50022. Screw and snap-on mounting; any orientation is permitted. IP20 on the front means finger-safe touch protection — no live parts exposed during normal panel access. The housing is rated for shock at 25g / 11 ms, so it holds calibration in a machine-tool environment with frequent axis acceleration.