What it is and what it does
The Siemens 3RV1011-1JA20-ZX95 is a SIRIUS motor-protection circuit breaker rated for 10 A continuous current and 4 kW at 400 V AC, with a CLASS 10 trip class that clears overloads fast enough to protect standard induction motors during startup without nuisance tripping. It carries a high breaking capacity — 100 kA at 240 V AC and 50 kA at 400 V AC — so it can handle fault currents on a stout utility feed without needing an upstream current-limiting fuse in most panels. Phase failure detection is built in, which means a lost leg on a three-phase motor won't go unnoticed — the breaker trips before single-phasing cooks the winding.
Mounting and wiring in the panel
Mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 50022, and the 45 mm width eats three standard module spaces on the rail — plan your gland plate and fill factor accordingly. Both main and auxiliary/control circuits terminate with spring-loaded terminals that accept 2x (0.25…2.5 mm²) solid or 2x (0.25…1.5 mm²) finely stranded with ferrules. No screwdriver torque to check, but strip length matters — the spring cage needs clean wire. IP20 finger-safe protection on the front means you can reach into a live panel without brushing busbars, but it's not sealed — keep it out of washdown zones.
Thermal and environmental limits
Operates from -20 to +60 °C and survives storage and transport from -50 to +80 °C — fine for unheated enclosures in a northern plant, but keep it out of direct sun on a hot roof. Shock-rated at 25g for 11 ms and can be mounted in any position — no derating needed if you lay the panel on its back for a skid-mounted build. Power dissipation runs 9.25 W total, 3.1 W per pole in hot operating state — factor that into your enclosure thermal budget if you're packing several breakers in a small box.