What This Part Is and Where It Goes
The Siemens 3RV1011-1KA20-ZW95 is a SIRIUS motor protection circuit breaker, designed for three-phase motor branch circuits up to 12 A continuous current and 5.5 kW at 400 V AC. It snaps onto a 35 mm DIN rail per EN 50022 and accepts spring-loaded terminals for both main and auxiliary circuits — no screwdriver torque to verify, just strip and insert. Rated breaking capacity reaches 50 kA at 400 V AC and 100 kA at 240 V AC, so it handles high-fault-current panels without cascading upstream. The Trip Class 10 characteristic means it will trip within 10 seconds at 7.2× rated current — standard for protecting standard induction motors during start-up.
Key Ratings and What They Mean for Fit
Phase failure detection is built in — if one phase drops, the breaker trips, preventing single-phasing damage to the motor. Ground fault detection is not included, so if that's required, an external ground-fault module or relay must be added downstream. The continuous current rating of 12 A sets the motor FLA it can protect. At 400 V, that corresponds to a 5.5 kW motor. The breaker also carries a 690 V rated insulation voltage and a 6 kV rated surge voltage resistance, covering most industrial supply systems. Power dissipation at rated current in hot operating state is 9.25 W total, 3.1 W per pole. In a crowded enclosure, that heat adds up — allow adequate ventilation or derating if ambient exceeds 60 °C. Mounting position is any, and the unit occupies a 45 mm wide footprint with zero clearance required at the sides or rear. The 81 mm depth fits standard 100 mm deep enclosures.
Lifecycle and Sourcing Reality
Compliance documentation includes RoHS substance prohibition dated 01.01.2013. The front face carries IP20 finger-safe touch protection.