What it is and what it does
The Siemens 3RV1021-1EA15-ZX95 is a SIRIUS motor protection circuit breaker designed for motor protection in control panels. It provides overload and short-circuit protection for motors up to 1.5 kW at 400 V AC, with a continuous rated current of 4 A. Trip Class 10 means it will trip within 10 seconds at 7.2× the current setting — fast enough to protect standard induction motors during a locked-rotor event without nuisance tripping on normal starts. Phase failure detection is built in, so it will drop the load if one phase is lost — critical for preventing single-phasing damage on three-phase motors.
Breaking capacity and coordination
Rated breaking capacity reaches 100 kA at 400 V AC — that's high enough for most industrial panels fed from a transformer of several hundred kVA. At 690 V AC it drops to 6 kA, so verify the available fault current at that voltage level.
Mounting and wiring
Mounts on a 35 mm DIN rail per EN 50022, screw and snap-on. Front IP20 means it's safe for finger contact inside an enclosure. Any mounting position is allowed, so panel layout is flexible. Main circuit terminals accept solid conductors 2x (0.5–1.5 mm²) and 2x (0.75–2.5 mm²), or stranded 2x (1–2.5 mm²) and 2x (2.5–6 mm²). Auxiliary and control circuits use screw-type terminals as well.
Lifecycle and sourcing
RoHS compliance date is 01.05.2012, so it meets the EU substance restrictions for current installations.