The Siemens 3RV1021-1JA15-ZW95 is a SIRIUS motor protection circuit breaker designed for motor protection, rated at 10 A continuous current with a CLASS 10 trip characteristic, meaning it will trip within 10 seconds at 7.2× rated current — fast enough to protect standard induction motors during locked-rotor conditions. It mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 50022, fitting a 45 mm wide footprint with 96 mm depth and 97 mm height, and accepts screw-type terminals for the main circuit. The breaker includes an auxiliary switch (transverse design) and provides phase failure detection, but no ground fault detection.
Breaking capacity and motor power
Breaking capacity reaches 100 kA at 240 V AC and 400 V AC, 42 kA at 500 V AC, and 6 kA at 690 V AC — sufficient for high-fault industrial panels. Motor power rating is 4 kW at 400 V AC-3, with a maximum switching frequency of 15 operations per hour at AC-3 duty. Rated insulation voltage is 690 V; the auxiliary contacts switch 1 A at 24 V, 0.5 A at 230 V, and 0.15 A at 60 V.
Operates from -20 °C to +60 °C, stores and transports from -50 °C to +80 °C, and is rated for altitudes up to 2,000 m. Front face is IP20; mechanical endurance of the main contacts is 100,000 operations typical.
Terminal capacity
Screw terminals accept solid conductors: 2×(0.5…1.5 mm²) and 2×(0.75…2.5 mm²); stranded: 2×(1…2.5 mm²) and 2×(2.5…6 mm²).