What it is and what it does
The Siemens 3RV1021-1FA10-ZW97 is a SIRIUS motor protection circuit breaker, designed for motor protection in main current circuits. It carries a continuous current rating of 5 A and a trip class of CLASS 10, meaning it will trip within 10 seconds at 7.2× the set current, matching the thermal characteristic of standard induction motors during start-up. Rated for use up to 690 V, its breaking capacity is 100 kA at 240 V, 400 V, and 500 V AC, dropping to 6 kA at 690 V. At 400 V it is rated for 1.5 kW motor load, which is the typical sizing for a small pump or fan motor. It includes phase failure detection, which is critical for preventing single-phasing damage on three-phase motors. No ground fault detection is built in — that would require an add-on module or separate GFCI.
Mounting and wiring
Mounts via screw and snap-on onto 35 mm DIN rail per DIN EN 50022. The 45 mm width means it occupies a single modular unit on the rail — standard for panel layouts. Mounting position is any, which simplifies cabinet layout. Screw-type terminals on both main and auxiliary circuits. Accepts solid or stranded conductors: 2x (1 … 2.5 mm²) and 2x (2.5 … 6 mm²), or AWG 14–10. The dual-wire capacity per terminal is useful for daisy-chaining control power or looping through the line side. Dimensions: 96 mm deep, 97 mm tall. Zero clearance required at the back or sides, so it fits tight against the backplane or adjacent devices.
Environmental and compliance
Operates from -20 to +60 °C; stores and transports from -50 to +80 °C. IP20 on the front — protected against finger contact but not water ingress, so it belongs inside a panel, not on the machine exterior. Shock rated at 25g / 11 ms. Surge voltage resistance at 6 000 V. Power dissipation is 7.25 W total in hot operating state (2.4 W per pole). RoHS compliance date is 01.05.2012.