Motor protection circuit breaker for 5 A loads
The Siemens SIRIUS 3RV1021-1FA15-ZW97 is a motor protection circuit breaker designed for 5 A continuous rated current, with a Class 10 trip characteristic that clears overloads before motor windings overheat — critical for standard induction motor starting profiles. Rated breaking capacity reaches 100 kA at 240 V, 400 V, and 500 V AC, dropping to 6 kA at 690 V AC — the 100 kA figure at 400 V means it can handle high-fault utility feeds common in industrial distribution without cascading upstream. Phase failure detection is built in, so a lost phase on a three-phase motor load triggers a trip — this prevents single-phasing damage that can burn out a motor in minutes. Mounts via screw or snap-on onto 35 mm DIN rail per EN 50022, fitting standard panel layouts. The IP20 front enclosure protects against finger contact in control cabinets.
Integration and wiring
Screw-type terminals on the main current circuit accept solid conductors: 2x (0.5…1.5 mm²) and 2x (0.75…2.5 mm²). Stranded conductors: 2x (1…2.5 mm²) and 2x (2.5…6 mm²). The transverse auxiliary switch design provides a compact side-mounted contact block. Rated insulation voltage is 690 V, with operating temperature from -20 to +60 °C and storage/transport from -50 to +80 °C. Shock rated at 25g / 11 ms — suitable for machine-mounted panels near vibrating equipment. Dimensions: 45 mm wide, 97 mm high, 96 mm deep. Zero clearance required at the sides or backwards — panels can be packed tightly without derating spacing. Auxiliary switch contacts rated: 1 A at 24 V, 0.5 A at 230 V, 0.15 A at 60 V — sufficient for signaling to a PLC input or status lamp.