Motor Protection Circuit Breaker for 6.3 A Loads — SIRIUS 3RV1021-1GA15
The Siemens 3RV1021-1GA15 is a SIRIUS motor protection circuit breaker rated for 6.3 A continuous current. The Class 10 trip characteristic allows motor inrush without tripping. Rated breaking capacity hits 100 kA at 400 V AC and 500 V AC, dropping to 6 kA at 690 V AC. That 100 kA figure at common distribution voltages means this breaker can be applied downstream of a transformer with high fault current without needing a current-limiting upstream device in most panel designs. The 6 kA at 690 V still covers the majority of industrial motor branch circuits at that voltage level. Phase failure detection is built in — if one phase drops on a three-phase motor, the breaker will trip rather than let the motor single-phase and overheat. Ground fault detection is not included, so a separate ground-fault relay or RCD is needed if that protection is required. Mounts on 35 mm DIN rail per DIN EN 50022 via screw and snap-on fastening. Width is 45 mm, depth 96 mm, height 97 mm. The IP20 front protection means it's safe for finger contact in an enclosed panel but not for washdown environments.
Integration — Terminal Details and Panel Fit
Screw-type terminals on both the main current circuit and the auxiliary/control circuit. Solid conductor capacity: 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). No backwards or side clearance needed — zero mm on both — which simplifies panel layout when mounting multiple units side by side. Auxiliary switch is transverse design and the product extension for an auxiliary switch is supported, so you can add a signal contact for remote status indication without replacing the breaker. Operating temperature range is -20 to +60 °C during operation; storage and transport range is -50 to +80 °C. Power dissipation at rated current in hot operating state is 7.25 W. In a dense panel with multiple breakers, that heat adds up — factor it into your enclosure thermal calculation rather than assuming zero dissipation from a protective device.
Delta — How This Sits Against the 3RV2021-1FA15
The 3RV2021-1FA15 is the closest functional peer in the SIRUS series — same form factor, same DIN rail mounting, same screw terminal architecture. The deciding difference is the continuous current rating: the 3RV1021-1GA15 is set for 6.3 A, while the 3RV2021-1FA15 covers a different current range. If your BOM specifies 6.3 A motor protection, the 3RV1021-1GA15 is the correct fit; the 3RV2021-1FA15 would require a different setting range and may not coordinate with the same upstream protective device. Panel cutout and wiring footprint are identical, so a swap is mechanically possible but electrically wrong unless the motor FLA matches the alternate's range.