What this breaker does in a motor circuit
The Siemens 3RV1021-1GA15-ZX95 is a SIRIUS motor protection circuit breaker rated for 6.3 A continuous current, sized to protect a 2.2 kW motor on a 400 V three-phase line. That's the kind of thing you want on any pump, conveyor, or compressor circuit where a lost phase would mean a rewind bill. Breaking capacity runs 100 kA at 240 V, 400 V, and 500 V AC, dropping to 6 kA at 690 V.
Mounting and wiring on the rail
No tools needed for the rail; the screw terminals on both main and auxiliary circuits take solid wire from 0.5 to 1.5 mm² (two conductors per clamp) and stranded from 1.0 to 2.5 mm², with a second range up to 6 mm² for larger feeds. For AWG, main contacts accept 2x (14 to 10). The auxiliary switch is designed transverse and the product extension allows adding a separate auxiliary contact block if the built-in contacts aren't enough for your PLC feedback or status lamp.
RoHS compliance date is marked as 01.05.2012, indicating the product has been compliant with the RoHS directive since that date. Ground fault detection is not included — this is a motor protection breaker, not a residual-current device. Power dissipation in hot operating state is 7.25 W at rated current — factor that into your enclosure thermal budget if you're packing several of these on a rail.