The Siemens 3RV2041-4FA10-0DA0 is a SIRIUS S3 circuit breaker designed for system protection — meaning it sits upstream of a motor starter or feeder, not inside the starter itself. Rated 40 A at AC-3 (motor switching duty) up to 690 V maximum, this breaker handles the full-load current of a motor in that range and interrupts a fault up to 65 kA at 400 V AC — enough for most industrial panel SCCR requirements. The S3 frame size means it physically fits alongside the matching SIRIUS contactor and overload block in a coordinated starter assembly.
The interrupting ratings span the voltage range you'll see in a plant: 100 kA at 240 V AC, 65 kA at 400 V AC, 12 kA at 500 V AC, and 5 kA at 690 V AC. The 30 kA rating at 400 V (listed separately) likely reflects the conditional SCCR when the breaker is paired with a specific upstream device; the 65 kA is the unconditional rating.
Panel integration — mounting, terminals, and clearances
The S3 frame is 70 mm wide, 165 mm tall, and 176 mm deep — that depth includes the screw terminals and any protruding cable. Main circuit terminals accept solid or stranded copper: 2x 2.5 to 16 mm² for the smaller conductor range, and 1x 10 to 70 mm² for the larger. The main contact screws are M8. That's a generous lug — sized for the 40 A rating with headroom for the full SCCR.
Operating environment and duty cycle
Mechanical endurance is typical 25,000 operations for the main contacts and auxiliary contacts.