SIRIUS 3RV1342-4FC10 — Motor Circuit Breaker for Starter Combinations
The Siemens SIRIUS 3RV1342-4FC10 is a 40 A continuous-rated circuit breaker for starter combinations. It integrates directly with a contactor to form a coordinated motor starter pair.
Zero clearance required backwards and at the side — you can butt it against adjacent devices without derating for airflow. Any mounting position is acceptable, which helps in tight enclosures where rail orientation is fixed.
Main circuit terminals are screw-type with box terminals, accepting solid conductors 2x (2.5...16 mm²) and stranded 2x (10...50 mm²) or 1x (10...70 mm²). Auxiliary and control circuit terminals are also screw-type. The part supports an auxiliary switch — order separately. Wire range covers most panel wiring up to 70 mm² on the main circuit, which is generous for a 40 A device.
Breaking capacity is 100 kA at 240 V and 400 V AC, dropping to 18 kA at 500 V and 12 kA at 690 V. At 400 V — the most common industrial voltage — the 100 kA figure means this breaker can be used on high-fault-capacity panels without requiring upstream current-limiting fuses. The rated impulse withstand voltage is 6 kV, and touch protection is finger-safe.