SIRIUS circuit breaker for starter combinations
The Siemens 3RV2342-4RC10 is a SIRIUS circuit breaker specifically designed for starter combinations, meaning it integrates motor protection and disconnection in a single device sized for the motor branch circuit rather than a general distribution feeder. This is the part to specify when the BOM calls for coordinated motor starter protection — not a standalone MCCB for a panel main.
At 400 V AC, this breaker delivers 100 kA breaking capacity — the same high-interrupt rating it carries at 240 V AC. Motor horsepower ratings span 7.5 hp at 110/120 V up to 75 hp at 575/600 V, covering a wide range of North American motor frames. The 84 A continuous rating at 480 V and 600 V matches common motor full-load current for 60 hp and 75 hp NEMA designs respectively.
Clearance requirements: 150 mm above and below for arc venting and cable bending, 30 mm at the sides, and zero clearance forward or backward. No extra side space needed between adjacent devices. Screw-type terminals on the main circuit accept 2x (2.5 to 16 mm²) solid or stranded conductors, with a single-wire option up to 70 mm².
Environmental and voltage range
The rated voltage range is 20 to 690 V, covering low-voltage control circuits through 690 V industrial mains.