The 3RA2140-4MB47-0NB3 is a Siemens SIRIUS non-fused motor starter, size S3, designed as a direct starter for three-phase motors up to 45 kW at 400 V AC-3 duty. It ships as a factory-assembled combination of a 3RT2047-1NB30 contactor and a 3RA2942-1AA00 link module with a thermal bimetallic overload relay, all pre-wired and coordinated — no separate selection of contactor and overload needed. Rated for AC-3 switching up to 690 V, it handles 96 A at 480 V and 99 A at 600 V, covering common North American and IEC motor voltages without a second variant.
Mounting, clearances, and panel integration
Snap-mounts vertically onto a DIN rail or can be screw-mounted using the optional push-in lug — the S3 footprint (332 mm high, 70 mm wide, 200 mm deep) fits standard 600 mm deep enclosures with room for gland plates. Minimum clearances: 50 mm above, 32 mm in front, 10 mm below, and 10 mm at the sides — no rear clearance needed, so it can sit against the back panel. Main power wiring accepts stranded conductors from 10 to 70 mm² (or two parallel runs of 2.5 to 50 mm²), matching typical motor cable sizes for this current range.