The Siemens 3RA2110-1JA16-1AK6 is a non-fused load feeder from the SIRIUS family, designed as a direct starter in size S00. It ships as a pre-assembled unit: the supplied contactor is a 3RT2016-1AK61 and the link module is a 3RA1921-1DA00, with a thermal bimetallic overload release built in. That means one order code covers the motor-starting core — contactor, overload relay, and the mechanical/electrical link — so you are not piecing together three separate catalog numbers for a standard across-the-line start. Rated for 4 kW at 400 V AC and 7.5 kW at 690 V AC, with horsepower equivalents of 5 hp at 460/480 V and 7.5 hp at 575/600 V. The trip class is CLASS 10, so it clears a stalled-rotor condition within 10 seconds at the locked-rotor current — standard for general-purpose motor starting on pumps, fans, and compressors where the acceleration time stays under that window.
The S00 footprint is 45 mm wide, 97.1 mm deep, and 167.2 mm tall. Clearance requirements: 20 mm upward, 10 mm downward, 9 mm to the side, and zero forward or backward — so it tucks into a shallow enclosure without extra standoff. The 45 mm width means three units fit in a standard 140 mm DIN section with room for a terminal block alongside.