Integrator's quick-fit note
The Siemens 3RT1344-1AN20 is a SIRIUS S3 power contactor rated 42 kW at 230 V, 60 °C — sized for motor switching in a standard 400 V three-phase panel. Screw-type main terminals accept stranded 2x (10... 50 mm²) or solid 2x (0.5... 1.5 mm²) through 2x (0.75... 4 mm²). Mounts via screw or snap-on onto 35 mm or 75 mm DIN rail; side-by-side mounting is supported, so no derating gap needed in a multi-contactor row. IP20 on the front with cover or box terminal; the terminal body itself is IP00, so panel builders should account for clearance to live parts.