What it is and what it does
The Siemens 3RT1344-1AP60 is a SIRIUS power contactor in size S3, rated for switching motor loads up to 42 kW at 230 V at 60 °C ambient — that is the AC-3 duty figure that governs real motor starts, not a resistive-heater number. Insulation voltage is rated at 1 000 V, and the contactor mounts via screw or snap-on onto 35 mm or 75 mm DIN rail, making it a direct fit into standard European-style control panels.
Terminal and wiring detail
Main current circuit terminals are screw-type, accepting solid conductors from 2x (0.5... 1.5 mm²) up to max. 2x (0.75... 4 mm²) for the auxiliary side, and stranded conductors from 2x (10... 50 mm²) for the power side. The contactor is rated IP20 on the front with a cover or box terminal; the terminal body itself is IP00, so panel builders should account for clearance and finger-safe shrouding if the enclosure door is open during commissioning.