Siemens 3RT1034-3AL16 is a SIRIUS Size S2 power contactor with a 230 V 60 Hz coil, screw-type terminals, and DIN rail mounting.
For standard motor starting (AC-3), the contactor is typically applied at higher currents; the 18.5 kW motor rating at 500 V gives a practical sizing anchor for a 25 hp class induction motor on a 480 V system. Auxiliary contact ratings cover control voltages from 24 VDC (10 A) through 230 VAC (6 A) down to 220 VDC (0.3 A), so the same block can switch PLC outputs, relay coils, or indicator lamps without an interposing relay. Mechanical life is rated at 10 million operating cycles; electrical life varies by duty (AC-1 up to 1200 cycles/hour, AC-3 at 1000 cycles/hour, AC-4 derated to 250 cycles/hour).
Side-by-side mounting is permitted, so multiple contactors can pack tightly on the rail without derating — useful for compact motor control centers. Main circuit terminals accept solid wire 2x (0.25…2.5 mm²) or stranded 2x (0.75…25 mm²), with a minimum 16 mm² at 40 °C for full current rating. The screw-type termination is field-serviceable with a standard Pozidriv or flathead driver. Dimensions are 115 mm deep × 75 mm wide × 112 mm high — the Size S2 footprint fits standard 200 mm deep enclosures with clearance for wiring ducts.
Operating temperature range is -25 to +60 °C, storage from -55 to +80 °C — suitable for unconditioned warehouses and most industrial environments without derating up to 60 °C ambient.