The Siemens SIRIUS 3RT1034-3AL20-ZW97 is a size S2 power contactor rated for motor switching at 18.5 kW at 500 V in AC-3 duty, and 10 kW at 690 V in AC-3 duty. The coil is wound for 230 V at both 50 Hz and 60 Hz, with an operating range of 0.8 to 1.1 times rated voltage at 50 Hz and 0.85 to 1.1 at 60 Hz.
Side-by-side mounting is supported, so multiple contactors can be ganged without spacing gaps. Dimensions are 112 mm high, 55 mm wide, and 115 mm deep, fitting the S2 frame footprint common across the SIRIUS contactor line.
Main circuit terminals are screw-type, accepting 2x solid conductors from 0.25 to 2.5 mm², or 2x stranded conductors from 0.75 to 25 mm². The larger stranded range covers the full current capacity of the contactor without needing lug adapters.
Switching Performance and Life
Maximum switching frequency varies by duty: 1,200 cycles per hour in AC-1 (resistive), 1,000 in AC-3 (motor start/run), 750 in AC-2 (slip-ring motor), and 250 in AC-4 (plugging/inching). The AC-4 limit is the binding constraint for high-duty-cycle reversing or jogging applications.
Built-in auxiliary contacts are rated for 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, 0.3 A at 220 V, 6 A at 230 V, and 3 A at 400 V. These cover typical control circuit voltages in both 24 VDC and 230 VAC panels.