SIRIUS 3RT6027-1AF00 — Power Contactor, Size S0
The Siemens SIRIUS 3RT6027-1AF00 is a size S0 power contactor rated for motor switching in AC-3 and AC-3e duty up to 690 V. It delivers 27.5 kW at 400 V and 47.5 kW at 690 V (both at 60 °C ambient), making it a fit for 400 V three-phase motor loads in the 25–30 kW range in control panels.
At 60 °C ambient, the contactor carries 27.5 kW at 400 V — this is the derated value for a warm enclosure, not the ideal 40 °C number. If your panel runs hot, this is the rating to size against. Mechanical life is rated at 10,000,000 operations typical, with AC-3 electrical endurance at 750 switching cycles per hour maximum. For high-duty applications like conveyor start-stop, stay under the 750 1/h ceiling to avoid contact wear. The coil draws 6 A at 24 V rated value, 10 A at 230 V, and 3 A at 400 V — these are inrush or holding currents depending on the control circuit design. Verify your PLC output or relay can source the 6 A at 24 VDC if using a 24 V control supply.
Main current circuit and auxiliary/control circuit both use screw-type terminals. Main contacts accept 2x (0.5 to 1.5 mm²) solid/stranded or 2x (0.75 to 2.5 mm²) — equivalent to 2x (16 to 12 AWG) or 2x (14 to 8 AWG). Minimum conductor size at 40 °C and 60 °C is 10 mm² for the main circuit.