Siemens SIRIUS 3RT2026-1AU00 — S0 Power Contactor with Auxiliary Switch
It is rated for 3 hp at 230 V and includes an integrated auxiliary switch, making it suitable for applications requiring feedback or interlocking.
Duty-Class Switching Frequencies and Mechanical Life
The 3RT2026-1AU00 is rated for different maximum switching frequencies depending on the duty class: 1,000 cycles per hour at AC-1 (resistive loads), 750 cycles per hour at AC-2 and AC-3 (slip-ring and squirrel-cage motors), and 250 cycles per hour at AC-4 (plugging, inching). The AC-3e rating also allows 750 cycles per hour. Mechanical service life is typical 10,000,000 operations, meaning the contactor can handle high-throughput applications like conveyor lines or pump stations without premature wear.
Auxiliary Contact Ratings Across Voltages
The built-in auxiliary switch is rated for 10 A at 24 V, 2 A at 48 V and 60 V, 1 A at 110 V, 0.9 A at 125 V, 0.3 A at 220 V, 3 A at 400 V, 0.6 A at 440 V, and 21 A at 480 V. These ratings allow the auxiliary contacts to handle both low-voltage PLC signals and higher-voltage interlocking circuits, though the 480 V rating stands out — it supports direct 480 V control circuits common in North American panels.
Mounting, Wiring, and Environmental Limits
The contactor accepts solid or stranded conductors from 1 to 10 mm², with dual-wire capability: 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²). Main contacts use screw terminals sized for 16 to 8 AWG.
Coil and Switching Dynamics
The magnet coil uses screw-type terminals. Holding power at 50 Hz is 0.25 VA. Closing time at AC is 4 to 16 ms; arcing time is 10 ms. These fast switching times suit applications requiring rapid load cycling, such as resistance welding or motor jogging.