The Siemens 3RT1026-1AK60-0UA0 is a SIRIUS power contactor in the S0 frame size — the middle-duty footprint in the SIRIUS family, sized for motor loads up to 11 kW under AC-2 duty at 400 V. That AC-2 rating covers slip-ring motor starting and reversing, where the contactor sees moderate inrush but regular switching under load.
AC-2 means the contactor is designed for the higher arc energy of slip-ring motor duty, where the load current stays near rated during switching. The operating temperature span is -25 to +60 °C — wide enough for unheated enclosures in northern plants or cabinet-adjacent heat from drives.