The Siemens 3RT6026-1KF40 is a SIRIUS coupling contactor in the S0 frame size — a 45 mm wide, 85 mm tall, 151 mm deep unit that screws or snaps onto 35 mm DIN rail per DIN EN 50022. It is a current-production part (lifecycle stage: current) and sits in the panel as an interface between a control signal and a load circuit, typically switching motor loads up to 23 kW at 400 V or 40 kW at 690 V in AC-3 duty.
The coil is rated 110 V (the rated value), drawing 6 A at 24 V, 1 A at 110 V, and 0.3 A at 220 V — these are the inrush or hold currents depending on the control voltage applied. A built-in varistor surge suppressor is wired across the coil, so you don't need to add an external snubber for inductive load switching; just verify polarity if your control circuit uses DC.
Switching frequency and endurance
Maximum mechanical switching rate is 10,000,000 cycles typical. Electrical switching frequency depends on duty: 1,000 cycles/hour at AC-1 (resistive), 750 cycles/hour at AC-3 or AC-3e (standard motor start/run), 250 cycles/hour at AC-4 (plugging/inching), and 1,500 cycles/hour at DC. For a high-cycle conveyor or pump application, stay within the AC-3 limit of 750 ops/hour to keep contact life predictable.
Pollution degree 3 (industrial environment with conductive pollution).
Terminals and wiring
Both main and auxiliary/control circuits use screw-type terminals. Main contacts accept 2x (0.5…1.5 mm²) or 2x (0.75…2.5 mm²) solid or stranded, or AWG 2x (16…12) and 2x (14…8). Minimum cross-section is 10 mm² at both 40 °C and 60 °C ambient. Insulation voltage is rated 690 V, with AC-3/AC-3e maximum operating voltage also 690 V.