What It Is & Where It Goes
The 3RT2027-1AU20: This is a Siemens SIRIUS power contactor, frame size S0, designed for switching motor loads and resistive loads in industrial control panels. The 24 VAC 50/60 Hz coil draws 0.25 A at 50 Hz and 0.28 A at 60 Hz — a standard control voltage that matches most PLC or relay outputs in European and North American panels. The screw-type terminals on the magnet coil accept solid or stranded wire from 1 to 10 mm², which covers most control-circuit wiring up to 6 AWG.
Mounting & Integration
Mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 60715. The 45 mm width and 85 mm height fit standard S0 contactor spacing in a panel. Mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward/backward — useful when the panel layout is tight. Clearance: 10 mm upwards, 10 mm forwards, 10 mm downwards, 6 mm at the side. Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C.
Switching Performance & Duty Cycles
Rated for 1 000 000 electrical operations typical. Maximum switching frequency varies by duty: 1 000 cycles/hour for AC-1 (resistive), 750 cycles/hour for AC-2 and AC-3 (motor starting/running), and 250 cycles/hour for AC-4 (plugging/inching). Arcing time is 10 ms. For a bottling line or conveyor running at moderate start frequency, the AC-3 rating of 750 cycles/hour is the relevant limit — it means the contactor can handle a start every ~5 seconds without overheating the arc chamber.
Auxiliary & Main Contact Configuration
Includes an auxiliary switch block. Main contacts accept wire sizes 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²). The S0 frame matches the 3RT2027-1AP60 for mechanical fit.