The Siemens 3RT2027-2NF30 is a SIRIUS power contactor in the S0 frame size, designed for switching motor loads in control panels. It uses spring-type terminals for the magnet coil and is rated for a coil voltage of 95–130 V AC. The contactor mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 60715, with a mounting position flexibility of ±180° rotation and ±22.5° tilt on a vertical surface.
Ratings and what they mean for the panel
The AC-3 maximum switching frequency of 750 1/h means this contactor is suited for standard motor starting duty — think conveyors, pumps, compressors — without overheating the coil or arc chamber. The AC-4 maximum of 250 1/h covers inching or plugging applications, so if your line does frequent reversing or jogging, stay within that lower cycle rate. The arcing time is a tight 10–10 ms, which keeps contact erosion predictable during fault clearing. Auxiliary contacts are built in (the auxiliary switch is present), so you don't need a separate add-on block for basic feedback to the PLC. The main contact wire range accepts solid or stranded conductors from 1 to 10 mm², and the auxiliary terminals accept 2x (0.5–2.5 mm²) — enough for standard control wiring.
Panel integration notes
The S0 frame size (width 45 mm, height 102 mm, depth 107 mm) fits standard 35 mm DIN rail enclosures. The coil holds at 95–130 V AC; dropout occurs below the initial value of 0.7 times rated voltage. Allow 10 mm clearance above and below for arc-chamber ventilation, and 6 mm at the sides for heat dissipation.