Product identity and sourcing posture
The Siemens 3RT2028-1AP60 is a SIRIUS power contactor in the S0 frame size, with a 24 VDC magnet coil terminated via screw-type terminals. The contactor mounts via screw fixing or snap-on onto 35 mm DIN rail per DIN EN 60715, fitting standard panel layouts.
Switching frequency and duty ratings
Maximum mechanical switching rate is 1 000 1/h under AC-1 resistive load, dropping to 750 1/h for AC-2 and AC-3 motor duty, and 250 1/h for AC-4 plugging or inching service. These duty-specific limits govern the thermal cycling of the main contacts — exceeding them in a motor-start application accelerates contact wear, particularly under AC-4 where the contactor makes and breaks locked-rotor current.
Mounting and environmental tolerances
Mounting position allows +/-180° rotation on a vertical surface and +/-22.5° forward/backward tilt, giving flexibility in tight enclosures. Clearance distances: 10 mm upwards, forwards, and downwards; 6 mm at the side — these are the minimum air gaps to maintain rated insulation. Operating temperature range is -25 to +60 °C; storage range extends from -55 to +80 °C.
Wiring and auxiliary contact provisions
Main and coil terminals accept solid or stranded conductors from 1 to 10 mm², with dual-wire capability for 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) on the coil circuit. The contactor includes an auxiliary switch block, allowing local status feedback without a separate add-on module.