SIRIUS 3RT2025-1AC20: AC-3e Motor Contactor with 24 V AC Coil
The Siemens 3RT2025-1AC20 is a SIRIUS power contactor rated for AC-3e and AC-3 duty at 17 A, delivering 7.5 kW at 400 V across three poles. The 24 V AC coil operates at both 50 and 60 Hz, drawing 0.25 A at 50 Hz and 0.28 A at 60 Hz.
What the AC-3e Rating Means for Motor Switching
AC-3e is the enhanced version of AC-3, covering squirrel-cage motors where the contactor makes on inrush and breaks the running current. At 17 A in AC-3e, this contactor handles motors up to 7.5 kW at 400 V — the rating that governs real-world starting and stopping of pumps, fans, and compressors in a control panel. The mechanical life is 10 million operations typical, and the maximum switching rate in AC-3e is 1,000 cycles per hour — above that the contactor's thermal capacity limits the duty cycle. In AC-4 duty (plugging or inching), the maximum rate drops to 300 cycles per hour because the contactor breaks locked-rotor current on every operation.
Panel Integration and Mounting Flexibility
The S0 frame size measures 45 mm wide, 85 mm high, and 97 mm deep, fitting the standard 35 mm DIN rail per DIN EN 60715 with screw or snap-on fastening. The mounting position allows +/-180° rotation on a vertical surface and can be tilted forward or backward by +/-22.5°. Clearance requirements are 10 mm upwards, 10 mm downwards, 10 mm forwards, and 6 mm at the side — essential for heat dissipation and arc flash clearance in a crowded panel.
Wire Termination and Auxiliary Contact Ratings
Screw terminals accept solid or stranded wire from 1 to 10 mm², and two conductors per terminal are allowed: 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²). The auxiliary switch block provides 1 NO + 1 NC contact, rated 10 A at 24 V, 2 A at 48/60 V, and 0.3 A at 220 V.
Temperature Range and Operating Environment
Rated for operation from -25 to +60 °C, with storage from -55 to +80 °C — the contactor handles the thermal extremes of an unheated enclosure in a temperate climate or a hot panel near a motor.