Siemens 3RT2526-1AL20 SIRIUS Contactor — 230 V Coil, S0 Frame
The contactor mounts via screw or snap-on onto 35 mm DIN rail per EN 50022, and the mounting position allows ±180° rotation on a vertical surface plus ±22.5° tilt forward or backward — useful when panel layout forces an unconventional orientation. An integrated auxiliary switch is included (screw-type terminals), saving a separate aux block on simple forward-reverse or star-delta circuits. The auxiliary contacts are rated 10 A at 24 V, 10 A at 230 V, and 3 A at 400 V, covering pilot-duty and PLC-input signaling.
The S0 frame size is Siemens' compact motor-contactor footprint. Switching frequency is spec'd at 1,000 operations per hour for AC-1 resistive loads and 1,500 per hour for DC loads. The AC arcing time ranges from 4 to 16 ms. The -25 °C lower limit means it is not rated for deep-freeze or arctic outdoor cabinets without a heater; for standard indoor panels it is fine. That zero-clearance on five faces means the contactor can be packed tightly against other devices in a multi-row DIN rail assembly, saving panel width.
Because the coil voltage (230 V 50/60 Hz) and the integrated auxiliary switch are fixed in the order code, a buyer replacing a failed unit should match the full 3RT2526-1AL20 string — not just the base 3RT2526 frame — to avoid a coil-voltage mismatch or missing aux contacts.
Wiring and Integration Notes
The screw-type coil and auxiliary terminals accept 2x (0.5 to 1.5 mm²) solid or 2x (0.75 to 2.5 mm²) stranded conductors. For panel builders, that means two conductors per terminal are allowed — useful for daisy-chaining control voltage to multiple contactors without a separate terminal block. Dimensions: 85 mm high, 61 mm wide, 97 mm deep. The 61 mm width is the S0 standard, so it fits alongside other S0 devices (overload relays, contactor assemblies) on the same DIN rail without spacing adapters.