Siemens 3RT2026-1BB40 is a SIRIUS power contactor in size S0, with a 24 V coil, screw-type terminals, and mechanical life of 10 million operations. At AC, switching frequency is 5 000 1/h.
Key ratings and what they mean
The coil holds at 24 V rated value; verify coil suppression polarity when using free-wheel diodes for inductive loads. The mechanical life figure of 10 million operations translates to roughly 5.7 years of continuous cycling at 1 Hz – a solid baseline for maintenance planning. Wire acceptance: solid or stranded conductors from 1 to 10 mm². For fine-stranded or twin wires, use 2x (0.5...1.5 mm²) or 2x (0.75...2.5 mm²) per terminal – relevant when terminating control transformers or auxiliary cables. Mounting on 35 mm DIN rail (screw and snap-on) with a 45 mm width, 85 mm height, and 107 mm depth. Clearance required: 10 mm upwards, forwards, and downwards; 6 mm to the side. The unit can be rotated ±180° on a vertical surface and tilted up to ±22.5°.