What it is and what it does
The Siemens 3RT1026-1AH20 is a SIRIUS power contactor in size S0, rated for 11 kW in AC-2 duty. Screw-type terminals handle both main and auxiliary circuits; the auxiliary contacts provide 10 A and 6 A for coil holding and signal feedback. Mounts via screw or snap-on onto a 35 mm DIN rail per EN 50022, occupying a 45 mm width – a standard slot in most control panels.
Key ratings for selection
AC-4 rating of 15.5 A defines the inching/plugging capability. Coil pickup/dropout tolerances: 0.8–1.1 × rated voltage at 50 Hz, 0.85–1.1 at 60 Hz – expect reliable hold across typical line variations.
Physical integration notes
Overall dimensions 85 mm height × 45 mm width × 91 mm depth. The front carries IP20 protection; the terminal area is IP00 – keep cable glands and panel clearance aware of the exposed terminals. Wire range: solid stranded 0.5–4 mm² (2×) for main contacts; auxiliary contacts accept 1–2.5 mm² (2×). Use ferruled stranded for easier insertion into screw clamps. Side-by-side mounting allowed without derating – stack multiple units for multi-speed or reversing starters.