What this contactor is and what it does
The Siemens 3RT1026-1AN64 is a SIRIUS power contactor in the compact S0 frame size, designed for switching three-phase motor loads and resistive loads in control panels. It mounts via screw or snap-on onto 35 mm DIN rail per EN 50022, fitting a 45 mm wide slot — standard for a 3-pole contactor at this rating. Rated for 11 kW at 400 V in AC-2 duty (slip-ring motor starting), it handles 15.5 A in AC-4 (plugging/reversing/inching). For resistive AC-12 loads, the maximum operating current is 10 A. These ratings define the real switching capability: AC-2 covers the moderate inrush of wound-rotor motors, while AC-4 covers the severe duty of frequent reversing or jogging. The 3RT1026-1AN64 carries two instantaneous normally-open auxiliary contacts for feedback or interlocking, and uses screw-type terminals on the main circuit. Wire range for the main contacts accepts up to 2x 10 mm² stranded or 1x 8 AWG, with a solid range of 2x (0.5 to 1.5 mm²) for auxiliary circuits.
Mounting and integration into the panel
Snap it onto a 35 mm DIN rail or screw-mount it — the S0 frame gives you both options. Side-by-side mounting is permitted with no gap, saving rail space. If you need clearance for airflow or wiring access, the required side spacing is 6 mm. Front protection is IP20 (finger-safe), while the terminal area is IP00 — meaning the connection points are live when the panel door is open. Pollution degree 3 (conductive pollution) is assumed, so the contactor is suited for industrial environments where occasional condensation or light dust is present. Operating temperature range is -25 to +60 °C, with a maximum installation altitude of 2000 m without derating. The rated operating voltage factor is 0.8 to 1.1 at 50 Hz and 0.85 to 1.1 at 60 Hz — meaning the coil holds in reliably even with a 20% voltage dip at 50 Hz.
Lifecycle and sourcing reality
For a BOM freeze or critical-spare holding, this is a low-risk line item. The mechanical life is rated at 10 million operating cycles typical, which translates to years of service in most cycling applications.