What it is and what it does
The Siemens SIRIUS 3RT1026-3XF00-0GA0 is a power contactor in the S0 frame size, designed for switching motor loads in industrial control panels. It carries an AC-2 rating of 11 kW at 400 V, meaning it handles wound-rotor motors and slip-ring applications at that power level. For AC-4 duty — plugging and inching of squirrel-cage motors — it's rated 15.5 A at 400 V. The contactor also delivers 11 kW at both 500 V and 690 V, so it's usable across common European voltage levels without derating for the motor power. A built-in varistor provides surge suppression across the coil, which saves panel space and simplifies wiring — no separate suppressor module to mount and connect.
Mounting and panel integration
Mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 50022. The S0 frame footprint is 45 mm wide, 119 mm tall, and 100 mm deep — a compact envelope that fits standard distribution boards and motor control centers. Side-by-side mounting is permitted, so you can gang multiple contactors on the same rail without mandatory spacing gaps, which saves enclosure width. Front face carries IP20 protection — safe from finger contact during panel access. The terminal area itself is IP00, so live parts are exposed when the terminals are open; standard panel guarding applies.
Wiring and coordination
Main circuit connections use screw-type terminals accepting 2x (0.25...2.5 mm²) solid, 2x (1...2.5 mm²) stranded, 2x (2.5...6 mm²) stranded, or max 2x 10 mm². AWG equivalents are 2x (16...12), 2x (14...10), and 1x 8. This range covers typical motor feeder cables up to 6 mm² and allows paralleling two conductors per terminal for daisy-chaining. For Type 1 coordination (no damage to the contactor under short circuit, but may require replacement of the contactor), use a gL/gG fuse rated 100 A. For Type 2 coordination (contactor remains operational after clearing the fault), the fuse drops to 35 A gL/gG. The 35 A limit is the one to design by if you want to avoid swapping contactors after a fault.
Environmental and endurance ratings
Rated for pollution degree 3 — suitable for industrial environments with conductive dust or condensation. Operating temperature range is -25 to +60 °C, which covers most indoor panel conditions including warm cabinet interiors. Maximum operating altitude is 2 000 m without derating. Mechanical endurance is 10 million operations — the contactor's mechanical life before wear-out. Electrical life depends on the switching duty and load current, but the mechanical figure gives a ceiling for high-cycle applications like conveyor indexing or pump cycling.