What this SIRIUS contactor is and where it fits
The Siemens 3RT1026-1AG24 is a SIRIUS power contactor in the Size S0 frame, rated for motor switching at 11 kW in AC-2 duty at 400 V and 15.5 A in AC-4 duty at 400 V. The 24 VDC coil draws its holding current from a standard control transformer or PLC output. Screw and snap-on mounting onto 35 mm DIN rail per EN 50022 means it drops into any standard panel — no adapter plate needed. The 45 mm width and 85 mm height leave room for auxiliary contact blocks or a thermal overload relay alongside on the same rail. The AC-2 rating (11 kW at 400 V) covers wound-rotor motor starting and reversing — the duty cycle that demands the contactor handle both starting and plugging currents without accelerated wear. For heavy jogging or inching, the AC-4 rating (15.5 A at 400 V) gives the current limit for frequent plugging and reversing. The 10 million mechanical cycles typical backs the reliability expectation for a line-side spare that sits in the cabinet for years before it sees a fault.
Coordination and wiring constraints
Type 2 coordination (no weld, no damage to the contactor after a short-circuit fault) requires a gL/gG fuse rated 35 A upstream. Type 1 coordination (contactor may need replacement after a fault, but the circuit is cleared safely) allows a 100 A gL/gG fuse. The main circuit terminals accept screw-type connections: solid or stranded wire from 2x (0.5 to 1.5 mm²) up to max 2x (0.75 to 4 mm²), with the larger AWG range at 2x (16 to 12), 2x (14 to 10), or single 8 AWG. That covers most panel wiring from control to motor feeder. Side-by-side mounting is permitted with a 6 mm gap to the side, so you can pack three or four of these on a 35 mm rail without derating the stack. The front face carries IP20 protection; the terminal area is IP00, meaning the panel door or a cover must guard against accidental contact. Operating temperature spans -25 to +60 °C, which covers most indoor panel environments.