What it is and where it lands
The Siemens SIRIUS 3RT2026-1BB40-ZW97 is a size S0 power contactor with a 24 VDC magnet coil and screw-type terminals, carrying an integrated auxiliary switch. It snaps onto a 35 mm DIN rail per DIN EN 60715 or screws directly to the panel backplate — the S0 frame at 45 mm wide fits a standard 4-module slot on the rail. Operating range covers -25 to +60 °C, storage down to -55 °C, so it handles the ambient heat near a motor control center or a drive cabinet without derating for temperature.
What the ratings mean for fit
The coil picks up at 0.8 × rated (19.2 VDC) and drops out at 1.1 × rated (26.4 VDC) — a standard 24 VDC control supply with 10 % ripple keeps it sealed. Main contacts accept solid or stranded wire from 1 to 10 mm² (roughly 16 to 8 AWG), and the auxiliary contact block takes 2 × 0.5 to 2.5 mm². Arcing time sits at 10 ms for AC loads and 15 to 18 ms for DC; that 18 ms DC arc is the figure to check if you are switching inductive DC loads on the auxiliary contact. Clearance spacing: 10 mm upwards, downwards, and forwards, 6 mm at the sides. On a DIN rail with adjacent contactors, that 6 mm side gap is tight — verify the arc-chamber vents are not blocked if you are packing S0 frames side-by-side at high switching frequencies. Mechanical life is rated at 10 million operations typical. Electrical life depends on duty: AC-1 (resistive) allows 1 000 ops/h, AC-2 and AC-3 (motor starting) cap at 750 ops/h, and AC-4 (plugging/inching) drops to 250 ops/h. For a conveyor drive cycling at 30 starts per hour, this contactor will outlast the motor overhaul interval.
Mounting and panel integration
Mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward or backward — useful when the contactor sits on a swing-out panel or a slanted gland plate. The screw-and-snap DIN rail method is standard: hook the top clip, rotate down, and snap the bottom latch. No tools needed for the rail; the screw mount requires a 4.5 mm drill pattern.