Mounting and panel fit
The 3RT2026-1AU20: Fastens with screws or snaps onto 35 mm DIN rail per DIN EN 60715 — standard panel integration, no adapter needed. Size S0 footprint: 45 mm wide, 85 mm tall, 97 mm deep. Clearance requirements: 10 mm upwards, forwards, and downwards; 6 mm at the sides. Mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward, so you can orient it to fit the gland plate layout without fighting the rail.
Switching duty and what the ratings mean
This is a SIRIUS power contactor for motor and resistive loads. The headline numbers: 10 A switching current at 24 V, 3 hp at 230 V, 3 A at 400 V. Those are the currents it can make and break under those voltages — the 24 V figure matters for control circuits or low-voltage motor branches; the 400 V figure is what you use for a three-phase motor branch on a 400 V line. Maximum switching rates differ by duty: 1 000 cycles/hour for AC-1 (resistive), 750 for AC-2 and AC-3 (motor starting/running), 250 for AC-4 (plugging/inching). The AC-3e rating also sits at 750. If your application cycles faster than that, the contactor will overheat — the thermal limit is the constraint, not the mechanical life. Mechanical life is 10 000 000 operations typical, so the contactor will outlast the panel if you stay within the electrical ratings.
Wiring and coil
Main contacts accept solid or stranded wire from 1 to 10 mm² (roughly 16 to 8 AWG). Auxiliary contacts accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²). The magnet coil uses screw-type terminals — no push-in or spring-cage on the coil. Coil draw: 0.25 A at 50 Hz, 0.28 A at 60 Hz. Operating time on AC supply is 4 to 16 ms; arcing time is 10 ms. That arcing time is short enough that you don't need external suppression for most panels, but if you're switching inductive loads near sensitive electronics, a snubber across the contacts is cheap insurance.