What this contactor is and where it lands
The Siemens 3RT2026-2AM20 is a SIRIUS power contactor in the S0 frame size, built for switching motor loads and resistive loads in industrial control panels. It lands on a 35 mm DIN rail per DIN EN 60715 — screw or snap-on — and carries spring-type terminals on the magnet coil, so no screwdriver needed for the coil connection. The main contact rating spans 18 to 8 A, covering small to mid-range motor circuits in a 45 mm wide package.
What the ratings mean for fit
The 18-8 A main contact range tells you this contactor is sized for motors drawing up to about 8 A in AC-3 duty — think 3-4 kW at 400 V three-phase. The 24 VDC coil pulls 10 A through its auxiliary contacts at rated voltage, so the control circuit needs a 24 VDC supply capable of that inrush. Switching frequency tops out at 750 operations per hour in AC-3 and AC-3e, and 1000 in AC-1 resistive loads — enough for a conveyor or pump cycling every few seconds, but not for a high-speed pick-and-place. The spring terminals on the coil accept 1 to 10 mm² solid or stranded wire; main contacts take 2x (0.5 to 2.5 mm²) fine-stranded, so panel wiring is straightforward with standard ferrules.
Panel integration and mounting
Mounts on 35 mm DIN rail per DIN EN 60715 — screw or snap-on. The S0 frame is 45 mm wide, 102 mm tall, 97 mm deep, so it fits standard enclosure backplanes. Clearance needs: 10 mm upwards, 10 mm forwards, 10 mm downwards, 6 mm at the side. The mounting position allows +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward, so it adapts to tight layouts. Operating temperature range is -25 to +60 °C; storage from -55 to +80 °C.
Switching performance and service life
Mechanical service life is 10 million operations typical — that is the contactor body itself, not the contacts under load. Electrical life depends on duty: AC-1 (resistive) at 1000 ops/h, AC-2 and AC-3 (motor start/run) at 750 ops/h, AC-4 (plugging/inching) at 250 ops/h. Arcing time is 10 ms at AC, with a 4-16 ms range. Power loss at 50 Hz is 0.25 W; at 60 Hz, 0.28 W — negligible for panel thermal budgeting.