What it is and where it fits
The Siemens SIRIUS 3RT2026-2XB40-1LA2 is a size S0 contactor with a 24 VDC coil, spring-type terminals on both main and auxiliary contacts, and a screw-and-snap-on mount for 35 mm DIN rail per DIN EN 60715. Rated operating temperature spans -40 to +70 °C during operation, with storage from -55 to +80 °C, so it handles unheated enclosures and outdoor-adjacent panels.
Key ratings and what they mean for fit
The 24 VDC coil draws a 3 A inrush peak and holds at 24 V nominal; at 24 V rated value the auxiliary contacts switch 10 A, derating to 2 A at 48 V and 0.3 A at 220 V — the DC switching curve matters if you're running the aux circuit at a different voltage than the coil. Mechanical life is 10,000,000 operations typical, and the contactor is rated for 750 switching cycles per hour under AC-1, AC-2, and AC-3 duty — only AC-4 drops to 250 cycles/hour, so it's built for high-duty motor starting, not just resistive loads. Spring-type terminals accept 2x (1…10 mm²) solid or 2x (0.5…2.5 mm²) stranded on the main contacts, with auxiliary contacts taking 18…8 AWG — no screwdriver torque check, just strip and push.
Mounting and clearances
Mounting position is standing on a horizontal surface; snap-on onto 35 mm DIN rail per DIN EN 60715, or screw-fasten. Clearance to adjacent devices: 10 mm upward, 10 mm forward, 10 mm downward, and 6 mm to the side — tight enough for dense panel layouts. Dimensions are 45 mm wide, 102 mm high, 107 mm deep — the S0 footprint matches other SIRIUS S0 contactors and overload relays, so a panel laid out for that family swaps without re-drilling.