What this contactor is and where it fits
The Siemens 3RT2526-2BW40 is a SIRIUS S0-frame contactor with spring-type coil terminals. It is designed for screw and snap-on mounting onto 35 mm standard mounting rail per DIN EN 50022, making it a direct fit for any standard industrial control panel. The S0 frame size means this contactor is sized for moderate motor loads and auxiliary switching duties common in conveyor, pump, and fan circuits. The spring-type coil termination eliminates the need for screwdriver torque control on the coil wiring — a time-saver during panel build and a reliability gain against vibration loosening.
Mounting and clearances — what the numbers mean for panel layout
Mounting position is flexible: +/-180° rotation on a vertical surface, plus +/-22.5° tilt forward or backward. That covers most enclosure orientations without derating. Clearances: zero mm upwards, forwards, backwards, and downwards; 6 mm at the side. This tight clearance envelope means you can pack contactors side-by-side without worrying about arc flash between phases — the 10 ms arcing time is contained within the S0 housing. Dimensions are 107 mm deep, 61 mm wide, 102 mm high — a compact footprint that leaves room for auxiliary contact blocks or a thermal overload relay alongside on the DIN rail.
Auxiliary contact ratings — switching capability across the voltage range
The built-in auxiliary switch handles 10 A at 24 V, 10 A at 230 V, and 3 A at 400 V, with ratings down to 0.1 A at 600 V. This covers PLC-level signals up to small pilot-duty loads. The solid/stranded wire capacity is 2x (0.5... 2.5 mm²), which matches standard control wiring practice. Switching frequency is rated at 5,000 cycles per hour for AC operation, with a maximum of 1,000 cycles per hour at AC-1 resistive load. DC switching timing is 15...18 ms; arcing time is 10 ms. These numbers are relevant for high-cycle applications like indexing conveyors or rapid-reversing drives.
Thermal limits and lifecycle status
Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C. The 60 °C ceiling is adequate for most ventilated enclosures, but if this contactor sits near a furnace or hot-strip mill stand, you'll want to verify the ambient at the mounting location stays under that limit. The storage range confirms it can survive cold warehouses.