SIRIUS S0 Power Contactor with 24 VDC Coil
The Siemens 3RT2027-2BB40-ZW96 is a SIRIUS-branded power contactor in the S0 frame size, designed for switching motor loads and resistive loads in industrial control panels. It mounts on a 35 mm DIN rail per EN 60715, with screw and snap-on fastening, and accepts solid or stranded conductors from 1 to 10 mm² on the main circuit.
Duty-Cycle Capacity and Switching Frequency
Switching frequency depends on the load category: 1 000 operations per hour for AC-1 resistive loads, 750 per hour for AC-2 and AC-3 motor starting, and 250 per hour for AC-4 plugging or inching duty. The AC-3e rating also allows 750 operations per hour. These limits reflect thermal recovery of the contactor — exceeding them shortens electrical life or risks contact welding. For the auxiliary switch, mechanical life is rated at 10 million operations typical.
Mounting and Environmental Tolerances
The contactor occupies a 45 mm wide footprint on the DIN rail, with a depth of 107 mm and height of 102 mm. Clearance requirements: 10 mm upward, 10 mm forward, 10 mm downward, and 6 mm at the sides. The mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward or backward — useful when fitting into tight enclosures or angled subpanels. Storage temperature range is -55 to +80 °C.
Terminal and Wiring Details
Coil and main terminals use spring-type (spring-cage) connections. The main circuit accepts solid or stranded wire from 1 to 10 mm²; the auxiliary circuit can take 2× (0.5 to 2.5 mm²). Spring-cage terminations reduce wiring time and resist loosening from vibration — a practical advantage in panel builds or on mobile equipment.