SIRIUS S3 Power Contactor – 52 y MTBF, DIN-Rail Mounted
The Siemens 3RT2046-3SB30 is a SIRIUS-branded power contactor in the S3 frame size, designed for screw and snap-on mounting onto 35 mm DIN rail per DIN EN 60715. The MTBF of 52 years reflects a design target for continuous industrial duty — a useful benchmark for reliability calculations in safety or process-critical circuits. Mounting position allows +/-180° rotation on a vertical surface and can be tilted forward/backward by +/-22.5°, giving panel builders flexibility in tight enclosures. The contactor occupies 70 mm width by 152 mm depth by 140 mm height, with clearance requirements of 10 mm upwards, 10 mm downwards, 10 mm at the side, and 20 mm forwards for arc flash and cooling.
Switching Duty and Mechanical Endurance
Rated for 5,000,000 typical mechanical operations, the 3RT2046-3SB30 supports high-cycle applications. Maximum switching rates vary by duty: 900 1/h at AC-1 resistive, 850 1/h at AC-3 or AC-3e motor starting, 350 1/h at AC-2 slip-ring motor, and 250 1/h at AC-4 plugging/inching. These rates define the thermal limit of the contactor under repetitive load — exceeding them risks contact welding or premature wear. Auxiliary switch is included as standard. Arcing time is 10–20 ms, and the coil operates with spring-type terminals, accepting solid or stranded conductors 2x (0.5–2.5 mm²) for the control circuit.