SIRIUS S3 power contactor — 55 kW at 500 V, screw terminals, current lifecycle
The Siemens 3RT1046-1BF40 is a SIRIUS-branded power contactor in the S3 frame size, rated for motor switching at 55 kW at 500 V AC-3 and 25.4 kW at 690 V AC-3, with an AC-4 rating of 80 A at 400 V for reversing or inching duty.
Duty-cycle and switching-life limits
Maximum operating cycles per hour vary by duty: 900/h at AC-1 (resistive loads), 850/h at AC-3 (motor starting), 350/h at AC-2 (slip-ring motors), and 250/h at AC-4 (plugging/inching). Mechanical life is typical 10 million operations; arcing time is 10 to 15 ms, and dropout time at DC is 14 to 20 ms — relevant for coordination with upstream protective devices.
Coil and auxiliary ratings
The coil is rated 110 V AC, with pickup at 80% of rated voltage (initial value 0.8) and dropout at 1.1 times full-scale value — standard for IEC contactor control circuits. Auxiliary contact ratings at 24 V DC: 10 A; at 60 V DC: 2 A; at 110 V DC: 1 A; at 220 V DC: 0.3 A; at 230 V AC: 6 A; at 400 V AC: 3 A.
RoHS compliance date is 05/01/2012; the part is manufactured by Siemens under the SIRIUS product brand.
Termination and wiring capacity
Solid conductors accepted: 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), max 2x (0.75 to 4 mm²). Stranded conductors: 2x (10 to 50 mm²) for power connections, and 2x (2.5 to 16 mm²) for auxiliary circuits. Dimensions: 146 mm height, 70 mm width, 152 mm depth — the depth figure matters for enclosure depth selection when using box terminals.