Siemens 3RT1046-1AH04 SIRIUS Power Contactor — S3, 55 kW at 500 V
The Siemens 3RT1046-1AH04 is a SIRIUS power contactor in the S3 frame size, rated for motor switching up to 55 kW at 500 V in AC-3 duty. That 55 kW figure at 500 V is the headline rating for this part — it tells you the maximum three-phase motor load it can handle under the standard IEC utilization category for squirrel-cage motors. In AC-2 at 400 V it's rated 45 kW, and in AC-4 at 400 V it's good for 80 A, so it covers slip-ring motor reversing and plugging duty as well.
Dimensions are 146 mm high, 70 mm wide, 188 mm deep — the S3 frame is a common footprint in Siemens SIRIUS contactor ranges.
Screw terminals on the main current circuit accept a wide range of conductor sizes: solid wire from 2x 0.5 mm² up to 2x 4 mm², and stranded wire from 2x 10 mm² up to 2x 50 mm². The intermediate range covers 2x 2.5 to 16 mm² for both solid and stranded. That's enough capacity for the full rated current without needing terminal adapters or reducers.
Switching Performance and Life
Electrical life depends on the load: at AC-1 (resistive) it can manage 900 operations per hour, at AC-3 (motor running) 850 ops/h, at AC-2 (slip-ring motor start) 350 ops/h, and at AC-4 (plugging/reversing) 250 ops/h. For the coil, at 24 V rated value it draws 10 A, at 60 V it draws 2 A, at 110 V it draws 1 A, at 220 V it draws 0.3 A, at 230 V it draws 6 A, and at 400 V it draws 3 A — these are the switching current ratings for the auxiliary contacts or coil circuit, not the main power path.