What it is and what it does
The Siemens 3RT1046-1AV04 is a SIRIUS power contactor in Size S3, designed for switching motor loads in industrial control panels. It carries a 55 kW rating at 500 V in AC-3 duty, which is the standard category for squirrel-cage motor starting — so this contactor handles the inrush and breaking of motor current under running conditions, not just resistive loads.
Key ratings and what they mean for fit
The AC-3 rating of 55 kW at 500 V is the headline number for motor switching. At 400 V, the same contactor is rated 45 kW in AC-2 duty (slip-ring motor starting) and 80 A in AC-4 duty (plugging/reversing/inching). That AC-4 current matters if your application does frequent reversing or jogging — the contactor is sized for the thermal stress of those cycles, not just the run current. Mechanical life is 10 million operations typical, and the maximum switching rates are 900 cycles/hour at AC-1, 850 at AC-3, and 250 at AC-4. For a conveyor line cycling every 30 seconds, the AC-3 rate gives headroom; for a press that reverses every 10 seconds, check the AC-4 rate against your duty cycle. The coil operates on 50 Hz with a voltage tolerance of 0.8 to 1.1 times the rated value. Arcing time is 10 to 15 ms, and the contactor opens in 10 to 25 ms at AC — fast enough for most motor protection coordination schemes.
Where it goes and how it mounts
Mounts via screw or snap-on onto 35 mm and 75 mm standard DIN rail. The S3 footprint is 70 mm wide, 146 mm high, and 188 mm deep — that depth includes the screw-type terminals on the main circuit. Side-by-side mounting is allowed without derating for current, which saves rail space in multi-contactor panels. Terminals accept solid conductors up to 4 mm² (2x) and stranded up to 50 mm² (2x). The main circuit uses screw-type terminals; the auxiliary/control circuit uses the same screw clamp. Pollution degree 3 means it's rated for industrial environments with conductive pollution — no need for an extra enclosure in most panel conditions.
Protection and environment
The enclosure is IP20 on the front with the cover or box terminal fitted; the terminal area itself is IP00. That's standard for panel-mounted contactors — not for washdown or outdoor use. Operating temperature range is -25 to +60 °C, storage from -55 to +80 °C. In a steel mill near the rolling stands, the +60 °C operating limit means it can sit in a warm cabinet but not directly above a furnace. The contactor is RoHS compliant with a substance prohibition date of May 1, 2012. Compliance documentation (RoHS, REACH) is typically available from Siemens on request for the SIRIUS series.