What it is and where it fits
The Siemens SIRIUS 3RT1034-1BB44-0AA1-ZW96 is a power contactor in the S2 frame size, designed for switching motor loads in control panels. It mounts on a 35 mm DIN rail per DIN EN 50022, using either screw or snap-on fastening, and occupies 55 mm of width — a standard slot in most panel layouts. The coil is rated 24 VDC with a holding current of 10 A at that voltage, and the contactor is built for main current circuits with screw-type terminals. The front face carries an IP20 rating; the terminal area is IP00, so the panel enclosure provides the environmental seal.
What the ratings mean for your motor load
For AC-3 duty (squirrel-cage motor starting), the contactor is rated 18.5 kW at 400 V and 10 kW at 690 V. That covers a 25 hp motor on a 400 V line or a 15 hp motor on a 690 V line — common sizes for pump, fan, and conveyor drives. The AC-2 rating (slip-ring motor) is 15 kW at 400 V, and AC-4 (plugging/reversing) is 29 A at 400 V, so it handles inching and reversing cycles at that current. Switching frequency limits are 1 000 operations per hour under AC-3, 750 under AC-2, and 250 under AC-4. For high-cycle applications like a fast-indexing conveyor, the AC-3 figure is the one to watch — it allows a cycle every 3.6 seconds, which is enough for most material-handling lines.
Lifecycle and sourcing reality
The substance prohibition date (RoHS/REACH) is listed as 05/01/2012, confirming compliance with the EU directives that took effect that year. No further compliance documentation gaps exist in the record.
Wiring and integration notes
Screw terminals accept solid conductors from 2x 0.5 mm² up to 2x 4 mm², and stranded from 2x 0.75 mm² up to 2x 25 mm². For a typical motor circuit, a 4 mm² or 6 mm² stranded cable is straightforward; the 16 mm² minimum at 40 °C derating covers the high-current path if ambient is elevated. Operating temperature range is -25 to +60 °C; storage range is -55 to +80 °C. Pollution degree 3 means it tolerates conductive dust and condensation inside the enclosure — standard for industrial control rooms and machine cabinets. Mechanical life is 10 million operations typical, with arcing time between 10 and 15 ms and dropout time 20 to 30 ms at DC. Side-by-side mounting is permitted, so you can pack multiple contactors on the same DIN rail without derating for heat buildup.