The Siemens 3RT1044-3KF44-0LA0 is a SIRIUS power contactor in the Size S3 frame, rated for 30 kW at AC-2 duty on 400 V — the rating that governs motor switching for standard induction loads like pumps and conveyors in a control panel. It mounts via screw and snap-on onto 35 mm or 75 mm standard DIN rails, so it drops into a panel cut for the S3 footprint without adapters.
Key ratings and what they mean for fit
AC-2 at 400 V rated value of 30 kW is the load-bearing spec for wound-rotor or slip-ring motor applications — this is the duty cycle that governs the contactor's electrical life, not the higher AC-1 resistive rating. At AC-4 at 400 V the contactor handles 55 A, covering inching and plugging duty for high-stress motor reversals. Operating temperature range of -40 to +70 °C and pollution degree 3 mean it's suited for unheated industrial enclosures where conductive dust or humidity is present. Screw-type terminals for the main current circuit accept 2x (0.25... 2.5 mm²) solid or 2x (10... 50 mm²) stranded — the range covers both control wiring and power cable up to 50 mm² without lug adapters.
Lifecycle and compliance
Substance prohibitance date of 05/01/2012 indicates RoHS compliance per the EU directive.
Sourcing and RFQ
For a BOM line that needs the S3 frame with screw terminals and AC-2 motor rating, the 3RT1044-3KF44-0LA0 is the direct fit — the ratings above confirm it matches the spec without re-engineering the panel layout.