What it is and what it does
The Siemens 3RT1044-1AP00 is a SIRIUS S3-frame power contactor rated for motor switching at 30 kW in AC-2 duty at 400 V, and 55 A in AC-4 duty at 400 V — the AC-4 figure governs reversing and plugging applications where the contactor makes and breaks stalled rotor current. It mounts via screw or snap-on onto 35 mm or 75 mm standard DIN rail, and side-by-side mounting is permitted, so panel density is not penalized. The main circuit uses screw-type terminals accepting solid conductors up to 2x 4 mm² and stranded up to 2x 50 mm².
Where it fits in the panel
At 70 mm wide by 146 mm high by 139 mm deep, the S3 frame fits standard motor-starter footprints; the IP20 front enclosure with IP00 terminal area means the contactor is protected against finger contact on the front but the lug area is live — plan for terminal shrouds or a cover/box terminal accessory if the panel has a higher touch-protection requirement. Pollution degree 3 rating suits it for industrial environments where conductive pollution or dry non-conductive pollution with occasional condensation occurs. Operating temperature range -25 to +60 °C covers most machine-tool and conveyor applications; storage range -55 to +80 °C is wider for warehouse cycling.
Switching performance and coil data
Arcing time is 10 to 15 ms, with total make/break time at AC supply 10 to 19 ms — fast enough for most PLC-controlled sequences without desat detection. Coil operates at 50 Hz with a voltage tolerance factor of 0.8 to 1.1 times rated; the 24 V DC coil draws 10 A inrush, dropping to lower hold-in current. Mechanical life is typical 10 million operations; maximum switching rates are 1000 cycles/hour at AC-1 and AC-3, 400 at AC-2, and 300 at AC-4 — the AC-4 rate is the limiting factor for frequent reversing duty.
Lifecycle and compliance
RoHS compliance date is 05/01/2012, covering the EU RoHS substance prohibitions. The part carries no UL/CSA/CE mark in the available spec record — verify with the factory or a local Siemens representative if your panel requires third-party certification.