What It Is and What It Does
The Siemens 3RT1034-1BE40 is a SIRIUS power contactor in the S2 frame size, designed for switching motor loads and resistive loads in industrial control panels. It is rated for AC-3 duty at 18.5 kW at 400 V, meaning it handles the high inrush of squirrel-cage motors during starting and breaks the running current without issue. For AC-2 applications like slip-ring motors, it is rated at 15 kW at 400 V, and for AC-4 reversing or plugging duty, it carries 29 A at 400 V — the most demanding switching category, where the contactor makes and breaks stalled-rotor current.
Mounting and Integration
Mounts via screw or snap-on onto a 35 mm DIN rail per EN 50022, so it fits standard panel layouts without adapters. At 55 mm wide, 112 mm tall, and 130 mm deep, it leaves room for adjacent devices — side-by-side mounting is supported, which helps fill factor on a crowded DIN rail. The main circuit uses screw-type terminals; the control circuit accepts solid wire from 0.5 to 4 mm² and stranded up to 25 mm², covering typical panel wiring sizes.
Environmental and Compliance
Rated for pollution degree 3, so it is suited for industrial environments with conductive dust or condensation. Operating temperature spans -25 to +60 °C, with storage from -55 to +80 °C. The front face carries IP20 finger protection; the terminals are IP00, meaning the wiring zone is open and requires enclosure-level protection. The part is RoHS-compliant per the substance prohibition date of May 1, 2012, and carries a mechanical life of 10 million operations typical.