SIRIUS S2 Power Contactor for Motor Loads
The Siemens 3RT2038-1AH00 is a SIRIUS-brand power contactor in the S2 frame size, designed for switching three-phase motor loads in industrial control panels. Its headline rating is 65 A at 480 V in AC-3 duty — the motor-switching category per IEC 60947-4-1 — meaning it handles induction motors up to roughly 50 hp at that voltage without welding the main contacts during starting inrush. The coil is 24 VDC, terminated at screw-type terminals, and the contactor carries an auxiliary switch block (18...1 configuration) for status feedback to the PLC or safety circuit. Mechanical life is rated at 10 million operations typical, with electrical endurance varying by duty: 700 cycles/hour at AC-1 (resistive), 500 at AC-3 (motor start/run), and 150 at AC-4 (plugging/reversing). The 3RT2038-1AH00 mounts on 35 mm DIN rail per DIN EN 60715 via screw and snap-on fastening, or directly with screws. The S2 frame footprint is 55 mm wide, 114 mm tall, and 130 mm deep — a compact envelope for a 65 A motor-rated contactor that fits standard 600 mm deep enclosures with room for wiring gutters.
Integration into the Panel
Mount the contactor on 35 mm DIN rail with the snap-on mechanism; the screw fastening option is available if vibration is a concern (e.g., on a crane panel or near a large motor starter). The mounting position allows ±180° rotation on a vertical surface and ±22.5° tilt forward/backward — useful when the contactor sits in a tight sub-panel or on a swing frame. Clearance distances: 10 mm upward, 10 mm forward, 10 mm downward, and 6 mm at the sides. These are the minimum air gaps to adjacent metalwork or other devices for heat dissipation and arc containment. The arcing time is 10 to 20 ms, and the switching time (AC) is 10 to 18 ms — standard for a contactor of this frame size. Wire termination: the main power terminals accept 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) solid or stranded copper — sized for the control wiring and auxiliary contacts, not the main power lugs (which are typically larger on an S2 frame). The coil terminals are screw-type, compatible with ferruled stranded wire for reliable connection in high-vibration environments.
Environmental Range
Operating temperature: -25 to +60 °C. Storage temperature: -55 to +80 °C. The storage range exceeds the operating range because it governs handling and warehousing, not running. The contactor is rated for indoor use in a standard industrial enclosure; no IP rating is listed on this record, so it requires panel protection from dust and moisture.