The Siemens 3RT1275-6AS36 is a SIRIUS vacuum contactor in size S12, designed for switching motor loads in industrial control panels where high switching frequency and low contact erosion are required. The vacuum arc-quenching chamber eliminates open arcing, making it suitable for frequent AC-3 duty at up to 750 operating cycles per hour (cite:). Coil voltage is rated 500-550 V AC (cite:).
Ratings and what they mean for fit
The main circuit accepts stranded conductors from 70 to 240 mm² (cite:), which covers typical motor feeds for contactors of this frame size — expect to terminate with compression lugs. The auxiliary contact block is screw-type (cite:), accepting 2x (0.5–1.5 mm²) solid or 2x (0.75–2.5 mm²) stranded (cite:). Mechanical endurance is rated at 10 million operations (cite:), which translates to years of service in high-cycle applications like conveyor or pump control. Mounting position allows ±22.5° rotation on a vertical surface and can be tilted forward/backward by the same angle, or mounted standing on a horizontal surface (cite:).
Lifecycle and sourcing reality
This part is listed in the current lifecycle stage (cite:). It is available to source through independent distribution channels; availability and current pricing are confirmed at quote time against an RFQ. No official successor has been published, so the 3RT1275-6AS36 remains the correct order code for new BOM lines and replacements.