What It Is and Where It Fits
The Siemens 3RT1316-2BD40 is a SIRIUS power contactor in the compact S00 frame size, designed for switching motor loads and resistive loads in control panels. It mounts via screw or snap-on onto a 35 mm DIN rail per EN 50022, making it a direct fit for standard industrial enclosures. Its 4 normally open main contacts and spring-loaded terminals (accepting 2x 0.25–2.5 mm² solid or stranded) allow for quick wiring without screwdriver torque checks — a time-saver on repetitive panel builds.
Key Ratings and What They Mean for Your Load
Rated 4 kW at AC-2 duty on 400 V, this contactor handles wound-rotor motors and slip-ring applications where moderate inrush and frequent switching are expected. That 4 kW figure is the real-world motor rating — not the resistive AC-1 number — so it governs the motor nameplate you can connect. For coordination, Type 1 requires a 35 A gL/gG fuse upstream; Type 2 needs a 20 A gL/gG fuse. This affects your short-circuit protection scheme — Type 2 limits contactor damage after a fault, while Type 1 allows replacement after a fault. Choose based on your maintenance philosophy. The coil holds at 42 V rated value with a closing and holding power of 3.3 W DC, meaning a standard 24 VDC supply can drive it through a PLC output, but verify the pull-in voltage (0.85 x rated) and drop-out (1.1 x rated) margins against your control voltage stability.
Installation and Environment
Side-by-side mounting is permitted without derating, saving rail space in dense panels. The IP20 finger-safe protection on the front and terminals means it's suitable for enclosed cabinets where personnel access is controlled. Operates from -25 °C to +60 °C, with a maximum altitude of 2,000 m and pollution degree 3.