What it is and what it does
The Siemens 3RT1316-2BG40 is a SIRIUS power contactor in frame size S00, designed for switching motor and resistive loads in industrial control panels. It carries four normally-open main contacts and is rated for a maximum operating current of 10 A under AC-12 duty, which covers resistive and solid-state loads. For motor switching under AC-2 at 400 V, it is rated for 4 kW, so it handles slip-ring motors or other loads where the contactor closes and opens under moderate inrush.
Key ratings and what they mean for fit
The AC-12 rating of 10 A is the thermal current the contactor can carry continuously in a resistive circuit — this is the figure to check against your heater or transformer load. For motor duty, the AC-2 rating at 400 V (4 kW) is the one that governs; it accounts for the moderate inrush of wound-rotor motors. The main contacts are also rated at 230 V for 6 A and at 400 V for 3 A, so if you are switching a 400 V resistive load, the 3 A figure is the limit per the datasheet. The auxiliary contact block is rated at 125 V with a current that varies by voltage: 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, and 0.3 A at 220 V. These are the switching capacities for the control circuit — the 24 V figure is what you use for a typical PLC output driving a relay, while the 220 V figure is for pilot-duty circuits in older panels. The coil is DC-operated, drawing 3.3 W for both closing and holding. That is a constant power draw regardless of the control voltage, so the thermal load on the enclosure is predictable. The operating voltage range factor is 0.85 to 1.1 times the rated value, meaning the coil will pick up reliably at 85% of nominal and will not overheat at 110%.
Mounting and integration
Mounts via screw or snap-on onto a 35 mm DIN rail per EN 50022. The dimensions are 45 mm wide, 60 mm high, and 72 mm deep, so it fits a standard 45 mm-wide slot in a panel layout. Side-by-side mounting is permitted, with a required clearance of 6 mm at the side for heat dissipation. The front face is rated IP20, which is finger-safe but not sealed against dust or moisture — keep it inside a cabinet. The main circuit terminals are spring-loaded, accepting solid or stranded conductors from 0.25 to 2.5 mm² (2x per terminal), or AWG 24 to 14. Finely stranded wire with ferrule is also supported from 0.25 to 1.5 mm². No screwdriver torque to set — just strip to 8 mm and push in. This speeds up panel wiring and reduces the chance of loose connections under vibration.
Environmental and coordination
Rated for pollution degree 3, so it is suitable for industrial environments with conductive dust or humidity. Operating temperature range is -25 to +60 °C, and the maximum operating altitude is 2 000 m without derating. For short-circuit protection, type of coordination 1 requires a gL/gG fuse of 35 A, while type 2 requires 20 A — the lower fuse rating limits let-through energy to protect the contactor from weld damage. Mechanical service life is rated at 30 million operations typical, which is the number of no-load cycles before mechanical wear. Electrical life depends on the switched current and voltage; for a given load, consult the derating curve in the full datasheet.