The Siemens SIRIUS 3RT1316-2AF00 is a Size S00 power contactor with four normally-open main contacts, rated for 4 kW at AC-2 duty on a 400 V supply. The 24 VDC coil pulls in reliably across the 0.8–1.1 x Us range at 50/60 Hz. Spring-loaded terminals accept 2x (0.25–2.5 mm²) solid or stranded — no ring lugs needed, which shaves a few minutes per termination on a panel build. Mounts via screw or snap-on onto 35 mm DIN rail per EN 50022. The 45 mm width and 72 mm depth fit standard S00 slot spacing; side-by-side mounting is allowed with no derating gap, so you can pack four or five across a 230 mm rail section.
What the ratings mean for fit
The AC-2 rating at 400 V (4 kW) covers slip-ring motor starting and reversing — the kind of duty you see on crane hoists or conveyor reversers. AC-12 at 10 A covers resistive loads like heater banks or control transformers. For motor switching on standard squirrel-cage induction motors, you would typically size by the AC-3 rating; this contactor's AC-3 capability is not listed in the spec set, so verify against your motor FLA. Coil operates at 24 VDC with a tolerance band of 0.8–1.1 x Us at 50 Hz and 0.85–1.1 x Us at 60 Hz. That means at 50 Hz the coil holds from about 19.2 V to 26.4 V; at 60 Hz the lower end tightens to 20.4 V. If your control supply is marginal or long cable runs cause voltage drop, factor the 60 Hz band. IP20 on the front and terminals — protected against finger contact but not moisture. Suitable for enclosed panels; not for washdown or outdoor exposure without an additional enclosure. Pollution degree 3 means it tolerates conductive dust and occasional condensation, typical of industrial control rooms.
Mounting and wiring integration
Snap onto 35 mm DIN rail — no tools needed for the rail mount. The spring terminals accept 0.25–2.5 mm² (AWG 24–14) solid or ferruled stranded, two conductors per clamp. Strip length around 8–10 mm; push the screwdriver into the square opening, insert the wire, release. No torque driver required, which speeds up panel wiring. Type 1 coordination calls for a 35 A gL/gG fuse upstream; Type 2 coordination requires 20 A. If your panel has a 20 A branch circuit, the Type 2 fuse protects the contactor under a short-circuit condition without damage. For a 35 A circuit, the contactor may need replacement after a fault.