What this contactor is and what it does
The Siemens SIRIUS 3RT1317-1AN20 is a size S00 power contactor with four normally-open main poles, rated for switching motor loads up to 5.5 kW at 400 V under AC-2 and AC-3 duty. That 5.5 kW figure at 400 V is the motor-rating spec you match to the nameplate — it tells you the contactor can handle the inrush and break the running current of a motor in that power class. The 4-pole configuration means it can switch a three-phase motor plus a neutral or a second load leg, or be used for resistive loads where you need four switched lines. The 24 VDC coil is what pulls the contacts in; the holding voltage range is 0.8 to 1.1 times rated at 50 Hz and 0.85 to 1.1 at 60 Hz, so it stays sealed across a typical control supply sag. The auxiliary contact ratings — 10 A at 24 V, 2 A at 60 V, 1 A at 110 V, 0.3 A at 220 V — cover the PLC output or relay that drives it, and the contactor itself carries no built-in auxiliary contacts (shows zero NC on main contacts), so plan for an external auxiliary block if you need feedback.
Mounting and integration into the panel
This contactor mounts via screw or snap-on onto a 35 mm DIN rail per DIN EN 50022. The footprint is 45 mm wide, 57.5 mm tall, and 72 mm deep — that 45 mm width is the key dimension for rail spacing and enclosure fill. Side-by-side mounting is allowed with a 6 mm gap to the side, so you can gang multiple contactors on the same rail without derating, provided you respect the ambient temperature range of -25 to +60 °C. The screw-type terminals on the main current circuit accept solid and stranded conductors: 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), and max 2x (0.75 to 4 mm²). For AWG, that's 2x (20 to 16), 2x (18 to 14), and 1x 12. The IP20 rating on the front and terminals means finger-safe for the panel builder, but not protected against dust ingress — this is a standard control-panel part, not for open-air or washdown zones.
Coordination and protection requirements
For Type 2 coordination (no damage to the contactor under short circuit), the required upstream fuse is gL/gG 20 A. For Type 1 coordination (contactor may need replacement after a fault), the fuse rating is gL/gG 35 A. The degree of pollution 3 means it's rated for conductive pollution environments typical in industrial enclosures — no additional conformal coating needed for most panel conditions. Mechanical endurance is rated at 30 million operations — that's the life of the mechanism before wear, not the electrical life under load. Electrical life depends on the switching current and duty cycle; for motor switching at 5.5 kW, expect significantly fewer operations, but the mechanical floor tells you the actuator won't be the first thing to fatigue.