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. 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.
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. 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
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.