What it is and what it does
The Siemens 3RT1017-1AT61 is a SIRIUS power contactor in frame size S00, designed for switching motor loads and resistive loads in industrial control panels. It carries three normally-open main contacts and no normally-closed main contacts, so it is a straight three-pole make device — typical for three-phase motor circuits where you only need to close the power path. Rated for AC-2 duty at 5.5 kW on 400 V, it handles slip-ring motor starting and braking. For AC-4 duty (plugging, inching) it is rated 8.5 A at 400 V — that is the current that governs the contactor's life under frequent reversals or jogging, not the AC-2 figure. The auxiliary contact block (integrated) switches 10 A at 24 V, 6 A at 230 V, and 0.3 A at 220 V DC — the DC ratings are the ones to watch if you are switching a PLC output or a DC brake coil; the inductive DC load will arc longer than the AC equivalent.
Mounting and integration
Mounts via screw or snap-on onto a 35 mm DIN rail per EN 50022. The 45 mm width and 57.5 mm height keep it compact for a three-pole S00 contactor. Side-by-side mounting is permitted, so you can gang multiple contactors without spacing — useful for a motor control centre row. Front face carries IP20 finger protection; the terminals are also IP20. Pollution degree 3 means it is rated for industrial environments with conductive pollution — standard for an unsealed panel-mounted device.
Key ratings at a glance
Main contact ratings: 5.5 kW at 400 V AC-2, 5.5 kW at 690 V AC-2, 8.5 A at 400 V AC-4. Auxiliary contact: 10 A at 24 V AC-12, 6 A at 230 V, 2 A at 60 V DC, 0.3 A at 220 V DC. Operating temperature: -25 to +60 °C. Maximum operating altitude: 2 000 m. Terminal capacity: screw-type terminals accepting 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or max 2x (0.75 to 4 mm²) solid/stranded, plus 1x 12 AWG. Short-circuit protection: fuse gL/gG 20 A for type 2 coordination, 35 A for type 1.