What it is and where it lands
The Siemens SIRIUS 3RT1017-1AK61-ZX95 is a power contactor in the S00 frame size, rated for switching three-phase motor loads up to 5.5 kW at 400 V AC-3. It carries one normally-open auxiliary contact and terminates with screw-type terminals on both main and auxiliary circuits. The 45 mm wide body snaps onto a 35 mm DIN rail per EN 50022. The S00 frame keeps this a compact panel fit — 45 mm wide, 57.5 mm high, 72 mm deep. Side-by-side mounting is permitted with no derating gap, which helps fill factor in dense control cabinets. The front face carries IP20 touch protection; the terminals are also IP20.
What the ratings mean for the buyer
The headline motor rating is 5.5 kW at 400 V AC-3. AC-3 is the standard duty for squirrel-cage induction motors — starting and disconnecting under load. That 5.5 kW figure governs the real-world motor size this contactor can handle on a 400 V line. For higher-stress switching (plugging, inching), the AC-4 rating is 8.5 A at 400 V, which is the figure to check if the load sees reversing or jogging cycles. The auxiliary contact is rated at 10 A at 24 V, 6 A at 230 V, and 3 A at 400 V — these are AC-12 resistive-load values. For inductive DC loads, the same contact breaks 2 A at 60 V, 1 A at 110 V, and 0.3 A at 220 V. That DC curve matters if you're switching a PLC input or a holding brake directly. Short-circuit coordination is specified with gL/gG fuses: 20 A for Type 2 coordination (no damage to the contactor) and 35 A for Type 1 (contactor may need replacement after fault). The wire range for main terminals accepts 2x (0.5...1.5 mm²), 2x (0.75...2.5 mm²), or max 2x (0.75...4 mm²) — or AWG equivalents 2x (20...16), 2x (18...14), and 1x 12.
Integration and mounting notes
Mounting is screw or snap-on onto a 35 mm DIN rail per EN 50022. The 45 mm width matches the standard S00 footprint, so it occupies one 45 mm slot in a rail-mounted assembly. Ambient operating temperature range is -25 to +60 °C, and the maximum operating altitude is 2 000 m. Pollution degree 3 means it is suitable for industrial environments with conductive pollution — typical for control panels near machinery. The coil operating range is 0.85...1.1 x rated voltage at 50 Hz, and 0.8...1.1 at 60 Hz. At 50 Hz the rated control supply voltage is 110 V; at 60 Hz it is 120 V. The mechanical life is typical 30 million operations.