What it is and where it fits
The Siemens SIRIUS 3RT1017-1AR01 is a size S00 power contactor — the smallest frame in the SIRIUS family, built for switching motor loads and resistive loads in control panels up to 5.5 kW. The S00 frame keeps the footprint tight at 45 mm wide, 57.5 mm tall, and 72 mm deep, so it packs into crowded DIN-rail enclosures without stealing space from the next device. It mounts via screw and snap-on onto 35 mm standard mounting rail per DIN EN 50022, and side-by-side mounting is permitted — no mandatory spacing gaps between contactors, which matters when you're stacking multiple contactors in a motor control centre row.
What the key ratings mean for your selection
The 24 VDC coil draws 10 A at rated value — that's the holding current, not the inrush. For a DC coil, the pick-up voltage is typically higher than the drop-out; this one holds in at 0.8 to 1.1 times rated voltage at 50 Hz and 0.85 to 1.1 at 60 Hz, so a saggy 24 VDC supply down to about 19.2 V still keeps it sealed. Below that, it drops out cleanly, which is the behaviour you want for a safety circuit. For motor duty, the AC-3 rating at 500 V is 5.5 kW — that's the standard induction motor switching capability. At 400 V AC-2 duty (slip-ring motors or high-inertia loads) it also delivers 5.5 kW. The AC-4 rating (plugging/reversing/inching) is 8.5 A at 400 V, which is about 3 kW on a 400 V motor — so if your application does frequent reversing, derate accordingly. The contactor is rated for pollution degree 3, meaning it's suitable for industrial environments where conductive pollution or dry non-conductive pollution that becomes conductive due to condensation can occur. Front protection is IP20 — finger-safe but not washdown-rated. Operating temperature spans -25 to +60 °C, which covers most indoor panel environments including unheated warehouses.
Coordination and wiring
For type 2 coordination (no damage to the contactor after a short circuit), Siemens specifies a gL/gG fuse of 20 A. For type 1 coordination (contactor may need replacement after a fault), the fuse can go up to 35 A gL/gG. That's the number your panel builder needs for the short-circuit protection device upstream. Main circuit terminals are screw-type, accepting 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or max 2x (0.75 to 4 mm²) solid or stranded conductors. AWG equivalents are 2x (20 to 16), 2x (18 to 14), and 1x 12. That covers most panel wiring up to 4 mm² without needing ferrule adapters. It carries one instantaneous auxiliary contact — that's the built-in mirror contact for feedback to the PLC or safety relay. If you need more auxiliary contacts, you add a side-mount block (SIRIUS 3RH series), which clips on without tools.
Lifecycle and sourcing reality
For a BOM line that needs this exact order code, the fit is confirmed by the S00 frame size, 24 VDC coil, and the screw terminal variant. The 3RT1017-1AR01 is the DC-coil version; the AC-coil sibling (3RT1017-1AP01) shares the same mechanical footprint and ratings but uses a different coil voltage — so they're not electrically interchangeable without changing the control circuit supply.