What this part is and what it does
The Siemens 3RT1017-1BW42 is a SIRIUS power contactor in frame size S00, designed for switching motor loads and resistive loads in industrial control panels. It mounts on a 35 mm DIN rail per DIN EN 50022 using either screw or snap-on fixing, and occupies 45 mm of panel width. The front and terminal area carry an IP20 rating, meaning it is protected against finger contact but not against moisture — it belongs inside an enclosure, not exposed to washdown. This contactor is rated for motor switching at 5.5 kW in AC-3 duty at 400 V and also at 690 V, making it suitable for standard 400 V three-phase induction motors up to that power. The AC-2 rating at 400 V is also 5.5 kW, covering wound-rotor motor applications. For high-inrush or plugging duty, the AC-4 rating at 400 V is 8.5 A, which is the figure to watch for reversing or inching cycles.
Key ratings and what they mean for your panel
The AC-3 rating of 5.5 kW at 400 V is the headline motor-switching capability — it handles the starting inrush and breaking of a running motor within that power band. The AC-4 rating of 8.5 A at 400 V is the more demanding duty cycle: it covers starting, plugging, and inching where the contactor makes and breaks stalled-rotor current. If your application involves frequent reversing or jogging, the AC-4 figure governs contact life, not the AC-3 number. Short-circuit coordination is specified: for Type 2 coordination, use a gL/gG fuse rated 20 A; for Type 1, a 35 A fuse is required. This means the contactor will withstand a fault up to the prospective short-circuit current without welding its contacts (Type 2) or with acceptable contact damage (Type 1), provided the listed fuse is upstream. The magnet coil draws 3.3 W DC both for closing and holding — a single-wattage coil, not a two-stage economized design. This is a constant DC load on the control supply, so factor it into your 24 VDC power budget if you are ganging several contactors. Auxiliary contact ratings are given across the voltage range: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, and 0.3 A at 220 V DC. These are the switching capacities for the built-in auxiliary contacts — use the DC rating for pilot duty on PLC inputs or relay coils. Mechanical life is rated at 30 million operating cycles typical. This is the mechanical endurance without electrical load — actual electrical life will be lower and depends on the switched current and duty category.
Mounting and integration details
Mounts on 35 mm DIN rail per DIN EN 50022, either by screwing or snapping on. Side-by-side mounting is permitted with zero side clearance — the 6 mm spacing to adjacent devices is a minimum for heat dissipation, not a mandatory gap. The S00 frame is 45 mm wide, 57.5 mm tall, and 72 mm deep, so it fits standard 80 mm deep enclosures. 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 wire. AWG equivalents are 2x (20 to 16), 2x (18 to 14), and 1x 12. The dual-wire entry is useful for daisy-chaining power through the contactor without a separate terminal block. Operating temperature range is -25 to +60 °C, with a maximum altitude of 2 000 m without derating. Pollution degree 3 means it is suitable for industrial environments with conductive pollution — standard for enclosed panel gear.
Lifecycle and sourcing reality
Compliance documentation is standard for Siemens industrial controls: the part carries CE marking for the European market and is designed to meet IEC/EN 60947-4-1 for contactors and motor-starters. UL and CSA listings are typical for this series, though the specific approvals for this order code should be confirmed on the nameplate or via the manufacturer's declaration of conformity.