What it is and what it does
The Siemens 3RT1017-2BB41-ZX95 is a SIRIUS power contactor in frame size S00, designed for switching motor loads in industrial control panels. It carries a 24 V DC magnet coil with a 3.3 W holding power draw, so the control transformer or PSU needs to budget for that sustained load across the bank of contactors. Rated for 5.5 kW at 400 V in AC-3 duty (squirrel-cage motors), it also handles 5.5 kW at 400 V AC-2 (slip-ring motors) and 8.5 A at 400 V AC-4 (plugging/inching). The AC-4 rating is the one that governs for reversing or jogging applications — the AC-3 number alone doesn't cover that wear pattern. The auxiliary contact block carries a rated 10 A at 24 V, 6 A at 230 V, and derates to 0.3 A at 220 V DC — that DC rating is the limiting factor for switching small DC solenoids or indicator lamps in the same circuit.
Mounting and wiring
Mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 50022. The 45 mm width and 73 mm depth leave room for side-by-side ganging without extra spacing — useful when packing multiple contactors in a row on the rail. Main circuit wiring uses spring-loaded terminals accepting 2x (0.25 to 2.5 mm²) solid or stranded, or 2x (24 to 14 AWG). No screw torque to verify — just strip to 8 mm and push in. The IP20 finger-safe front and terminal cover means it's panel-safe without additional shrouding in a standard enclosure. Operates from -25 to +60 °C, with altitude limit of 2000 m and pollution degree 3 (conductive pollution, typical for industrial atmospheres). The 6 mm side clearance is for heat dissipation when mounted in free air; side-by-side mounting is allowed but check the temperature derating curve if the panel runs hot.
Protection and coordination
For Type 2 coordination (no damage to the contactor after a short circuit), the upstream fuse must be gL/gG 20 A. Type 1 coordination (contactor may need replacement after a fault) allows a 35 A gL/gG fuse. The mechanical life is 30 million operations, so it's rated for high-cycling applications like conveyor indexing or press feeders.