SIRIUS S00 power contactor, 24 VDC coil, spring-loaded terminals
The Siemens 3RT1017-2MB41-0KT0 is a SIRIUS Size S00 power contactor with a 24 VDC magnet coil, rated for motor switching up to 5.5 kW at 690 V AC-3. It snaps onto a 35 mm DIN rail per DIN EN 50022 and uses spring-loaded terminals on the main circuit — no screwdriver needed for the power wires, which saves time on repetitive panel builds. The coil draws 1.4 W holding power, so it runs cool in a crowded enclosure.
Ratings and what they mean for your panel
The AC-3 motor rating of 5.5 kW at 690 V tells you this contactor handles a standard 3-phase induction motor up to that load. The AC-4 rating of 8.5 A at 400 V covers reversing or inching duty where the contactor makes and breaks stalled-rotor current — that's the number to watch if you're plugging or jogging a conveyor. For resistive loads (AC-1), the maximum operating current is 10 A at 24 V. The mechanical life of 30 million operations means the coil and armature will outlast most panel revisions. Pollution degree 3 means it's rated for industrial environments with conductive dust or occasional condensation — typical for an unsealed panel in a factory. The IP20 front and terminal protection keeps fingers out but doesn't tolerate washdown; mount it inside a cabinet with at least IP54 if the area is wet. Side-by-side mounting is allowed without derating, so you can pack S00 contactors on 45 mm centres. The 6 mm side clearance to adjacent components is the minimum gap for heat dissipation when not mounting flush.
Wiring and termination
Spring-loaded terminals on the main circuit accept 2x (0.25 to 2.5 mm²) solid or stranded, or 2x (24 to 14 AWG). No ferrules required for stranded if the strands are twisted — the cage grabs them directly. The coil terminals are also spring-loaded; strip 8 mm and push in. For type 2 coordination (no weld-sticking under fault), use a 20 A gL/gG fuse upstream; for type 1 coordination (allow contactor replacement after fault), a 35 A fuse is permitted.