What it is and where it lands
The 3RT1023-1AN24: Mounts on 35 mm DIN rail per EN 50022 with a screw-and-snap-on mechanism, so it drops into any standard panel without a special bracket. The S0 frame keeps it to 45 mm wide, 85 mm tall, 140 mm deep — that's the same footprint as the rest of the SIRIUS S0 family, meaning a swap from a 3RT1023-1AL20 or similar S0 contactor is a direct mechanical fit.
What the key ratings mean for fit
The 8.5 A AC-4 rating is the one that matters for reversing or jogging duty — that's the worst-case current when the contactor makes and breaks locked-rotor current. For straight across-the-line starting (AC-3), the motor power ratings of 4.5 kW at 500 V and 5.5 kW at 690 V are the numbers to size against your motor nameplate. If you're coordinating fuses, the table calls for a 25 A gL/gG fuse for Type 2 coordination (no damage) and 63 A for Type 1 (damage allowed, replace the contactor). Operating temperature range is -25 to +60 °C, so it's fine inside a non-conditioned panel in most plant environments. Pollution degree 3 means it's rated for conductive pollution environments — think dust, light condensation, typical industrial panels.
Terminal and wiring detail
Main power terminals accept 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or up to 2x 4 mm² solid, with AWG equivalents at 2x (16 to 12), 2x (14 to 10), and 1x 8. That's enough for the main circuit wiring on a motor up to 5.5 kW. Auxiliary contacts are rated for 10 A at 24 V, 6 A at 230 V, 3 A at 400 V — enough for PLC-level control circuits.