What it is and where it fits
The Siemens SIRIUS 3RT1024-1AP00-ZW97 is a power contactor in the S0 frame size, built for switching three-phase motor loads and resistive loads in industrial control panels. It mounts via screw or snap-on onto a 35 mm DIN rail per EN 50022, so it drops straight into a standard panel layout without adapter plates. The 45 mm width and 85 mm height keep the footprint tight for multi-contactor assemblies.
What the ratings mean for the buyer
Three normally-open main contacts handle the power circuit with no normally-closed auxiliary — pure make duty for motor starting or resistive loads. The AC-4 rating of 12.5 A at 400 V tells you it can handle the toughest inching and plugging duty cycles where the contactor makes and breaks full locked-rotor current. For AC-2 duty at 400 V it's rated for 5.5 kW, which covers slip-ring motor applications. The operating temperature range of -25 to +60 °C means it lives in unheated enclosures and hot panel environments without derating headaches. IP20 on the front face keeps fingers out; the terminals themselves are IP00, so the panel builder needs to guard live connections per code.
Panel integration and wiring
Screw-type terminals on the main current circuit accept solid and stranded conductors: 2x (0.5 to 1.5 mm²), 2x (0.75 to 2.5 mm²), or a single run up to 2x 4 mm². For AWG, that's 2x (16 to 12) and 2x (14 to 10). The depth of 91 mm means it projects about three and a half inches into the enclosure — check your gland plate clearance if you're packing multiple rows. Side-by-side mounting is allowed with a 6 mm gap to the side for heat dissipation, so you can gang them on the rail without oversizing the cabinet.