What it is and where it fits
The Siemens 3RT1024-1AP00-ZW96 is a SIRIUS power contactor in the S0 frame size, with three normally-open main contacts and a 230 V AC 50 Hz coil. It mounts via screw or snap-on to a 35 mm DIN rail per EN 50022, so it drops straight into a standard panel without adapter plates. At 45 mm wide and 85 mm tall, it fits the S0 footprint — a common size for motor loads up to 7.5 kW at 400 V AC. The 91 mm depth leaves room for wiring in a 200 mm deep enclosure.
Key ratings and what they mean for your load
Rated for AC-2 duty at 400 V at 5.5 kW and AC-4 at 400 V at 12.5 A, this contactor handles reversing or plugging applications where the motor sees frequent starts and stops — AC-4 covers the severe switching duty that wears contacts faster than a simple on-off load. At 690 V it still delivers 7.5 kW, so it works on 400 V and 690 V systems without derating the motor power. The coil holds at 0.8 to 1.1 times rated voltage at 50 Hz — meaning it pulls in reliably even if the line dips to 184 V AC. The auxiliary contact block (not included) carries 10 A at 24 V AC, 6 A at 230 V AC, and 3 A at 400 V AC — enough for a PLC input or a pilot lamp. For DC switching, it handles 10 A at 24 V, 2 A at 60 V, and 0.3 A at 220 V.
Terminal specs and wiring
Main circuit terminals are screw-type, accepting 2x (1 to 2.5 mm²) solid or 2x (2.5 to 6 mm²) stranded, with a maximum of 2x 10 mm². The auxiliary terminals take 2x (0.5 to 1.5 mm²) solid or 2x (0.75 to 2.5 mm²) stranded, max 2x 4 mm². That covers most panel wiring up to 10 AWG for the main power and 14 AWG for control circuits. For Type 2 coordination (no weld) the required fuse is gL/gG 25 A; for Type 1 coordination (allow weld, replace) it's 63 A. That matters when you're sizing the branch circuit protection — pick the fuse class based on whether you can tolerate a welded contactor in a fault.
Environmental and mounting
Operating temperature range is -25 to +60 °C, and the contactor is rated for pollution degree 3 — the typical industrial environment with conductive dust or occasional condensation. The front is IP20, the terminals are IP00 (finger-safe only with the enclosure door closed). Side-by-side mounting is allowed at 6 mm spacing, so you can pack multiple contactors on the same DIN rail without derating — useful when building a motor control center in a tight panel. Maximum operating altitude is 2,000 m — above that, air density drops and you'd need to derate the dielectric and thermal performance. Most plants are below that, but check if your site is in the mountains.