The Siemens 3RT1023-1AG24-ZX95 is a SIRIUS S0-frame power contactor with a 24 VDC coil, rated for 10 A in AC-12 duty.
The AC-12 rating of 10 A covers resistive loads like heaters and incandescent lighting. For motor duty, the AC-2 rating at 400 V is 4 kW, and AC-4 at 400 V is 8.5 A — that's the reversing/plugging current, so if your application does frequent inching or reversing, this is the number to watch, not the AC-12 figure. Coil draws at 24 VDC are not listed here, but the auxiliary contact ratings are: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, 0.3 A at 220 VDC. For DC switching, the 220 VDC 0.3 A rating is the inductive load limit — don't expect it to break a 2 A DC motor brake circuit. The S0 frame (45 mm wide, 85 mm tall, 140 mm deep) fits standard 35 mm DIN rail. Side-by-side mounting is permitted with 6 mm spacing between units. Screw terminals accept 2x (0.5...1.5 mm²) solid, 2x (0.75...2.5 mm²), max 2x (0.75...4 mm²). Main circuit terminals take up to 2x 10 mm² stranded. The terminal enclosure is IP00 (open), while the front is IP20 — finger-safe once installed in a panel.
For a panel builder, Type 2 is the safer spec — the 25 A fuse limit is what you'd put on the BOM.
Operating conditions
Rated for -25 to +60 °C ambient during operation, with a maximum installation altitude of 2,000 m. The coil hold-in voltage range is 0.8...1.1 x Us at 50 Hz and 0.85...1.1 x Us at 60 Hz — so at 24 VDC nominal, dropout is below about 19.2 V.