The Siemens 3RT7025-1AL20 is a 3-pole S0-frame contactor from the SIRIUS family, rated for AC-3 switching up to 690 V.
The AC-3 rating at 690 V maximum means it can switch three-phase motor loads at that line voltage — relevant for 690 V industrial networks common in mining, marine, and heavy machinery. The 3-pole, 3-NO main contact arrangement is the standard for three-phase motor starting; no NC contacts on the mains side. IP20 on the front and at the terminals means finger-safe touch protection — no special sealing against dust or moisture, so this is a panel-inside part, not for washdown or outdoor duty. Pollution degree 3 confirms it's rated for conductive environments inside an enclosure. That saves a relay interface on the control side. Coil draw is 0.72 W on pickup, dropping to 0.24 W sealed — low enough that a 24 VDC power supply driving a bank of these won't sag on inrush. The AC control supply voltage type means the coil is designed for AC line, not DC; verify your control voltage matches before wiring.
Integration notes
That covers most panel layouts without derating, but side-by-side mounting is allowed if you need dense packing. Screw terminals on both main and control circuits accept 2x 0.5–2.5 mm² solid or stranded, or 2x 0.5–1.5 mm² with ferrules. Strip length and torque spec follow standard Siemens SIRIUS practice — no special tooling needed. For type 2 coordination (no-weld fault protection), the required upstream fuse is 25 A gL/gG; for type 1 (allow-weld), 63 A gL/gG. That's the fuse size to spec on the line side if you're coordinating with a motor starter or soft starter.