The Siemens 3RT7025-1AF05 is a Size S0 3-pole contactor for switching motor loads in control panels. It carries a 6 A rated operational current at 230 V in AC-3 duty, so it handles small three-phase motors up to roughly 2.2 kW at 400 V. The AC coil is rated 110 V at 50 Hz and draws 0.24 W holding power — a standard control-voltage pick for European panels.
The 55 mm width and 91 mm depth mean it fits a standard S0 footprint — side-by-side mounting is allowed, so you can gang several on the same rail without derating. Mounting position is flexible: ±180° rotation on a vertical surface, and can be tilted forward or backward by ±22.5°.
Switching performance and protection
Rated insulation voltage is 690 V, with surge voltage resistance of 6 kV — enough for 400 V line-to-line systems with a margin. AC-3 maximum switching frequency is 800 operations per hour; AC-4 (plugging/reversing) is 250 per hour. For short-circuit protection, type 1 coordination requires a 63 A gL/gG fuse; type 2 coordination (no damage to the contactor) needs a 25 A gL/gG fuse. Auxiliary contacts are rated for PLC-level signals — 17 V, 5 mA — so they switch directly into a digital input without a relay interface.