The 3RT7027-1AG05: The AC-3 rated voltage maxes out at 690 V, with corresponding breaking currents of 6 A at 230 V, 3 A at 400 V, and 1 A at 690 V. That covers most three-phase motor circuits up to about 2.2 kW at 400 V — a common size for small conveyors, pumps, or fans. The contactor is rated for 800 switching cycles per hour under AC-3 duty, dropping to 250 cycles/h under AC-4 (plugging / inching). If your application calls for frequent jogging, that AC-4 limit is the one to watch. Both the front and terminal areas carry an IP20 rating, meaning finger-safe terminals — fine for enclosed panels, but not for washdown environments. The coil draws 0.82 W on closing and holds at 0.24 W DC, so the control transformer can be sized modestly. Auxiliary contacts are rated for PLC-level signals — the spec calls out acceptability for 17 V, 5 mA, so you can wire them directly to a digital input without worrying about contact wetting.
Shock resistance is 12.5g at 5 ms and 7.8g at 10 ms, which covers most industrial panel applications short of heavy stamping presses.
Fuse coordination and compliance
The insulation voltage rating is 690 V, matching the AC-3 max.