The 3RT2028-2AG20: The AC-3 switching frequency is rated at 750 operations per hour maximum. That's the standard motor-switching duty cycle — running a pump or conveyor at that rate is fine, but if you're jogging or inching a load, you'll need to stay under the AC-4 limit of 250 ops/h to avoid overheating the contacts. That's the contactor body itself — the electrical life will be lower depending on the load and switching frequency, but the mechanical endurance means the frame and armature aren't the weak link in a high-cycle application. That's the inrush to pull the armature in; holding current will be lower. Make sure your 24 VDC supply can deliver that peak without droop, especially if you're switching multiple contactors simultaneously.
That's tighter than some contactors, so you can pack them in a bit more on the rail. That helps when you're fitting it into an odd-angle sub-panel or a tight enclosure corner.
Spring-type terminals on the coil — no screw tightening needed, just push in the ferrule. Main contacts accept solid or stranded wire from 1 to 10 mm², and fine-stranded (2x 0.5 to 2.5 mm²). That covers most motor leads up to about 4 kW at 400 V. Torque for main contacts is 18 to 8 Nm — that's a wide range, so check the specific terminal marking before tightening.
The storage range is wide enough for long-term spares in a cold storeroom.