Duty-cycle limits and mechanical life
The 3RT2028-1AM20: Maximum switching frequency depends on the duty class: 1000 operations per hour in AC-1 resistive load, 750/h in AC-3 motor-switching duty, and 250/h in AC-4 inching/plugging service — the AC-4 figure is the one to budget for high-cycling applications.
Mounting position flexibility
Minimum clearances: 10 mm upwards, downwards, and forwards; 6 mm at the side — plan the gland plate and busbar clearance accordingly.
