Rockwell Automation 150 MNL/SMC DIALOG+/APP-PROD GUIDE - Manual (Page 35)

2-16 SMC-2 Smart Motor Controller
Applications (cont.)
Figure 2.18 Grinder with Soft Start
Problem: Due to the high starting torque developed from starting
the motor across-the-line, the gears driving a grinding
wheel were frequently damaged. This resulted in
unscheduled downtime for repair. This application
required a rugged device because vibration at the control
panel was a problem.
Solution: The SMC-2 controller was installed and set for a
20-second acceleration time. This reduced the starting
torque and the downtime for repairs on the grinder. In
addition, the benefit of the Energy Saver was realized
when the motor was running lightly loaded. The SMC-2
controller meets the same shock and vibration
requirements as electromechanical devices, therefore it
met the durability requirements.
575 Volts
20 HP
Motor Gearbox
Grinding
Wheel