Rockwell Automation 150 MNL/SMC DIALOG+/APP-PROD GUIDE - Manual (Page 100)

4-18 Application Profiles for the SMC Dialog Plus Controller
Figure 4.17 Hammermill with Current Limit Start
Problem: A hammermill with a high inertia load required a reduced
voltage start because of power company restrictions.
High torque on start-up was causing belt wear. Panel
space was very limited. Traditional reduced voltage
starters would not fit in the available space.
Solution: The SMC Dialog Plus controller was installed and set for
a 23-second, 425% current limit start, which met the
power company’s requirement for the reduced voltage
start. The belt life was extended since the starting torque
was reduced. A current limit start was selected to quickly
break away the high inertia load and still provide a
reduced voltage start. The Energy Saver feature was used
when the mill was running lightly loaded. The compact
size of the SMC Dialog Plus controller, along with th
built-in overload feature, enabled the controller to fit into
the available panel space.
480 Volts
250 HP
Belts
Motor
Feed
Hammer