Rockwell Automation 150 MNL/SMC DIALOG+/APP-PROD GUIDE - Manual (Page 104)

4-22 Application Profiles for the SMC Dialog Plus Controller
Figure 4.21 Mixer with Dual Ramp Start
Problem: A mixer used an across-the-line starter to control motor
starting. The shock from the full voltage start frequently
broke the shear pin, causing the batch to be ruined as th
material solidified. Further, when the shear pin broke,
the vat required cleaning. Occasionally, the material
would begin to congeal before the mixer was started.
Full starting torque would then be required. Finally, a
connection to the PLC controlling many of the
applications in the facility was required.
Solution: The SMC Dialog Plus controller was installed and set for
a 13-second soft start, which smoothed the shock to the
impeller on start-up and kept the shear pin from breaking.
The Energy Saver feature reduced the voltage to the
motor when it was running lightly loaded. The SMC
Dialog Plus controller’s Dual Ramp Start feature allowed
for two starting ramps: the first for normal starting
conditions and the second with a higher starting torque
for the occasions when the product had begun to congeal.
The Dual Ramp Start feature saved valuable production
time, since the vat no longer required unloading once th
product started to congeal. The communications
capability of the SMC Dialog Plus controller allowed fo
connection to the PLC.
575 Volts
25 HP
Motor