Rockwell Automation 150 MNL/SMC DIALOG+/APP-PROD GUIDE - Manual (Page 119)

Application Profiles for the SMC Dialog Plus Controller 4-37
Figure 4.36 Crane with Dual Ramp Start
Problem: An overhead crane required frequent jogging due to
adjustments in the traverse (horizontal) position. An
across-the-line starter was used, causing overshoot or
undershoot when trying to position the hook over a load.
When starting loaded, the crane required much more
starting torque. Contactors were frequently wearing out,
requiring replacement or repair. The application required
a device that could be programmed quickly, but whose
programming would not be readily accessible to the
operators.
Solution: The SMC Dialog Plus controller was installed. Reducing
the starting torque of the motor allowed the crane to be
positioned effectively, which resulted in fewer starts. The
SMC Dialog Plus controller helped reduce th
maintenance required and improve the productivity of the
crane. The ramp time was programmed through th
built-in programming keys on the front of the controller.
The built-in Dual Ramp Start feature allowed two ramp
times to be programmed, one for standard starting and
one for starting with an attached load. Password
protection prevented the operators from changing th
set up.
Traverse Motor
(Controlled by SMC Dialog Plus Controller)
480 Volts
10 H
Track
Load