Rockwell Automation 150 MNL/SMC DIALOG+/APP-PROD GUIDE User Manual
Page 91
Application Profiles for the SMC Dialog Plus Controller
4-9
Figure 4.8 Bandsaw with Soft Start and SMB Smart Motor Braking Option
Problem: A bandsaw application required a reduced voltage start
because of power company restrictions. A brake package
was required to reduce the stopping time of the saw.
Previously, an autotransformer had been used to start the
saw. The saw was stopped by sawing down. Sawing
down is accomplished by running logs through the saw
after the motor has been de-energized, which results in
large amount of scrap lumber. Other stopping methods
using dedicated braking devices were investigated but
were unacceptable because of overly complex
installation. Additionally, other stopping methods
required panel space for the brake module, brak
contactors and timers, and they offered no zero speed
detection.
Solution: The SMC Dialog Plus controller with the SMB Smart
Motor Braking option was installed. It provided the
reduced voltage start needed to meet the power company
restrictions. The SMB Smart Motor Braking option did
not require additional panel space or DC braking
contactors. The starting and stopping control was
furnished in a single modular design, providing ease of
installation.
Saw Blade
Motor
High Inertia Wheels
Carriage
Log
480 Volts
250 HP