Rockwell Automation 20G PowerFlex 750-Series AC Drives - Manual (Page 96)

96 Rockwell Automation Publication 750-RM002B-EN-P - September 2013
Chapter 1 Drive Configuration
Stop Modes Stop Mode A/B can be configured as a method of stopping the drive when a stop
command is given. A normal stop command and the run input changing from
true to false results in a normal stop command. However, when using
TorqueProve, P1100 [Trq Prove Cfg] with Bit 0 enabled, [Stop Mode A/B] must
be set to 1 “Ramp.”
P392 [Stop Dwell Time] can also be used with a stop command. This can be used
to set an adjustable time between detecting zero speed and turning off the drive
output.
The PowerFlex 750 series offers several methods for stopping a load. The stop
method or mode is defined by parameters 370/371 [Stop Mode A/B] These
modes include the following:
• Coast
• Ramp
• Ramp to Hold
• DC Brake
• DC Brake Auto Off
• Current Limit
• Fast Brake
Additionally, P388 [Flux Braking In] can be selected separately (not part of the
Stop mode selection) to provide additional braking during a Stop command or
when reducing the speed command. For Stop commands, this provides additional
braking power during “Ramp” or “Ramp to Hold” selections only. If “Fast Brake”
or “DC Brake” is used, “Flux Braking” is active only during speed changes (if
enabled).
A “Ramp” selection always provides the fastest stopping time if a method to
dissipate the required energy from the DC bus is provided (that is Dynamic
Braking resistor, regenerative brake, and so forth.). The PowerFlex Dynamic
Braking Selection Guide presented in Appendix A of the Reference Manual,
explains Dynamic Braking in detail.
The alternative braking methods to external hardware brake requirements, can be
enabled if the stopping time is not as restrictive. Each of these methods dissipates
energy in the motor (use care to avoid motor overheating).