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Rockwell Automation Publication 35-UM001A-EN-P - May 2022
165
Chapter 7 Configure the Armor PowerFlex Drive
2. Choose a Stop Mode from the pull-down menu. See
Table 67 - Motor Stop Modes
3. Enable or disable the Bus Regulator function.
The Bus Regulator reduces the Decel Rate as required to help prevent the
DC Bus Voltage from increasing to the trip limit.
4. Enable or disable the Flux Brake function.
The flux brake can be enabled for Ramp stop mode. It only applies to
certain motor types, such as AC induction.
Flux Braking causes over fluxing of the motor which reduces the motor
speed faster than just the decel ramp alone. This feature is not intended
for high inertia loads because over fluxing can cause excessive heat in the
motor. Very long decel times can create heat.
Configure DC Brake
DC Brake attributes need to be adjusted when DC Brake is set for the Stop
Mode or when the stop mode is Ramp to stop and DC Brake Injection is
desired to hold the load in place for certain period of time after a ramped stop.
Default values are drive rating dependent and listed in the Armor PowerFlex
AC Drives CIP Objects and Attributes Reference Data, publication
Modes
Description
Coast
When a stop is initiated, power to the motor is immediately removed resulting in an
uncontrolled stop.
Ramp (default)
When a stop is initiated, power to the motor is not interrupted, but the velocity is
reduced to zero at a rate defined by the Deceleration Time. Power to the motor is not
removed until zero velocity is achieved. This is a controlled stop.
DC Brake
When a stop is initiated, power to the motor is not interrupted, but a user configured
amount of DC current is injected into the motor to produce a more rapid stop. After
either a fixed period or when the velocity reaches zero, power to the motor is removed.
ATTENTION:
The bus regulator function is useful to help prevent
nuisance overvoltage faults that result from aggressive
decelerations, overhauling loads, and eccentric loads. However,
it can also cause either of the following two conditions to occur.
•
Fast positive changes in input voltage or imbalanced input
voltages can cause uncommanded positive speed changes
•
Actual deceleration times can be longer than commanded
deceleration times — (However, a Stall Fault is generated if the
drive remains in this state for 1 minute. If this condition is
unacceptable, Bus Regulator must be disabled. In addition,
installing a properly sized dynamic brake resistor provides equal
or better performance in most cases.)
Attribute
Range
Description
DC Brake Level
0…4.14 A
This setting defines the maximum DC brake current, in Amps,
applied to the motor when Stop Mode is set to Ramp to Stop or DC
Brake Stop. See
.
DC Brake Time
0…99.9 s
This setting specifies the length of time that DC brake current is
injected into the motor. See