Flux Braking - Allen-Bradley PowerFlex 70 Reference Manual

Flux Braking

Resetting faults will clear the faulted status indication. If any fault condition still
exists, the fault will relatch and another entry made in the fault queue.
Clearing the Fault Queue
Performing a fault reset does not clear the fault queue. Clearing the fault queue is
a separate action.
Fault Configuration
The drive can be configured such that some fault conditions do not trip the drive.
Configurable faults include those that are user inputs.
[Fault Config 1] is a bit-mapped 16 bit word enabling or disabling certain fault
conditions (see below). Disabling a fault removes the effect of the fault condition
and makes the event unknown to the user. If the bit is on, the fault is enabled. If
the bit is off, the fault is not enabled.
x x x 0 0 x 0 0 0 1
15 14 13 12 11 10 9 8 7 6
Bit # * Vector firmware 3.001 & later
Factory Default Bit Values
Power Up Marker
Copy of factory "drive under power" timer at the last power-up of the drive. Used
to provide relevance of Fault 'n' Time values with respect to the last power-up of
the drive.
This value will rollover to 0 after the drive has been powered on for more than
the hours shown in the Range field (approximately 47.667 years).
You can use flux braking to stop the drive or to shorten the
Vector
deceleration time to a lower speed. Other methods of deceleration or stopping
may perform better depending on the motor and the load.
To enable flux braking:
1. [Bus Reg Mode A, B] must be set to "1" Adjust Freq to enable the bus
regulator.
2. [Flux Braking] must be set to 1 "Enabled".
When enabled, flux braking automatically increases the motor flux resulting in an
increase of motor losses. The flux current is only increased when the bus voltage
regulator is active. When the bus voltage regulator is not active, the flux current is
returned to normal. The maximum flux current is equal to rated motor current
but may be further reduced depending on the load level, IT protection, or current
Rockwell Automation Publication PFLEX-RM001H-EN-P - June 2013
1 =Enabled
0 0 1 x 1 0
0 =Disabled
5 4 3 2 1 0
x =Reserved
Flux Braking
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