Rockwell Automation 20A PowerFlex 70EC/700VC - Manual (Page 49)

Flux Braking 45
Following is a brief list of each configurable fault. Some of these faults are
explained in more detail in their own section of this document.
Flux Braking Flux braking is used to provide extra braking capability without the use of a brake
resistor, by taking advantage of the losses in a motor. Flux braking can be used not
only to brake a load to a complete stop, but also to brake a load from one speed to a
lesser speed. For a complete list of methods that will bring the load to a complete
stop, see "Stop Modes" on
page 109 .
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, but only when braking is required. In general, the flux
current is not increased when the motor is at or above rated speed. At higher speeds,
field weakening is active and the motor flux current cannot be increased.
Because flux braking increases motor losses, the duty cycle used with this method
must be limited. Check with the motor vendor for flux braking or DC braking
application guidelines. Also consider using external motor thermal protection.
Bit Fault Description
0 Power Loss
1 Undervoltage
2 Reserved
3 Motor Overload
4 Shear Pin
5 Auto Restart Tries
6 Decel Inhibit
7 Motor Thermistor
8 Input Phase Loss
9 Load Loss
10 Reserved
11 Shear Pin No Accel
12 Output Phase Loss
13 PTC Hardware
70EC 700VC 700H
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