Rockwell Automation 1336T FORCE Series B - Manual (Page 228)

Chapter 6
Troubleshooting
6–16
At point B, the motor was no longer in regeneration and the bus voltage
had dipped below the nominal range. If the drive compared point B with
point A, the drive would have seen a bus drop of 150V and entered
precharge. However, because the drive compared point B with the bus
voltage tracker, the bus drop was less than 150V and the drive continued
operating.
At point C, the bus voltage had dropped 150V and the drive entered a
precharge state.
Precharge / Ridethrough Selection provides the following options for
changing the slew rate:
This
bit: With this
text:
Sets the slew rate to:
0 Slew Rate 1
10V/second. This option is the most sensitive to
changes in the actual bus voltage.
1 Slew Rate 2 5V/second.
2 Slew Rate 3 0.5V/second.
3 Slew Rate 4 0.05V/second.
4 Slew Rate 5
0.005V/second. This option is the least
sensitive to changes in the actual bus voltage.
If all bits are clear (0), the slew rate is 0.05V/second. If more than one
bit is set, the first bit that is set is used for the slew rate. For most
applications, the default slew rate of 0.05V/second, which is 1 volt in 20
seconds, should be appropriate.