Rockwell Automation 20D PowerFlex 700S AC Drives with Phase II Control Reference Manual - Manual (Page 144)

144 Rockwell Automation Publication PFLEX-RM003E-EN-E - January 2011
Chapter 1 Detailed Drive Operation
Speed Feedback Loss Ride Through Configuration
Setting up the feedback loss ride through function requires the following steps:
1. Enter a valid feedback device selection in parameter 222 [Mtr Fdbk Sel
Pri].
2. Enter a valid feedback device selection in parameter 223 [Mtr Fdbk Sel
Alt]. Default value is 2 “Sensorless”.
3. Set parameter 365 [Fdbk LsCnfg Pri] to 1 “Alarm”.
4. Set parameter 366 [Fdbk LsCnfg Alt] to 2 “FltCoastStop” (recommended
but not necessary).
5. Set the speed change detection level in parameter 224 [TachSwitch Level].
6. Set parameter 153 [Control Options], bit 16 “Auto Tach Sw” to 1 for
automatic switch over, when [Mtr Fdbk Sel Alt] is not set to 2 “Sensorless”.
7. Set parameter 153 [Control Options], bit 19 “Slip Comp En” to 1 so that
slip compensation is enabled when switching over to sensorless mode.
Automatic and manual switching of feedback devices is inhibited if a loss is
sensed on the device to which switching was to take place. The drive will fault
when it is configured for speed feedback loss ride through and the primary device
fails when the alternate device has failed and is also configured to fault. If the
alternate device is not configured to fault, then switching to the alternate device
will be inhibited and operation on the primary feedback device will continue.
Note that operation on the primary device will continue even when the device
fails, since the device must be configured for an alarm to allow for automatic
device switch over.
FdbkLoss
Detect
300
Logic Command
(TachLoss Rst)
Motor Spd Fdbk
to Speed
Regulator 0
1
151 2
155 12
153 16
Control Options
Speed Feedback
from Primary Device
Speed Feedback
from Alternate Device
(AutoTach Sw)
Logic Status
(Tach Loss Sw)