Ride through timeout fault precharge operation, Ride through timeout fault, Precharge operation – Rockwell Automation 20D PowerFlex 700S AC Drives with Phase II Control Reference Manual User Manual
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Rockwell Automation Publication PFLEX-RM003E-EN-E - January 2011
Chapter 1 Detailed Drive Operation
down occurs (extended power loss). If the power loss duration is very short or
there is sufficient input impedance to limit the inrush current when power
returns, the drive will continue normal operation after the disturbance passes.
However, if the power returns causing a large inrush current (precharge device is
still bypassed) drive damage is likely.
Note:
When parameter 406 [Power Loss Mode] is set to 0 “Coast” or 5 “Flux
Only” and the drive is in a ride through condition, the HIM displays the
alarm icon (bell), the alarm queue displays F92 “RideThru” and bit 27
“Reserved” of parameter 328 [Alarm Status 3] is set until incoming
power returns or the drive faults.
Ride Through Timeout Fault
Parameter 407 [Power Loss Time] sets the amount of time allowed to pass for the
incoming power to return before a ride through fault occurs. This limits the time
within which an auto-start for the drive could occur. The default value for this
time is 2 seconds, with a minimum value of 0 seconds and a maximum value of 60
seconds. The ride through timeout fault is shown in Parameter 321 [Exception
Event2], bit 8 “RidethruTime”. The ride through timeout fault will inhibit the
drive auto start function requiring a fault clear and commanded start to run the
drive again.
Precharge Operation
The drive will not run until the controller's precharge function has completed.
Also, the precharge function in the drive runs independent of drive precharge
hardware (for the most part) and the hardware control. The drive will not restart
precharge any time that the drive is running (see
). The drive control is in precharge (or bus capacitor charging mode) any
time that the precharge is not “done” (parameter 555 [MC Status] bit 11
“PreChrg Done” = 0). This process is independent of whether or not the drive
control actually controls the precharge hardware.
For the control to complete precharge and allow drive enable, the following five
conditions must be met:
ATTENTION: The user must determine the safe amount of time allowed
for the drive to automatically start.