Rockwell Automation 20D PowerFlex 700S with Phase I Control Reference Manual - Manual (Page 100)

100 Rockwell Automation Publication PFLEX-RM002D-EN-E - August 2013
Chapter 1 Detail Drive Configuration and Operation
5. The drive precharge delay must be completed. After conditions 1…4 above
are met, parameter 472 [PreCharge Delay] must be completed before the
precharge device bypass is commanded. If any of the above conditions
become false during the precharge delay period, the delay timer is reset. If
parameter 472 [PreCharge Delay] is set less than 200 ms then an internal
200 ms delay is used. Parameter 472 [PreCharge Delay] has a calculated
maximum value based on parameter 410 [PreChrg TimeOut];
[PreCharge Delay] = [PreChrg TimeOut] - 1.0 second.
(Also see Precharge Staging on page
101 for common and shared bus
drives below).
Figure 25 - Precharge Control Functional Diagram
Precharge Timeout Fault
The precharge control logic has an associated precharge timeout fault to alert the
user if the precharge is not completed within the timeout period. Parameter
381[PreChrg Err Cnfg], provides the configuration control for the precharge
timeout fault. Parameter 410 [PreChrgTimeout] sets the period or delay for this
timeout fault (default = 30 seconds). The timeout timer is not started until the
user requests a precharge either through the hardware input (Digital Input 1) or
through parameter 411 [PreChrg Control]. The precharge timeout fault is
intended only to alert the user that there may be a problem in the precharge
control. The precharge fault, for the most part, does not affect the precharge
operation. As conditions would change to complete or restart precharge, the
precharge control will function as described above independent of whether or
not a precharge timeout fault has occurred.
If the drive does not complete precharge due to an unstable bus voltage, then after
the precharge timeout period the precharge control will complete precharge
providing all of other conditions for precharge are met. This control is based on
the precharge timeout status and independent of whether or not the precharge
timeout is configured as a fault, warning or none. This feature could be useful in
cases where bus disturbances are created by another drive in a common or shared
bus installation.
PreChrg
Selection (P838)
S
R
Precharge Request
PreCharge Delay Timer
(P472)
Reset
Precharge Done
(P555 bit 11)
1
select = 14
select not = 14
PreChrg/Disc (14)
Digital Input #1
PreChrg Control (P411)
1=Enable, 0 = Hold PreChrg
Ride Through Active
Enabled (PWM Active)
Low Bus Voltage
Bus Voltage Stable
SET
CLR
Q
Q
S
R
SET
CLR
Q
Q