Rockwell Automation 1336T Master/Slave Parallel AC Drv - Manual (Page 41)

1336 FORCE-5.19 – August, 2000
Troubleshooting 4-3
It is suggested that before attempting a cable replacement, that the
main boards be replaced to check the TB12, TB13 connectors. Start
with the Main Control board on the Master Drive first and then
proceed to the Slave Main Control board before replacing the cable.
When replacing the Master/Slave cable, note the orientation of the
cable and the number of wraps as it passes thru the ferrite cores at the
top of each cabinet. When checking the wiring between the Master
and Slave drives, TB12 and TB13 should be wired 1 to 1. That is pin
1 of TB12 on the Master is wired to pin 1 of TB12 on the Slave and
pin 1 of TB13 on the Master to pin 1 of TB13 on the Slave.
Tach/Encoder Faults - It is possible that under certain drive setup
configurations, a tach/encoder loss on one drive would allow the
master drive to attempt to ride thru the loss of the slave and control
the motor alone. A tip off that only the master drive is operational is a
cogging sound from the motor as it attempts to run off only one set of
windings. If the motor attempts to run using only the master during a
fault situation, check the configuration of the tach/encoder loss fault
on each drive. The tach/encoder loss fault must be set as operational
on both the Master and Slave for encoder operation. (Refer to Chapter
5 for information on Encoderless Operation.)
Stall Delay Problems - If the Stall Delay (Typically 5.0 Sec.) is not
set the same for both drives this could cause a Motor Stalled
{Parameter 88) fault under certain conditions. Check that Parameter
91 (Stall Delay) is set the same on both drives (typically 5 seconds on
a M/S Drive).
Drive Enable Problems - The M/S Enable Timeout can occur if the
drives are not started in the correct sequence (Slave first), or if the
Master drive enable link with the Slave is not completed within 1
second after the enable is commanded. The Slave drive will indicate
that it is enabled and in the ready state when the Slave LED on the
Slave Main Control Board begins to blink. If the Master Drive does
not enable within 1 second (Master Enable LED will turn on), check
that the Slave drive has been set up to enter the “flux” mode upon
enable. This can be accomplished by entering a value of 12 in
parameter 273 (Testpoint Select #1) and monitoring parameter 274
(Testpoint Data #1) to see if the precharge has been completed on the
Slave drive. Bits 8 & 11of parameter 223 (Precharge/Ridethru Select)
should also be checked to determine if a fast fluxup is enabled (Bit 8)
or whether a precharge exit is being forced (Bit 11).