Rockwell Automation 1336T FORCE Series B - Manual (Page 240)

Chapter 6
Troubleshooting
6–28
What Happens If Multiple Opens Occur?
If multiple opens occur, several additional faults may be indicated. For
example, if transistor U upper and U lower are open, the test also
indicates that current feedback U phase is open. Because current cannot
run through phase U, the current feedback device cannot be checked and
therefore is listed as a malfunction The type of installation often
determines which parts of the transistor diagnostics may or may not
work. As a result, treat the software only as an aid for testing the power
structure.
What Do I Do If I Get a Software Fault?
If bit 0 of Inverter Diagnostics Result # 1 (P 258) is set to 1, an improper
sequence of events has occurred. Either the software cannot distinguish
what is occurring, or there is noise in the system. If a fault occurs
repeatedly, the problem may be a fault that the software cannot directly
identify (for example, a voltage breakdown in a snubber). If this is the
case, you need to determine through external measurements if the
problem is real or if there is a noise problem. In cases where a specific
test continually results in nuisance faults, use Transistor Diagnostics
Configuration (parameter 257) to disable that test.