Rockwell Automation 1336T FORCE Series B - Manual (Page 239)

Chapter 6
Troubleshooting
6–27
Several faults have been included to identify some problems that can
occur in the resistance measuring routine. If the drive trips during the
resistance test, check bits 0 through 7 of Motor Stator Resistance Test
Errors (parameter 296):
If this bit
is set:
Then:
0
Motor Not at Zero Speed
The motor is not at zero speed. Generally, this bit is set in two cases:
•
If the motor rotates during this test, an improper result is likely. Make
sure the motor (decoupled from load or process) is not rotating just
before or during the test.
•
If the motor is not rotating during this test, then investigate electrical
noise creating encoder transitions. Improper encoder grounding or a
noisy encoder power supply could cause noise.
This fault cannot be determined for encoderless applications. You must
visually check for this condition on encoderless systems.
If your motor does rotate during this test, consult the factory.
1
Sign Error
A sign error fault occurs when the average voltage is negative. If you
receive a sign error, run the test again because the value returned is not
reliable.
2
Not Used
4
Not Used
6
Not Used
8
Zero Current
If this bit is set, you need to:
1. Set the rated motor current in Nameplate Amps (parameter 4) to the
correct value.
2. Run the test again.
3. Consider replacing the control board.
9
Software Error
A software fault is generated when an improper sequence of events has
occurred. Consider running the test again.
10
Enable Dropout
The drive enable was lost during the resistance test. Consider running the
test again and monitor the drive enable (bit 9 of Inverter Status (parameter
54) and/or the Inv En LED on the main control board).