Fault display Type Enable Potential causes and corrective actions
xx Blocking Timeout
xx = cell that is faulted
F Fixed Cause
Blocking test timeout. A cell failed the blocking test. No subsequent
switching test will be performed on the cell.
Action
Check cell, or back EMF too high.
xx Switching Timeout
xx = cell that is faulted
F Fixed Cause
Switching test timeout. A device failed the switching test after success‐
fully passing blocking.
Action
Check cell, or back EMF too high to run the test.
xx Bad Cell Data
xx = cell that is faulted
F Fixed Cause
For non-AP cells, the mode returning does not match requested mode
data.
For AP cells, the returned data is not as expected (EPLD status lower 4 bits
does not equal Dh).
Action
1. Check ber optic connections on both CCB and DCR end.
2. Change CCB.
xx Cell Fault/Modulator
xx = cell that is faulted
F Fixed Cause
Cell is showing a fault, but no fault is able to be determined.
Action
1. Check ber optic connections on both CCB and DCR end.
2. Change CCB.
xx DC Bus Dischrge alrm
xx = cell that has alarm
A Fixed Cause
For HV Cells, upon removal of the input voltage, a discharge bleeding
resistor connects across the DC bus in 3 seconds. Failure to turn on causes
the alarm.
Action
Cell must be repaired. Failure in this circuit allows an unsafe voltage to
remain in the cell for an extended time.
Troubleshooting Faults and Alarms
11.12 Cell Faults and Alarms
NXGPro+ Control Manual
Operating Manual, A5E50491925A 473