Rockwell Automation SA3100 AC Power Modules - Manual (Page 51)

Diagnostics and Troubleshooting 4-5
4.3.13 UDC Run Fault (Bit 14)
The UDC Run Fault bit is set if the UDC task stops while the minor loop is running in
the PMI Regulator.
4.3.14 Communication Lost Fault (Bit 15)
LED indicator: COMM OK
The COMM OK LED is turned off, and the Communication Lost Fault bit is set if the
fiber-optic communication between the PMI processor and the UDC module is lost
due to two consecutive errors of any type.
4.4 Power Module Warnings (UDC Register 203/1203)
The PMI Regulator will check for conditions that are not serious enough to shut down
the drive, but may affect its performance. If the PMI Regulator detects any of the
following Power Module warning conditions, it will set the appropriate bit in the UDC
Drive Warning Register (203/1203), but it will not shut down the drive. The bits in this
register should be examined by the application task to determine the cause of the
warning. Any resulting action is determined by the application task. No LED indicator
or UDC error code is provided for drive warnings.
4.4.1 DC Bus Overvoltage Warning (Bit 0)
The DC Bus Overvoltage Warning bit is set if the D-C bus voltage rises above the
configured overvoltage threshold value. The torque is automatically limited to avoid
an overvoltage fault. Bit 4 of the Drive Warning Register will also be set to indicate the
torque is being limited by the system.
4.4.2 DC Bus Undervoltage Warning (Bit 1)
The DC Bus Undervoltage Warning bit is set if the D-C bus voltage drops below the
configured undervoltage threshold value. The torque is automatically limited to avoid
a further drop in the DC bus voltage. Bit 4 of the Drive Warning Register will also be
set to indicate the torque is being limited by the system.
4.4.3 Ground Current Warning (Bit 2)
The Ground Current Warning bit is set if ground current exceeds the configured
ground fault current level.
4.4.4 Voltage Ripple Warning (Bit 3)
The Voltage Ripple Warning bit is set if the ripple on the DC bus exceeds the
configured voltage ripple threshold value. This can be used to detect an input phase
loss in the rectifier section, or for a common bus supply.
4.4.5 Reference In Limit Warning (Bit 4)
The Reference in Limit Warning bit is set if the reference to the regulator exceeds the
maximum value permitted (+/- 4095), or is being limited by the system in response to
an overvoltage or undervoltage warning.