Manual

Rockwell Automation Publication 1407-UM001G-EN-P - April 2013 153
Troubleshooting Chapter 7
Voltage output is less than setpoint AVR not selected/enabled Check excitation enable (hardware
and software) and AVR select
Correct Logix controller logic or I/O
as required
Wiring error Check wiring for excitation enable,
excitation current output, VT inputs,
fuses open, grounding, and
PMG/supply
Correct wiring as required
Insufficient supply power Measure Voltage at CGCM unit
PMG/supply input terminals
Correct supply anomaly if
insufficient voltage is measured
Measure generator residual voltage
(shunt excitation)
If less than 10V AC, consult
generator manufacturer’s
documentation and flash the
generator field
Generator not up to rated speed Check generator speed Increase generator speed to rated
speed
Correct condition preventing rated
speed from being attained
Field resistance too great Disconnect field current outputs at
CGCM unit and measure load
resistance
Correct/verify load resistance is
within CGCM unit capability
Gain mis-adjusted Check gains entered into CGCM unit
configuration
Calculate/adjust as required
Excitation limiting active Check OEL active input Correct OEL configuration or change
operating point
Droop compensation is driving down
the voltage
Check Droop Enable Adjust/disable droop compensation
Table 20 - Excitation Control - AVR
Symptom Most Likely Cause Diagnostic Action Corrective Action