Allen-Bradley 1407-CGCM-DLR, User Manual, Page: 176 / 268

176 Rockwell Automation Publication 1407-UM002B-EN-P - February 2019
Chapter 7 Troubleshooting
Generator overvoltage (59) Rapid loss of large load
Gains mis-adjusted Check AVR gains Calculate/adjust gains as required
Generator undervoltage (27) Over load
Wiring error Check VT wiring. See Voltage
metering troubleshooting Correct wiring as required
Loss of sensing (60FL) Fuse open Check VT fuses Replace as required
Wiring error Check for open connections and
phase rotation reversal Correct wiring as required
Loss of permanent magnet
generator (PMG/Excitation power)
(27) Supply circuit breaker trip/fuse open Check PMG supply. Measure with
voltmeter at CGCM-DLR unit PMG
input terminals
Correct/replace PMG input
protection as required
Wiring error Check PMG supply. Measure with
voltmeter at CGCM-DLR unit PMG
input terminals Correct wiring as required
PMG failure Check PMG supply. Measure with
voltmeter at CGCM-DLR unit PMG
input terminals Repair as required
Incorrect configuration Check single-phase versus 3-phase
selection Correct as required
Reverse VAR (40Q) Under-excitation Check UEL configuration if
necessary Correct as required
Incorrect operating mode selected Check selected operating mode for
operating requirements Select as appropriate
Over-frequency (81O) Governor error Correct as required
Under-frequency (81U) Governor error Correct as required
Reverse power (32R) Governor error Correct as required
Rotating diode monitor Failed diode Remove and test diodes Replace diode
Incorrect configuration Confirm test / setup of diode
monitor parameters with active
parameters Correct as required
Insufficient number of fly back
diodes that are installed Check number of external flyback
diodes that are installed at
CGCM-DLR excitation output if
necessary Install as required
Phase rotation error (47) Wiring error See troubleshooting voltage
metering,
Table 30
Correct wiring as required
Generator over-current (51) Fault or large load condition
Incorrect configuration Check configuration Correct as required
Table 34 - Protection
Symptom Most Likely Cause Diagnostic Action Corrective Action