Troubleshooting 10-57 – Rockwell Automation 1557 MEDIUM VOLTAGE AC DRIVE User Manual

Page 299

TROUBLESHOOTING

10-57

1557-UM050F-EN-P – June 2013

FAULT / ALARM

PROBABLE CAUSE

RECOMMENDED ACTION

RATED I FEEDBACK
WARNING

1. THE CURRENT FEEDBACK

SCALING IS OUT OF RANGE

1A. CHECK THE PARAMETER AND

ENSURE PROPER VALUES ARE
ENTERED FOR C. T. RATIO. (P149)
C. T. LINE BURDEN (P151).

B. CHECK THE PARAMETERS AND

ENSURE PROPER VALUES ARE
ENTERED FOR LEM RATIO (P150) AND
C. T. MOTOR BURDEN RESISTOR
(P152).

TACH ROTATION
WARNING

1. THE TACH FEEDBACK SIGNALS

FROM PHASE „A‟ AND PHASE „B‟
INTERCHANGED

CHECK THE CABLING FROM
TACHOMETER TO DRIVE AND
CORRECT THE WIRING.

MOTOR OVERSPEED

1. LOSS OF LOAD

1A. CHECK THE APPLICATION AND

CHANGE THE SPEED REGULATOR
BANDWIDTH.

B. CHECK THE PARAMETER (P185) FOR

MOTOR OVERSPEED TRIP AND
INCREASE THE VALUE AS REQUIRED
BASED ON THE APPLICATION.

LINE HARDWARE
WATCHDOG
MOTOR HARDWARE
WATCHDOG

1. DRIVE CONTROL BOARD

HARDWARE FAILURE

2. DEFECTIVE EPROMs

1A. REPLACE DRIVE CONTROL BOARD
B.

ENSURE THAT EEPROM‟S ARE
INSTALLED CORRECTLY IN CORRECT
SOCKETS (EEPROM‟S INSERTED
BACKWARDS WILL NO LONGER BE
USABLE)

2A. REPLACE EEPROMs

LINE SOFTWARE
WATCHDOG,
MOTOR SOFTWARE
WATCHDOG

1. DRIVE CONTROL BOARD

HARDWARE FAILURE

2. FIRMWARE BUG

1A. REPLACE DRIVE CONTROL BOARD
B. RESET FAULT AND RESTART

2A. IF FAULT PERSISTS, ASK FACTORY IF

FIRMWARE UPDATE WILL ELIMINATE
PROBLEM

LINE SOFTWARE
OVERCURRENT,
MOTOR SOFTWARE
OVERCURRENT,
MOTOR HARDWARE
OVERCURRENT

1. OVERCURRENT TRIP

PARAMETERS SET TOO LOW
RELATIVE TO TORQUE LIMIT

2. CURRENT REGULATOR IN LIMIT

3. FLUX REGULATOR IN LIMIT

4. SHORTED THYRISTORS

1A. OVERCURRENT TRIP PARAMETERS

SHOULD BE INCREASED IF TORQUE
LIMIT INCREASED ABOVE DEFAULT
SETTING.

2A. IF LINE FIRING ANGLE IS STUCK AT

ADVANCE LIMIT (8 DEGREES),
CURRENT CONTROL MAY BE LOST.
INCREASE LINE VOLTAGE OR
DECREASE MOTOR FLUX COMMAND.

3A. IF MAGNETIZING CURRENT (LX)

COMMAND IS STUCK AT EXCITATION
LIMIT, CONTROL OF MOTOR VOLTAGE
IS LOST. INCREASE EXCITATION
LIMIT PARAMETER

4B. RESTART DRIVE TO ALLOW STARTUP

DIAGNOSTICS TO DETECT ANY
SHORTED THYRISTORS.