Rockwell Automation 1557 MEDIUM VOLTAGE AC DRIVE - Manual (Page 298)

10-56 TROUBLESHOOTING
1557-UM050F-EN-P – June 2013
# FAULT / ALARM PROBABLE CAUSE RECOMMENDED ACTION
38 HARDWARE OVER
CURRENT
1. CT POLARITY / CONNECTIONS
TO GROUND
2. BURDEN RESISTOR DEFECTIVE
3. PARAMETERS ARE NOT
PROGRAMMED PROPERLY.
1A. CHECK THE CT‟s FOR PROPER
POLARITIES AS PER THE DRAWING
B. CHECK THE GROUNDING AT CTS AND
ENSURE THEY ARE FIRM
2A. CHECK THE BURDEN RESISTOR FOR
OPEN CIRCUIT. REPLACE IF
REQUIRED.
B. CHECK THE RIBBON CABLE FROM
PHOENIX CONNECTOR TO LINE SIDE
DRIVE CONTROL BOARD
3A. THE EXCITATION LIMIT IS SET TO
LOW. INCREASE THE VALUE TO 1.5
TIMES ( 1/ L
mag
measured)
B. THE FLUX REGULATOR BANDWIDTH IS
SET HIGH. REDUCE THE BANDWIDTH.
39 12P PHASING 1. INCORRECT PHASE ROTATION
FROM INCOMING POWER
SUPPLY TO DRIVE.
1A. APPLY MV TO DRIVE AND MEASURE
THE PHASE DIFFERENCE BETWEEN
V
12
AND V
23
ON THE LINE DCB V12
SHOULD LEAD V23 BY 120: MEASURE
V12 AND V31 ON LINE DCB, V12
SHOULD LEAD BY 240: IF NOT
CORRECT, SWAP ANY 2 PHASES ON
THE PRIMARY SIDE OF THE
ISOLATION TRANSFORMER.
RECHECK MEASUREMENTS.
B. PERFORM CONTINUITY CHECKS ON
CABLES BETWEEN IS0 XFORMER AND
DRIVE, ENSURE THE DELTA A OF ISO
XFORMER IS CONNECTED TO DELTA
A OF DRIVE AND SO FORTH.
40 DRIVE UNSTABLE 1. CHECK THE OUTPUT
VOLTAGE/CURRENT
WAVEFORMS
1A. SCOPE THE OUTPUT VOLTAGE AND
CURRENT WAVEFORMS AND CHECK
THE VOLTAGE AND CURRENT
FEEDBACK.
B. CHECK THE VFB FOR ANY OPEN
RESISTORS.
C. CHECK THE INTEGRITY OF
GROUNDING IN THE DRIVE AND
EXTERNAL GROUNDING.
41 NEUTRAL OVER
VOLTAGE FAULT 1. NEUTRAL GROUND VOLTAGE
HAS EXCEEDED THE VALUE
SET IN PARAMETER P189 FOR
THE DURATION SET IN
PARAMETER P190.
2. CHECK OUTPUT CAPACITORS
1A. CHECK THE MOTOR WINDING
INSULATION TO GROUND.
B. MEGGER THE CABLES FROM DRIVE
OUTPUT TO MOTOR, AS PER
PROCEDURE.
C. CHECK THE OUTPUT GROUNDING
NETWORK IN THE DRIVE.
D. CHECK THE ISOLATION
TRANSFORMER WINDINGS AND THE
CABLES TO THE DRIVE WITH A
MEGGER.
2A. CHECK THE INTEGRITY OF THE
CAPACITORS.