Rockwell Automation 7000 PowerFlex Medium Voltage AC Drive (B Frame) - Classic Control - Manual (Page 438)

7-16 Troubleshooting
7000-UM150I-EN-P – June 2013 7000 “B” Frame
FAULT
MESSAGE
FAULT
CODE
DESCRIPTION RECOMMENDED ACTIONS
Motor Neutral OV 67 The Neutral-to-Ground voltage measured
from the Output Filter Capacitor Neutral
point has exceeded Ground Fault
Overvoltage Trip (P189) for the duration set
in Ground Fault Overvoltage (P190). This
value is displayed in V Motor Neutral
(P347).
– Insulation Failure – Megger the motor
insulation/motor cables/drive insulation to
ground
– Verify the integrity of the output
grounding network if applicable
– Megger the input Isolation Transformer
Secondaries/Input Cables to ground
– Verify Parameter settings are appropriate
for AC Line Reactor or Isolation
Transformer drives
– Verify the integrity of Motor Filter
Capacitors, looking for short circuits or
signs of physical damage. Refer to
Chapter 6 of the User‟s Manual for
detailed instructions on Testing Filter
Capacitors.
Motor OC 21 The measured motor current I Stator (P340)
has exceeded Motor Overcurrent Trip
(P177) for the duration set in Motor
Overcurrent Delay (P178). Possible Causes:
– Real OC/Transients
– Bad Burden resistor/Current Sensor
Circuit Failure – Check components
– Parameter settings too low compared to
torque limit – Verify Parameter settings
– Current regulator in limit (check line
voltage and Alpha line while running)
Motor OL 65 A Motor Overload condition has been
detected, where the overload condition is
calculated using I Stator(P340) and an
algorithm based on Motor Overload Trip
(P179) as the absolute trip level, Motor
Overload Delay (P180) as the base trip delay,
and Motor Overload Min (P351) as the point
where the overload calculation begins.
– Transient Loading - Check torque limit
and overload settings and Compare
loading to torque settings and trip
settings
– Burden Resistor – Check LEM feedback
and Check the burden resistors
Motor OV 22 The measured Motor AC Voltage has
exceeded Motor Overvoltage Trip (P181) for
the duration set in Motor Overvoltage Delay
(P182). Possible Causes:
– Parameter setting incorrect (flux
command/trip values)
– VSB damage – Check VSB resistors,
grounds, and verify tap settings are
correct
– Self-Excitation – Check for flying
start/induced motor rotation