
7-5
LED Display
Description
Cause
Possible Solutions
Operator
Communication
Error 2
Communication error
between AC Drive and LCD
keypad.
● LCD keypad and AC Drive can
transmit data but transmission
error occurs for more than 2
seconds
● Disconnect the operator
and then reconnect.
● Replace control board.
Current
Transducer
Error
Three phase input voltage
detection level error
● Input voltage abnormal
● Input voltage noise is too high
● Control board malfunction
● Check input voltage and
the voltage signal of control
board
PTC Error
PTC wires disconnected
● PTC wires disconnected for
more than 10 seconds.
● Check the motor and GND
connection
Operator
Disconnection
When 00-02=0 and operator
is disconnected while AC
Drive is running. Fault action
selection set by parameter
16-09.
● When 00-02=0, warning is
displayed when operator is
disconnected.
● Check the keypad operator
connection.
Short Circuit
AC Drive output short circuit
or ground fault.
● Short circuit or ground fault
(08-23 = 1).
● Motor damaged (insulation).
● Wire damage or deterioration.
● Check motor wiring.
● Disconnect motor and try
running the AC Drive.
Table 7.2.2 Warning/Self-diagnosis and Corrective Actions
LED Display
Description
Cause
Possible Solutions
OV (Flash)
Over Voltage
DC bus voltage exceeds the
OV detection level
:
240V class
:
410Vdc
480V class
:
820Vdc
(For 480V class, if input
voltage 01-14 is set lower
than 400V, the OV detection
value is decreased to
700Vdc)
● Deceleration time set too short,
resulting in regenerative energy
flowing back from motor to the
AC Drive.
● The AC Drive input voltage is
too high.
● Use of power factor correction
capacitors.
● Excessive braking load.
● Braking transistor or resistor
defective.
● Speed search parameters set
incorrectly.
● Increase deceleration time
● Reduce input voltage to
comply with the input
voltage requirements or
install an AC line reactor to
lower the input voltage.
● Remove the power factor
correction capacitor.
● Use dynamic braking unit.
● Replace braking transistor
or resistor.
● Adjust speed search
parameters.
LV (Flash)
Low Voltage
DC bus voltage is lower than
the UV detection level or the
pre-charge contactor is not
active while the AC Drive is
running.
190Vdc
:
240V class;
380Vdc
:
480V class
(the detection value can be
adjusted with parameter
07-13)
● The input voltage is too low.
● Input phase loss.
● Acceleration time set too short.
● Input voltage fluctuation.
● Pre-charge contactor damaged.
● DC bus voltage feedback signal
value incorrect.
● Check the input voltage.
● Check input wiring.
● Increase acceleration time.
● Check power source
● Replace pre-charge
contactor
● Replace control board or
AC Drive.