10-3
Inverter faults that can be reset manually or via automatic restart
LED display
Description
Cause
Possible solutions
OC-A
over current at
acceleration
The inverter output
current exceeds the
overcurrent level
(200% of the
inverter rated
current).
Acceleration / Deceleration time is too short.
Contactor at the inverter output side.
A special motor or applicable capacity is
greater than the inverter rated value.
Short circuit or ground fault.
Extend acceleration /
deceleration time.
Check the motor wiring.
Disconnect motor and try
running inverter.
OC-C
over current at
fixed speed
The inverter output
current exceeds the
overcurrent level
(200% of the
inverter rated
current).
Acceleration / Deceleration time is too short.
Contactor at the inverter output side.
A special motor or applicable capacity is
greater than the inverter rated value.
Short circuit or ground fault.
Extend acceleration /
deceleration time.
Check the motor wiring.
Disconnect motor and try
running inverter.
OC-d
over current at
deceleration
The inverter output
current exceeds the
overcurrent level
(200% of the
inverter rated
current).
Acceleration / Deceleration time is too short.
Contactor at the inverter output side.
A special motor or applicable capacity is
greater than the inverter rated value.
Short circuit or ground fault.
Extend acceleration /
deceleration time.
Check the motor wiring.
Disconnect motor and try
running inverter.
OC-S
over current at
start
The inverter output
current exceeds the
overcurrent level
(200% of the
inverter rated
current).
Acceleration / Deceleration time is too short.
Contactor at the inverter output side.
A special motor or applicable capacity is
greater than the inverter rated value.
Short circuit or ground fault.
Extend acceleration /
deceleration time.
Check the motor wiring.
Disconnect motor and try
running inverter.
OV-C
over voltage
during operation
/ deceleration
Excessive Voltage
during operation/
deceleration
Deceleration time setting too short or
excessive load inertia
Power voltage varies widely (fluctuates)
Set a longer deceleration
time
Consider use of a brake resistor
and/or brake module (in case of
400V models)
Consider use of a reactor at the
power input side
PF
input phase loss
Input phase Loss
Abnormal fluctuations in the main circuit
voltage
Check the main circuit power
supply wiring.
Check the power supply voltage
OC
over current
The inverter output
current exceeds the
overcurrent level
(200% of the
inverter rated
current).
Acceleration / Deceleration time is too short.
Contactor at the inverter output side.
A special motor or applicable capacity is
greater than the inverter rated value.
Short circuit or ground fault.
Extend acceleration /
deceleration time.
Check the motor wiring.
Disconnect motor and try
running inverter.