69
Protection func-
tion
Error causes
Action to be taken
Low
voltage
protec-
tion
Main
circuit
voltage
low
Inverter capacity is too small.
Voltage drop due to wiring.
A motor of large capacity (11 kW or
greater) connected to the same power
system has been started.
Rapid acceleration with generator
power supply
Operation sequence when power is off
Defective electromagnetic contactor
Check the power capacity and power sys-
tem.
UV display appears when the Inverter power
is turned off while operation signal is input.
Remove the power after stopping the
Inverter.
Overcurrent
protection
Extremely rapid accel/decel
Motor on/off switching at the Inverter
output side
Motor of a capacity greater than the
Inverter rating has been started.
High-speed motor or pulse motor has
been started.
Inverter output has been short cir-
cuited.
Transistor error may occur. Investigate the
error cause, correct it, then restart.
Ground-fault
protection
Ground-fault at the Inverter output side
Overvoltage
protection
Over voltage
Insufficient deceleration time
Regenerative load (Motor is turned by
the load.)
High input voltage compared to motor
rated voltage
If braking torque is not proper, extend the
decel time or use a braking resistor.
Fuse blown
Repeated overcurrent protection (OC)
Repeated overload protection (OL2)
power reset
Rapid deceleration in excess excitation
(improper V/f characteristic setting)
Turn off the power supply once and turn it
on again.
If the fault occurs again after replacement,
replace the Inverter.
Cooling fin overheat Defective cooling fan
Ambient temperature rise
Clogged filter
Replace the cooling fan and clean the filter.
Ambient temperature: 104
°
F (40
°
C) or less
[113
°
F (45
°
C) or less with top cover off]
Overload
protec-
tion
Motor
Overload, low speed operation or
extended acceleration time, improper
V/f characteristic setting
Investigate the cause of overload and
review the operation pattern, V/f characteris-
tic, and motor/inverter capacities.
Inverter
(If Inverter is repeatedly reset after an over-
load occurs, the Inverter may fault. Investi-
gate and correct the cause of overload.)
Over
torque
detec-
tion
Motor current exceeds the preset value
because of machine error or overload
Check the use of the machine. Correct the
overload cause or set a higher detection
level which is within the allowable range.
External fault signal
input
External fault condition occurred.
Correct the cause of the fault input.
Control circuit fault
thermistor fault
External noise
Excess vibration or shock
Record all data of
cpf04
, then make initial-
ization.
Turn off power, then turn on again. If error is
persistent, replace the Inverter.
Fault Display
Section 3-1
