Mitsubishi Electric MELSERVO-J4 Instruction Manual page 142

2. TROUBLESHOOTING FOR MR-CV_POWER REGENERATION CONVERTER UNIT
No. Name/Description
71 Undervoltage
The power supply
voltage dropped.
72 Cooling fan error
The speed of the
cooling fan on the
power
regeneration
converter unit has
decreased.
73 Regenerative error
The load ratio
exceeded the
excessive
regeneration
protection
characteristic of
the power
regeneration
converter unit.
75 Overvoltage
The value of the
bus voltage
exceeded the
prescribed value.
200 V class: 420 V
DC
400 V class: 840 V
DC
Cause
(1) The power supply
wiring is incorrect.
(2) Power supply voltage is
low.
(3) An instantaneous
power failure has
occurred for 60 ms or
longer.
(4) A part in the power
regeneration converter
unit is malfunctioning.
(1) Foreign matter was
caught in the cooling
fan.
(2) Cooling fan life expired. Check if the cooling
(1) The regenerative load
ratio exceeded 100%.
(1) The regeneration
capacity is insufficient.
(2) Power supply voltage
high.
(3) A ground fault or short
occurred at the servo
motor power cable.
(4) A ground fault occurred
at the servo motor.
(5) Something near the
device caused it.
2 - 5
Check method Check result
Check the power It has a failure.
supply wiring.
It has no failure.
Check if the power The voltage is the
supply voltage is at prescribed value or
the prescribed value lower.
or lower.
The voltage is
200 V class: 190 V DC
higher than the
400 V class: 380 V DC prescribed value.
Check if the power It has a problem.
has a problem.
It has no problem.
Disconnect the cables It is repeatable.
except for the power
supply, and then
check the
repeatability.
Check if a foreign Something has
matter is caught in the been caught.
cooling fan.
Nothing has been
caught.
It is stopping.
fan is stopping.
Check "Converter It is 100% or more.
regenerative load
ratio" with MR
Configurator2.
Set a longer It is not repeatable.
deceleration time
constant, and then
check the
repeatability.
It is repeatable.
Check if the voltage of It is higher than the
the input power supply prescribed value.
is over the prescribed
value.
It is at the
200 V class: 297 V AC
prescribed value or
400 V class: 594 V AC lower.
Check if only the servo It is shorted.
motor power cable is
shorted.
It is not shorted.
Disconnect the servo It is shorted.
motor power cables on
motor side, and check
It is not shorted.
insulation among
phases (U, V, and W).
Check the noise, It has a failure.
ambient temperature,
etc.
Action
Wire it correctly.
Check (2).
Review the power
supply voltage.
Check (3).
Review the power.
Check (4).
Replace the power
regeneration
converter unit.
Remove the foreign
matter.
Check (2).
Replace the power
regeneration
converter unit.
Reduce the
frequency of
positioning.
Reduce the load.
Check operation
pattern.
Or use a larger
converter unit.
Check (2).
Reduce the power
supply voltage.
Check (3).
Replace the servo
motor power cable.
Check (4).
Replace the servo
motor.
Check (5).
Take
countermeasures
against its cause.