English-
31
Fault
Name
Fault Descriptions
Corrective Actions
Low voltage
The AC motor drive detects
that the DC bus voltage has
fallen below its minimum
value.
1.
Check whether the input voltage falls within
the AC motor drive rated input voltage range.
2.
Check whether the motor has sudden load.
3.
Check for correct wiring of input power to R-S-
T (for 3-phase models) without phase loss.
Over current
Abnormal increase in current.
1.
Check if motor power corresponds with the AC
motor drive output power.
2.
Check the wiring connections to U/T1, V/T2,
W/T3 for possible short circuits.
3.
Check the wiring connections between the AC
motor drive and motor for possible short
circuits, also to ground.
4.
Check for loose contacts between AC motor
drive and motor.
5. Increase
the
Acceleration Time.
6.
Check for possible excessive loading
conditions at the motor.
7.
If there are still any abnormal conditions when
operating the AC motor drive after a short-
circuit is removed and the other points above
are checked, it should be sent back to
manufacturer.
Over voltage
The DC bus voltage has
exceeded its maximum
allowable value.
1.
Check if the input voltage falls within the rated
AC motor drive input voltage range.
2.
Check for possible voltage transients.
3.
DC-bus over-voltage may also be caused by
motor regeneration. Either increase the Decel.
Time or add an optional brake resistor (and
brake unit).
4.
Check whether the required brake power is
within the specified limits.
Overheating
Heat sink temperature too high
1.
Ensure that the ambient temperature falls
within the specified temperature range.
2.
Make sure that the ventilation holes are not
obstructed.
3.
Remove any foreign objects from the
heatsinks and check for possible dirty heat
sink fins.
4.
Check the fan and clean it.
5.
Provide enough spacing for adequate
ventilation.
Overload
The AC motor drive detects
excessive drive output current.
NOTE: The AC motor drive
can withstand up to 150% of
the rated current for a
maximum of 60 seconds.
1. Check whether the motor is overloaded.
2. Reduce torque compensation setting in
Pr.07.02.
3. Take the next higher power AC motor drive
model.
Overload 1
Internal electronic overload trip
1. Check for possible motor overload.
2. Check
electronic
thermal overload setting.
3. Use a higher power motor.
4. Reduce the current level so that the drive
output current does not exceed the value set by
the Motor Rated Current Pr.07.00.