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6 TROUBLE SHOOTING
AC motor drive is provided with functions of warning and protection such as over voltage, low voltage
and over current. Once fault occurs, protection function shall act, AC motor drive output stop, fault
contactor act and also free running of motor shall stop. For causes and corrective measures of fault,
display of fault shall be taken for reference. Fault records shall be stored into computer memory inside
AC motor drive (fault records for recent six times shall be available), and records shall be read at
digital control panel.
Attention shall be paid that, depressing RESET after fault shall only be available after fault has been
eliminated.
6.1 Fault and corrective measures
Descriptions of fault
Corrective measures
AC motor drive detects Over current at
output side.
1. Check rated current of motor complies
with that of AC motor drive.
2. Check that there is no short circuit in
U/t1-V/t2-W/T3.
3. Check that no short circuit or grounding
occur to connection of motor.
4. Check that screws are securely tightened
to AC motor drive.
5. Increase acceleration time (1-09, 1-10).
6. Check there is no over load to motor.
AC motor drive detects Over voltage at
DC high voltage side.
1. Check input voltage is within rated voltage
range of AC motor drive, and see that no
voltage surge occurs.
2. If over voltage occurs at DC high voltage
side of AC motor drive caused by inertia
back up voltage, deceleration time shall be
increased.
AC motor drive detects over heat,
exceeding protection level.
1. Check that ambient environment is not
over heat.
2. Check radiator and air fan is running.
3. Check enough clearance for air flowing is
provided to AC motor drive is with.
DC high voltage side over low inside
AC motor drive.
1. Check power supply voltage is correct.
2. Check no sudden heavy load.
Output current exceeds allowable
current of AC motor drive. 65 sec shall
be in station if 150% of rated current of
AC motor drive is output.
1. Check motor over load.
2. Decrease torque (7-02) to improve set
value.
3. Increase output capacity of AC motor
drive.
Inner electric relay protection acts
1. Check motor over load.
2. Check rated current (07-00) of motor is
proper.
3. Check electric relay function setting
4. Increase motor capacity.
Motor load overlarge
1. Check motor load is not overlarge.
2. Check over-torque detection level setting
(06-03).
