10-17
[ 12 ]
Fuse blown
Problem The fuse inside the inverter blew.
Possible Causes
What to Check and Suggested Measures
(1) The fuse blew due to
short-circuiting inside the
inverter.
Check whether there has been any excess surge or noise coming from outside.
Take measures against surges and noise.
Have the inverter repaired.
[ 13 ]
Charger circuit fault
Problem The magnetic contactor for short-circuiting the charging resistor failed to work.
Possible Causes
What to Check and Suggested Measures
(1) The control power was not
supplied to the magnetic
contactor intended for
short-circuiting the charging
resistor.
Check that, in normal connection of the main circuit (not a connection via the DC
link bus), the connector (CN R) on the power printed circuit board (power PCB) is
not inserted to NC .
Insert the connector (CN R) to FAN .
Check whether you quickly turned the circuit breaker ON and OFF to confirm
safety after cabling/wiring.
Wait until the DC link bus voltage has dropped to a sufficiently low level and
then release the current alarm. After that, turn ON the power again. (Do not
turn the circuit breaker ON and OFF quickly.)
(Turning ON the circuit breaker supplies power to the control circuit to the
operation level (lighting the LEDs on the keypad) in a short period.
Immediately turning it OFF even retains the control circuit power for a time,
while it shuts down the power to the magnetic contactor intended for
short-circuiting the charging resistor since the contactor is directly powered
from the main power.
Under such conditions, the control circuit can issue a turn-on command to the
magnetic contactor, but the contactor not powered can produce nothing. This
state is regarded as abnormal, causing an alarm.)
(2) Running on single-phase
power
Refer to Section 10.7 "If the Inverter is Running on Single-Phase Power,"
[ 4 ].
[ 14 ]
Overload of motor 1, 2
Problem Electronic thermal protection for motor 1, 2 activated.
Motor 1 overload
Motor 2 overload
Possible Causes
What to Check and Suggested Measures
(1) The electronic thermal
characteristics do not match
the motor overload
characteristics.
Check the motor characteristics.
Reconsider the data of function codes (P99*, F10* and F12*).
Use an external thermal relay.
(2) Activation level for the
electronic thermal protection
was inadequate.
Check the continuous allowable current of the motor.
Reconsider and change the data of function code F11*.
(3) The specified acceleration/
deceleration time was too
short.
Recalculate the acceleration/deceleration torque and time needed for the load,
based on the moment of inertia for the load and the acceleration/deceleration
time.
Increase the acceleration/ deceleration time (F07, F08, E10 through E15,
and H56).
(4) Overload.
Measure the output current.
Reduce the load (e.g. Use the overload early warning (E34) and reduce the
load before the overload protection is activated.). (In winter, the load tends to
increase.)
(5) Excessive torque boost
specified (F09*)
Check whether decreasing the torque boost (F09*) does not stall the motor.
If no stall occurs, decrease the F09* data.