JUKI LH-4500C Series Instruction Manual page 90

Error
Description of error
code
E731 Motor hole sensor fault
Reverse rotation of motor ・ When the motor runs at a speed
E733
E750 Sewing machine stops
E811 Over-voltage
E813 Low voltage
E815 Regenerative resistor is
not connected
E900 Main shaft motor IPM
overcurrent protection
E901 Main shaft motor IPM
overload
E903 85-V power supply fault
E904 24-V power supply fault
E910 The presser motor origin
retrieval error
E912 Main shaft motor speed
detection error
E915 Failure of communication
with operation panel
E918 Main shaft temperature
error
E922 Main shaft control failure
E924 Motor driver fault
E946 Machine-head EEPROM
write error
Cause
・ In the case the motor signal is not
input properly.
of 500 sti/min. or more, the motor
runs in the reverse direction of the
indicated direction of rotation.
・ In the case the optional-input safe-
ty switch is pressed.
・ In the case a voltage that is equal
to or more than the guaranteed
voltage is input.
・ In the case a voltage of 200 V is
applied though the voltage is set to
100 V.
・ In the case a voltage of 220 V is
input to the box of "JA: 120 V".
・ In the case a voltage of 400 V is
applied to the box of "CE: 230 V".
・ In the case the regenerative resis-
tor is not connected.
・ Maloperation of the main shaft
motor.
・ In the case the 85-V voltage is not
properly output.
・ In the case the 24-V voltage is not
properly output.
・ In the case the presser motor has
failed to return to its origin.
・ In the case communication with the
operation panel cannot be carried
out.
・ In the case the temperature of the
CTL PCB is excessively high.
・ In the case the main shaft motor is
out of control.
・ In the case the motor driver has
broken.
・ In the case the machine head PCB
is not correctly connected.
– 85 –
Item to be checked
・ Check whether the motor signal connector
has loosened or slipped off.
・ Check whether the motor signal cord has
broken by being caught under the machine
head.
・ Check whether the insertion direction of the
motor encoder connector is correct.
・ Check whether the main shaft motor encod-
er wire connection is correct.
・ Check whether the main shaft motor wire
connection for power is correct.
・ Check whether the supply voltage of "rated
supply voltage ±10 % or more" is applied.
・ Check whether the 100 V/200 V change-
over connector is set correctly.
In the above-described cases, the power PCB
has broken.
・ Check whether the regenerative resister
is connected to the regenerative resistor
connector (CN11).
・ Check whether the stepping motor is faulty.
・ Check the F2 fuse.
・ Check whether the presser setting is correct
(memory switch No. 23).
・ Check whether the presser motor origin has
been correctly adjusted.
・ Check whether CN32 has loosened or
come off.