68 
 
Symptoms  Conditions  Possible causes  Solutions 
Under the three-wire control mode, 
the terminal with the three-wire 
operation control function is not 
closed. 
Set and close the three-wire operation control 
terminal 
Fault alarm occurs.  Troubleshoot 
The virtual terminal function of the 
host device is set improperly. 
Cancel the virtual terminal function of the host 
device or set the function properly through the 
host device, or modify the P09.15 setting 
The forward/reverse logic of the 
input terminal is set improperly. 
Check the P09.14 setting 
When the 
drive is 
started, the 
report -LU- 
runs 
immediately. 
The thyristor or the 
contactor disconnects 
and the drive load is 
large. 
Since the thyristor or the contactor 
is not closed, when the drive runs 
with large load, the DC bus voltage 
of the main circuit will drop; the 
drive will display -LU- first and will 
not display Er.JCF fault. 
Run the drive after the thyristor or the 
contactor is closed completely