Yaskawa E7B Drive Bypass - Manual (Page 187)

Diagnostic & Troubleshooting 6 - 7
LF
Output Phase Loss
Output Open-phase
An open-phase occurred at the Drive output
This fault is detected when output current
has exceeded 5% imbalance.
There is a broken wire in the
output cable.
There is a broken wire in the
motor winding.
The output terminals were loose.
Check the wiring to the motor.
Check the motor for phase to
ground short.
The motor being used has a
capacity less than 5% of the
Drive’s maximum motor capacity.
Check the motor and Drive
capacity.
Low impedance motor was used. Add additional impedance.
Parameter E2-03 set incorrectly Adjust E2-03 to a lower value.
LL3
Loss of Load Det 1
Loss of Load Detection 1
Drive output current < L6-02 for more than
the time set in L6-03
Motor is underloaded.
Ensure the values in L6-02 and
L6-03 are appropriate.
Check application/machine
status to eliminate fault.
OC
Over Current
Overcurrent
Drive output current exceeded the
overcurrent detection level (approximately
180% of Drive rated output current).
Shorted Drive output phase to
phase, shorted motor, locked
rotor, load too heavy, accel/
decel time too short, contactor
on the Drive output is opened
and closed, a special motor or
a motor with a FLA rating
larger than Drive rated output
current.
Remove the motor and run the
Drive without the motor.
Check the motor for a phase-to-
phase short.
Check the Drive for a phase-to-
phase short at the output.
Verify C1-01 and C1-02 are set
correctly.
Check load conditions.
OH1
Heatsnk MAX Temp
Cooling Fin/Cooling Fin Fan Overheat
The temperature of the Drive cooling fin
exceeded the temperature programmed in
parameter L8-02, and L8-03=0-2.
Cooling fan(s) are not
working, high ambient
temperature, a heat source is
too close to the Drive.
Check for dirt build-up on the
fans and cooling fins.
Reduce the ambient temperature
around the Drive.
Drive Internal Cooling Fan
Remove the heating unit/Replace
the cooling fan.
OH3
Motor Overheat 1
Motor Overheating Alarm
The Drive stops or continues operation
according to the setting of L1-03.
Overheating of motor as
measured by motor thermistor.
Recheck the cycle time and the
size of the load.
Recheck the accel/decel time
(C1-01 and C1-02).
Recheck the V/F pattern (E1-01
thru E1-13).
Recheck the motor rated current
value (E2-01).
OH4
Motor Overheat 2
Motor Overheating Fault
The Drive stops operation according to the
setting of L1-04.
Overheating of motor as
measured by motor thermistor.
Recheck the cycle time and the
size of the load.
Recheck the accel/decel time
(C1-01 and C1-02).
Recheck the V/F pattern (E1-01
thru E1-13).
Recheck the motor rated current
value (E2-01).
Table 6.1 Fault Displays and Processing
Digital
Operator Display
Description Cause Corrective Action