YASKAWA VS-626M5, Instruction Manual, Page: 190 / 305

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Table 12.2 Inverter Faults (continued)
Fault No. Name Contents Corrective Actions Error Code
Main circuit
undervoltage
Main circuit DC bus voltage became
lower than undervoltage detection
level during run.
Check the input supply voltage.
FFFf
Control cir-
cuit under-
voltage Control circuit power supply became
lower than undervoltage detection
level.
Check the control supply voltage.
FFFf
Winding
selection
fault
Winding selection was not completed
within set time.
S
Check the control constant
C1-25.
S
Check magnetic contactor wir-
ing for winding selection.
FFfF
Emergency
stop fault
Inverter did not stop within 10 se-
conds after emergency stop com-
mand.
S
Check control constant C1-25.
S
Check the setting of control
constant C1-24 and whether ex-
ternal torque limit signals TLL
and TLH are input.
FFfF
Encoder sig-
nal cable dis-
connection
Motor encoder signal was discon-
nected or connected improperly. Check the wiring of encoder sig-
nal lines.
FFff
Motor over-
speed Motor speed exceeded 120% of set
rated speed.
S
Confirm that encoder signal
lines are separated from main
circuit or other power lines.
S
Check the control constants.
FFff
Excessive
speed devi-
ation
Speed falls to less than 50% of refer-
ence value.
S
Check if the load is heavy or a
tool is jammed.
S
Check whether external torque
limit signals TLL and TLH are
input.
S
Check the control constants.
S
Check the wiring of encoder sig-
nal lines.
FFff
Load fault
Inverter output (U/T1, V/T2, W/T3)
was disconnected.
Check Inverter output wiring.
FFff
Motor Lock
Detection
(For IP mo-
tors only) The motor is locked. (The motor
speed remains at 35 min
− 1
or lower
for 10 seconds during the torque
reference saturation.)
S
Check if the load is heavy or a
tool is jammed.
S
Check the wiring between In-
verter and motor.
S
Check the wiring of encoder sig-
nal lines.
S
Make sure that the motor shaft
rotates.
S
Check if a motor fault or a con-
tact between rotor and stator oc-
curs, or if a bearing is damaged.
FFff
Motor over-
heat 1 Motor temperature exceeded upper
limit (minor fault).
S
Check the wiring.
S
Confirm that motor cooling air is
normal with power ON.
C fi th t th f i t
FfFF
Motor over-
heat 2 Motor temperature over upper limit
continued for over one minute.
S
Confirm that the fan is not
clogged with dust or oil.
S
Check the wiring of motor
thermistor signal lines.
FfFF
12
Troubleshooting