YASKAWA GA700 Technical Manual page 347

Code Name
oC Overcurrent
YASKAWA ELECTRIC SIEP C710617 05F YASKAWA AC Drive GA700 Technical Manual
Causes
The load is too heavy.
Overheating caused damage to the
motor or the motor insulation is not
satisfactory.
The motor main circuit cable is
contacting ground to make a short
circuit.
A short circuit or ground fault on the
drive output side caused damage to the
output transistor of the drive.
The acceleration/deceleration time is too
short.
The drive is trying to operate a
specialized motor or a motor that is
larger than the maximum applicable
motor output of the drive.
A magnetic contactor was switched at
the output.
The V/f pattern settings are incorrect.
The torque compensation gain is too
large.
Electrical interference caused a
problem.
The gain during overexcitation
operation is set too large.
The drive received a Run command
while the motor was coasting.
The motor code is set incorrectly for PM
Control Methods.
Possible Solutions
• Measure the current flowing into the motor.
• Replace the drive with a larger capacity model if
the current value is more than the drive rated
current.
• Decrease the load or replace with a larger drive
to prevent sudden changes in the current level.
Measure the motor insulation resistance, and
replace the motor if there is electrical conduction or
unserviceable insulation.
• Examine the motor main circuit cable for
damage, and repair short circuits.
• Measure the resistance between the motor main
circuit cable and the ground terminal. If there is
electrical conduction, replace the cable.
• Make sure that there is not a short circuit in
terminal B1 and terminals U/T1, V/T2, and W/
T3. Make sure that there is not a short circuit in
terminals - and terminals U/T1, V/T2, and W/
T3.
• If there is a short circuit, contact Yaskawa or
your nearest sales representative.
• Calculate the torque necessary during
acceleration related to the load inertia and the
specified acceleration time.
• Increase the values set in C1-01, C1-03, C1-05,
or C1-07 [Acceleration Times] until you get the
necessary torque.
• Increase the values set in C2-01 to C2-04 [S-
Curve Characteristics] until you get the
necessary torque.
• Replace the drive with a larger capacity model.
• Examine the motor nameplate, the motor, and
the drive to make sure that the drive rated
current is larger than the motor rated current.
• Replace the drive with a larger capacity model.
Set the operation sequence to not turn ON or OFF
the magnetic contactor while the drive is outputting
voltage.
• Examine the ratios between the V/f pattern
frequency and voltage. Decrease the voltage if it
is too high compared to the frequency.
• Adjust E1-04 to E1-10 [V/f Pattern Parameters].
For motor 2, adjust E3-04 to E3-10.
Decrease the value set in C4-01 [Torque
Compensation Gain] to make sure that the motor
does not stall.
Examine the control circuit lines, main circuit
lines, and ground wiring, and decrease the effects
of electrical interference.
• Find the time when the fault occurs.
• If the fault occurs at the same time as
overexcitation operation, decrease the value set
in n3-13 [OverexcitationBraking (OEB) Gain]
and consider the motor flux saturation.
• Examine the sequence and input the Run
command after the motor fully stops.
• Set b3-01 = 1 [Speed Search at Start Selection =
Enabled] or set H1-xx = 61, 62 [Speed Search
from Fmax or Fref] to input speed search
commands from the MFDI terminals.
• Enter the correct motor code to E5-01 [PM
Motor Code Selection] as specified by the PM
motor.
• For specialized motors, refer to the motor test
report and set E5-xx correctly.
6.4 Faults
6
347