YASKAWA GA500 Maintenance & Troubleshooting page 47

Code Name
oC Overcurrent
YASKAWA TOEPYAIGA5001A GA500 DRIVE MAINTENANCE & TROUBLESHOOTING
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 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 too large.
The drive received a Run command while the motor
was coasting.
In PM Control Methods, the setting of the motor code
is incorrect.
If the drive detects the fault at start or in the low
speed range (10% or less) and n8-57 = 1 [HFI
Overlap Selection = Enabled] for PM Control
methods, the high frequency injection gain is too
high.
The control method is set incorrectly for the motor.
The motor main circuit cable is too long.
Speed search does not complete at start when you set
A1-02 = 8 [EZ Vector Control] and use an induction
motor.
An overcurrent occurred during overexcitation
deceleration.
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] to get the necessary torque.
• Increase the values set in C2-01 to C2-04 [S-Curve
Characteristics] to 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 [PM Motor Settings] correctly.
• Set E5-xx [PM Motor Parameters] correctly or do Rotational
Auto-Tuning.
• Decrease the value of n8-41 [HFI P Gain] in 0.5-unit
increments.
Note:
Set n8-41 > 0.0 for IPM motors.
Set A1-02 [Control Method Selection] correctly.
• Replace the drive with a larger capacity model.
• Decrease C6-02 [Carrier Frequency]. Or set C6-02 = B.
When E9-01 = 0 [Motor Type Selection = Induction (IM)], set b3-
24 = 2 [Speed Search Method Selection = Current Detection Speed
Search].
• Decrease the value set in n3-13 [OverexcitationBraking (OEB)
Gain].
• Decrease the value set in n3-21 [HSB Current Suppression
Level].
2.4 Fault
2
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