YASKAWA GA700 Series

7.5 Minor Faults/Alarms
356 YASKAWA SIEPC71061705H GA700 Series Technical Manual
Code Name Causes Possible Solutions
oL4 Overtorque 2
A fault occurred on the machine.
Example: The machine is locked.
Examine the machine and remove the cause of the fault.
The parameters are incorrect for the load. Adjust L6-05 [Torque Detection Level 2] and L6-06 [Torque
Detection Time 2] settings.
Note:
• The drive detects this error if the drive output current is more than the level set in L6-05 for longer than L6-06.
• If the drive detects this error, the terminal assigned to H2-01 to H2-03 = 10 [MFDO Function Select = Alarm] will be ON.
• Set the conditions that trigger the minor fault using L6-04 [Torque Detection Selection 2].
Code Name Causes Possible Solutions
oL5 Mechanical Weakening Detection 1
The drive detected overtorque as specified by the
conditions for mechanical weakening detection set
in L6-08 [Mechanical Fatigue Detect Select].
Do a deterioration diagnostic test on the machine side.
Note:
• If the drive detects this error, the terminal assigned to H2-01 to H2-03 = 10 [MFDO Function Select = Alarm] will be ON.
• If the drive detects this minor fault, it will operate the motor as specified by the Stopping Method set in L6-08.
Code Name Causes Possible Solutions
oS Overspeed
There is overshoot. • Decrease C5-01 [ASR Proportional Gain 1] and increase C5-
02 [ASR Integral Time 1].
• Use H6-02 to H6-05 [Pulse Train Input Setting Parameters] to
adjust the pulse train gain.
There is an incorrect number of PG pulses set in the
drive.
Set H6-02 [Terminal RP Frequency Scaling] to the pulse train
frequency during 100% reference (maximum motor rotation
speed).
The oS detection level is set incorrectly. Adjust F1-08 [Overspeed Detection Level] and F1-09 [Overspeed
Detection Delay Time].
Note:
• The drive detects this error if the motor speed is more than the value set in F1-08 for longer than F1-09.
• If the drive detects this error, the terminal set to H2-01 to H2-03 = 10 [MFDO Function Select = Alarm] will activate.
• If the drive detects this error, it will operate the motor as specified by the stopping method set in F1-03 [Overspeed Detection Selection].
Code Name Causes Possible Solutions
ov Overvoltage
There are surge voltages in the input power supply. Connect a DC reactor to the drive.
Note:
If you turn the phase advancing capacitors ON and OFF and
use thyristor converters in the same power supply system,
there can be surge voltages that irregularly increase the input
voltage.
The drive output cable or motor is shorted to ground
(the current short to ground is charging the main
circuit capacitor of the drive through the power
supply).
1. Examine the motor main circuit cable, terminals, and motor
terminal box, and then remove ground faults.
2. Re-energize the drive.
The power supply voltage is too high. Decrease the power supply voltage to match the drive rated
voltage.
Electrical interference caused a drive malfunction. • Examine the control circuit lines, main circuit lines, and
ground wiring, and decrease the effects of electrical
interference.
• Make sure that a magnetic contactor is not the source of the
electrical interference, then use a Surge Protective Device if
necessary.
• Set L5-01 ≠ 0 [Number of Auto-Restart Attempts ≠ 0 times].
The drive detects ov [Overvoltage] when:
• The acceleration completes
• The deceleration starts
• The load changes suddenly
• Increase the value set in n2-03 [Automatic Freq Regulator
Time 2] in 50 ms increments.
Note:
Make sure that you set n2-02 ≤ n2-03. When you adjust n2-
03, you must also increase the C4-06 [Motor 2 Torque Comp
Delay Time] value by same ratio.
• Increase C4-06 in 10 ms increments.
Note:
Make sure that you set C4-02 ≤ C4-06. When you adjust C4-
06, you must also increase the n2-03 value by same ratio.
Note:
• The drive detects this error if the DC bus voltage is more than the ov detection level when there is no Run command (while the drive is stopped).
• The ov detection level is approximately 410 V with 200 V class drives. The detection level is approximately 820 V for 400 V class drives.
• If the drive detects this error, the terminal set to H2-01 to H2-03 = 10 [MFDO Function Select = Alarm] will activate.
Code Name Causes Possible Solutions
ovEr Too Many Parameters Changed
You tried to change more than 150 parameters. Make sure that parameters that do not have an effect on drive
operation are at their default settings.
Note:
• You can change 150 parameters maximum.
• If you change parameters that have dependencies, the drive
can detect ovEr when the number of changed parameters is
fewer than 150.