YASKAWA T103 Installation & Primary Operation page 88

20 Troubleshooting
Code Name
oL4 Overtorque Detection 2
oL5 Mechanical Weakening Detection 1
oL7 High Slip Braking Overload
oPr Keypad Connection Fault
oS Overspeed
ov Overvoltage
88
Causes
A fault occurred on the machine.
Example: The machine is locked.
The drive detected overtorque as specified by the
conditions for mechanical weakening detection set in
L6-08 [Mechanical Fatigue Detect Select].
The load inertia is too large.
The keypad is not securely connected to the
connector on the drive.
There is overshoot.
There is an incorrect number of PG pulses set in the
drive.
The oS detection level is set incorrectly.
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 deceleration time is too short and too much
regenerative energy is flowing back into the drive.
The acceleration time is too short.
The braking load is too large.
There are surge voltages in the input power supply.
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).
The speed search-related parameters are set
incorrectly (this fault also occurs during recovery
from momentary power loss and after Auto Restarts).
The power supply voltage is too high.
The braking resistor or braking resistor unit wiring is
incorrect.
The encoder cable is disconnected or wired
incorrectly.
Noise interference along the encoder cable.
Electrical interference caused a drive malfunction.
YASKAWA TOEPC71061782C GA800 Drive Installation & Primary Operation
Possible Solutions
Examine the machine and remove the cause of the fault.
Do a deterioration diagnostic test on the machine side.
• Decrease deceleration times in C1-02, C1-04, C1-06, and C1-08
[Deceleration Times] for applications that do not use High Slip
Braking.
• Use a braking resistor to decrease the deceleration time.
Examine the connection between the keypad and the drive.
• Decrease C5-01 [ASR Proportional Gain 1] and increase C5-02
[ASR Integral Time 1].
• Adjust the pulse train gain with H6-02 to H6-05 [Pulse Train
Input Setting Parameters].
Set H6-02 [Terminal RP Frequency Scaling] to the pulse train
frequency during 100% reference (maximum motor rotation speed).
Adjust F1-08 [Overspeed Detection Level] and F1-09 [Overspeed
Detection Delay Time].
• 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 L3-04 = 1 [Stall Prevention during Decel = General
Purpose].
• Increase the values set in C1-02, C1-04, C1-06, or C1-08
[Deceleration Times].
• Connect a dynamic braking option to the drive.
• Perform Deceleration Rate Tuning.
• Make sure that sudden drive acceleration does not cause the
fault.
• Increase the values set in C1-01, C1-03, C1-05, or C1-07
[Acceleration Times].
• Increase the value set in C2-02 [S-Curve Time @ End of Accel].
• Set L3-11 = 1 [Overvoltage Suppression Select = Enabled].
Connect a dynamic braking option to the drive.
Connect a DC link choke 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.
1. Examine the motor main circuit cable, terminals, and motor
terminal box, and then remove ground faults.
2. Re-energize the drive.
• Examine the settings for all speed search related parameters.
• Set b3-19 ≠ 0 [Speed Search Restart Attempts ≠ 0 times].
• Adjust b3-03 [Speed Search Deceleration Time].
• Do Stationary Auto-Tuning for Line-to-Line Resistance and set
b3-24 = 1 [Speed Search Method Selection = Speed Estimation].
Decrease the power supply voltage to match the drive rated voltage.
Correct wiring errors in the connection to the braking resistor or
braking resistor unit.
Examine for wiring errors or disconnected wires in the encoder
cable, and repair problems.
Isolate the encoder cable from the drive output line or a different
source of electrical interference.
• 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.