Troubleshooting
7
7.5 Minor Faults/Alarms
YASKAWA SIEPC71061753C GA500 Technical Manual 285
Code Name Causes Possible Solutions
PGo Encoder (PG) Feedback Loss
The encoder cable is disconnected or wired
incorrectly.
Examine for wiring errors or disconnected wires in the encoder
cable, and repair problems.
The encoder is not receiving power. Examine the encoder power supply.
The holding brake is stopping the motor. Release the holding brake.
Note:
• The drive detects this error if it does not receive the speed detection pulse signal from the encoder in the detection time set in F1-14 [Encoder Open-Circuit Detect Time].
• If the drive detects this error, the terminal assigned 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 F1-02 [PG Open Circuit Detection Select].
Code Name Causes Possible Solutions
rUn Motor Switch during Run
The drive received a Motor 2 Selection [H1-xx =
16] during run.
Make sure that the drive receives the Motor 2 Selection while the
drive is stopped.
Note:
If the drive detects this error, the terminal set to H2-01 to H2-03 = 10 [MFDO Function Selection = Alarm] will activate.
Code Name Causes Possible Solutions
SE Modbus Test Mode Error
MEMOBUS/Modbus communications self-
diagnostics [H1-xx = 67] was done while the drive
was running.
Stop the drive and do MEMOBUS/Modbus communications self-
diagnostics.
Note:
If the drive detects this error, the terminal set to H2-01 to H2-03 = 10 [MFDO Function Selection = Alarm] will activate.
Code Name Causes Possible Solutions
SToF Safe Torque OFF Failure
One of the two terminals H1-HC and H2-HC
received the Safe Disable input signal.
The Safe Disable input signal is wired incorrectly.
• Make sure that the Safe Disable signal is input from an
external source to terminals H1-HC or H2-HC.
• When the Safe Disable function is not in use, connect
terminals H1-HC and H2-HC.
There is internal damage to one Safe Disable
channel.
Replace the board or the drive. For information about replacing
the control board, contact Yaskawa or your nearest sales
representative.
Note:
If the drive detects this error, the terminal assigned to H2-01 to H2-03 = 10 [MFDO Function Select = Alarm] will be ON.
Code Name Causes Possible Solutions
TiM Keypad Time Not Set
There is a battery in the keypad, but the date and
time are not set.
Set the date and time with the keypad.
Note:
• Parameter o4-24 [bAT Detection Selection] enables and disables TiM detection.
• If the drive detects this error, the terminal set to H2-01 to H2-03 = 10 [MFDO Function Selection = Alarm] will activate.
Code Name Causes Possible Solutions
TrPC IGBT Maintenance Time (90%)
The IGBT is at 90% of its expected performance
life.
Replace the IGBT or the drive. For information about replacing
the control board, contact Yaskawa or your nearest sales
representative.
Note:
If the drive detects this error, the terminal set to H2-01 to H2-03 = 10 [MFDO Function Selection = Alarm] will activate.
Code Name Causes Possible Solutions
UL3 Undertorque Detection 1
A fault occurred on the machine.
Example: There is a broken pulley belt.
Examine the machine and remove the cause of the fault
The parameters are incorrect for the load. Adjust L6-02 [Torque Detection Level 1] and L6-03 [Torque
Detection Time 1].
Note:
• The drive detects this error if the drive output current is less than the level set in L6-02 for longer than L6-03.
• If the drive detects this error, the terminal set to H2-01 to H2-03 = 10 [MFDO Function Selection = Alarm] will activate.
• Set the conditions that trigger the minor fault using L6-01 [Torque Detection Selection 1].
Code Name Causes Possible Solutions
UL4 Undertorque Detection 2
A fault occurred on the machine.
Example: There is a broken pulley belt.
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].
Note:
• The drive detects this error if the drive output current is less than the level set in L6-05 for longer than L6-06.
• If the drive detects this error, the terminal set to H2-01 to H2-03 = 10 [MFDO Function Selection = Alarm] will activate.
• Set the conditions that trigger the minor fault using L6-04 [Torque Detection Selection 2].
Code Name Causes Possible Solutions
UL5 Mechanical Weakening Detection 2
The drive detected undertorque as specified by the
conditions for mechanical weakening detection set
in L6-08 [Mechanical Fatigue Detect Select].
Examine the machine for deterioration.
Note:
• If the drive detects this error, the terminal set to H2-01 to H2-03 = 10 [MFDO Function Selection = Alarm] will activate.
• If the drive detects this error, it will operate the motor as specified by the Stopping Method set in L6-08.