YASKAWA GA700 Series

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Troubleshooting

7.4 Fault

YASKAWA SIEPC71061705H GA700 Series Technical Manual 347

Code Name Causes Possible Solutions

Noise interference along the encoder cable Isolate the encoder cable from the drive output line or a different

source of electrical interference.

Note:

• The drive detects this error if motor rotation position moves during Zero Servo.

• Do a Fault Reset to clear the fault.

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.

Use the keypad to set the date and time.

Note:

• Do a Fault Reset to clear the fault.

• Parameter o4-24 [bAT Detection Selection] enables and disables TiM detection.

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] settings.

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.

• Do a Fault Reset to clear the fault.

• If the drive detects this error, it will operate the motor as specified by the Stopping Method set in 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] settings.

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.

• Do a Fault Reset to clear the fault.

• If the drive detects this error, it will operate the motor as specified by the Stopping Method set in 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:

• Do a Fault Reset to clear the fault.

• If the drive detects this error, it will operate the motor as specified by the Stopping Method set in L6-08.

Code Name Causes Possible Solutions

Uv1 DC Bus Undervoltage

There is a phase loss in the drive input power. Correct errors with the wiring for main circuit drive input power.

There is loose wiring in the drive input power

terminals.

Tighten the terminal screws to the correct tightening torque.

The drive input power voltage is changing too

much.

• Examine the input power for problems.

• Make the drive input power stable.

• If the input power supply is good, examine the magnetic

contactor on the main circuit side for problems.

There was a loss of power. Use a better power supply.

The main circuit capacitors have become

unserviceable.

Examine the capacitor maintenance time in monitor U4-05

[CapacitorMaintenance]. If U4-05 is more than 90%, replace the

control board or the drive. For information about replacing the

control board, contact Yaskawa or your nearest sales

representative.

The relay or contactor on the soft-charge bypass

relay is damaged.

U4-06 [PreChargeRelayMainte] shows the performance life of

the soft-charge bypass relay. If U4-06 is more than 90%, replace

the board or the drive. For information about replacing the board,

contact Yaskawa or your nearest sales representative.

Note:

• The drive detects this error if the DC bus voltage decreases below the level set in L2-05 [Undervoltage Detection Lvl (Uv1)] while the drive is running.

• The Uv1 detection level is approximately 190 V for a 200 V class drives. The detection level is approximately 380 V for 400 V class drives. The detection level is