ov

The deceleration time is too short and too much regenerative energy is flowing back into the drive.

• 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.

The acceleration time is too short.

• 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].

The braking load is too large.

Connect a dynamic braking option to the drive.

There are surge voltages in the input power supply.

Connect a DC reactor to the drive.

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.

If the drive detects ov in these conditions, the speed search-related parameters are incorrect:

• During speed search

• During momentary power loss recovery

• When the drive starts again automatically

• When you use an IE3 premium efficiency motor

• 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 then set b3-24 = 1 [Speed Search Method Selection = Speed Estimation].

• Use these values to adjust the parameters.

  • b3-03 [Speed Search Deceleration Time] = default value × 2

  • L2-03 [Minimum Baseblock Time] = default value × 2

  • L2-04 [Powerloss V/f Recovery Ramp Time] = default value × 2

The power supply voltage is too high.

Decrease the power supply voltage to match the drive rated voltage.

The braking resistor or braking resistor unit wiring is incorrect.

Correct wiring errors in the connection to the braking resistor or braking resistor unit.

The encoder cable is disconnected or wired incorrectly.

Examine for wiring errors or disconnected wires in the encoder cable, and repair problems.

Noise interference along the encoder cable.

Isolate the encoder cable from the drive output line or a different source of electrical interference.

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.

The load inertia is set incorrectly.

• Examine the load inertia settings with KEB, overvoltage suppression, or stall prevention during deceleration.

• Adjust L3-25 [Load Inertia Ratio] to match the qualities of the machine.

You used the Short Circuit Braking function when A1-02 = 5 [Control Method Selection = OLV/PM].

Connect a braking resistor to the drive.

There is motor hunting.

• Adjust n1-02 [Hunting Prevention Gain Setting].

• Adjust n2-02 [Automatic Freq Regulator Time 1] and n2-03 [Automatic Freq Regulator Time 2].

• Adjust n8-45 [Speed Feedback Detection Gain] and n8-47 [Pull-in Current Comp Filter Time].

Speed Search at Start does not complete correctly when:

• A1-02 = 8 [Control Method Selection = EZOLV]

• E9-01 = 0 [Motor Type Selection = Induction (IM)]

Set b3-24 = 2 [Speed Search Method Selection = Current Detection 2].

The drive detects ov [Overvoltage] when A1-02 = 2 [OLV] and 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 this parameter setting is: n2-02 [Automatic Freq Regulator Time 1] ≤ n2-03. When you adjust n2-03, you must also increase the C4-06 [Motor 2 Torque Comp Delay Time] value by the same ratio.

• Increase C4-06 in 10 ms increments.

  Note:

  Make sure that this parameter setting is: C4-02 [Torque Compensation Delay Time] ≤ C4-06. When you adjust C4-06, you must also increase the n2-03 [Automatic Freq Regulator Time 2] value by the same ratio.