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V/f Control

Table 1. Parameters for Fine Tuning the Drive (A1-02 = 0 [V/f])

Issue

Parameter Number

Possible Solutions

Default

Recommended Setting

Hunting or oscillation at mid-range speeds (10 Hz to 40 Hz)

n1-02 [Hunting Prevention Gain Setting]

  • If torque is not sufficient with heavy loads, decrease the setting value.

  • If hunting or oscillation occur with light loads, increase the setting value.

  • If hunting occurs with a low-inductance motor, for example a motor with a larger frame size or a high-frequency motor, lower the setting value. Set n1-01 = 1 [Hunting Prevention Selection = Enabled].

1.00

0.10 - 2.00

  • The volume of the motor excitation sound is too high.

  • Hunting or oscillation at low speeds (10 Hz or lower), or at mid-range speeds (10 Hz to 40 Hz)

C6-02 [Carrier Frequency Selection]

  • If the volume of the motor excitation sound is too high, increase the carrier frequency.

  • If hunting or oscillation occur at low or mid-range speeds, decrease the carrier frequency.

1 (2 kHz) 1

1 to upper limit value

  • Unsatisfactory motor torque and speed response

  • Hunting or oscillation

C4-02 [Torque Compensation Delay Time]

  • If torque or speed response are slow, decrease the setting value.

  • If hunting or oscillation occur, increase the setting value.

200 ms 2

100 ms to 1000 ms

  • Torque at low speeds (10 Hz or lower) is not sufficient.

  • Hunting or oscillation

C4-01 [Torque Compensation Gain]

  • If torque at low speeds (10 Hz or lower) is not sufficient, increase the setting value.

  • If hunting or oscillation occur with light loads, decrease the setting value.

1.00

0.50 - 1.50

  • If you use the drive with an IE3 high efficiency motor, the current that is more than the motor rated current will flow and trip at overload. Hunting or oscillation.

C4-01 [Torque Compensation Gain]

Decrease the setting value in these conditions:

  • Drive trips at overload.

  • Hunting or oscillation.

1.00

0.00 - 1.00

  • Torque at low speeds (10 Hz or lower) is not sufficient.

  • Large initial vibration at start up.

  • E1-08 [Mid Point A Voltage]

  • E1-10 [Minimum Output Voltage]

  • If torque at low speeds (10 Hz or lower) is not sufficient, increase the setting value.

  • If there is large initial vibration at start up, decrease the setting value

  • E1-08: 16.0 V 3

  • E1-10: 12.0 V 3

Default setting +/- 5 V 4

Speed precision is unsatisfactory.

C3-01 [Slip Compensation Gain]

Set E2-01 [Motor Rated Current], E2-02 [Motor Rated Slip], and E2-03 [Motor No-Load Current], then adjust C3-01.

0.0 (no slip compensation)

0.5 - 1.5
 
1

The default setting changes when the settings for C6-01 [Normal / Heavy Duty Selection] and o2-04 [Drive Model (KVA) Selection] change.

2

The default setting changes when the settings for A1-02 [Control Method Selection] and o2-04 change.

3

The default setting changes when the settings for A1-02 and E1-03 [V/f Pattern Selection] change.

4

Recommended settings are for 200 V class drives. Multiply the voltage by 2 for 400 V class drives.