V/f Pattern

Cause:
Fault in the output current detector.

Selecting a setting value

0: V/f constant
This is a typical control method of an inverter, and the inverter is controlled so that the ratio of the output frequency (f) and the output voltage (V) becomes almost constant.
It is applied to loads with equipment like conveyors that requires the same torque at low speeds as at rated speeds.
To increase the torque at low speeds, increase the setting value of [vb: Manual torque boost 1].

1: Variable torque
This is applied to loads such as fans, pumps and blowers in which the torque is proportional to the square of load motor speed.

2: Automatic torque boost
The load current in the speed range from startup to base frequency is detected and the output voltage (torque boost) from the inverter is automatically adjusted. This gives steady torque for stable operation.
It is applied to loads that require torque.
Operation may become unstable depending on loads. In this case, set [Pt] = "0: V/f constant" and increase the value of [vb: Manual torque boost 1].
When [Pt] is "2", setting of motor parameters is required. See “setting of motor parameters” section below for additional information

3: Vector control 1
High-torque and high-precision stable operation is realized in the speed range from startup to base frequency.
It is applied to load transporting machinery and elevators that require high torque and machine tools that require high precision.
• High starting torque can be obtained.
• It is effective when smooth stable operation from a low speed is required.
• The change of motor speed caused by load fluctuation is suppressed to realize high-precision operation.
When [Pt] is "3", setting of motor parameters is required. See “setting of motor parameters” section below for additional information

4: Energy savings
Energy can be saved in all speed ranges by detecting load current and flowing the optimum current that fits the load.
When [Pt] is "4", setting of motor parameters is required. See “setting of motor parameters” section below for additional information

5: Dynamic energy savings (for fan and pump)
Energy can be saved in all speed ranges by detecting load current and flowing the optimum current that fits the load. Even in a low-speed range with especially decreased efficiency, more substantial energy savings than those provided when [Pt] is "4: Energy savings" can be achieved by controlling to maximize the efficiency.
The inverter cannot respond to rapid load fluctuations, so this setting should be used only for loads, such as fans and pumps that have less load fluctuations.
When [Pt] is "5", setting of motor parameters is required. See “setting of motor parameters” section below for additional information

6: PM motor control
Permanent magnet motors (PM motors) that are highly efficient can be operated in sensor-less operation.
Setting of parameters for PM motor is required.

7: V/f 5-point setting
V/f control characteristics can be created according to machinery. Set frequency and voltage in five points and run the inverter with V/f control characteristics derived by connecting these points.
Set five points from VF1 to VF5 with the following parameters [F190] to [F199].

9: Vector control 2 (speed / torque)
It is applied to torque control.
Vector control realize high-torque and high-precision stable operation in the speed range from startup to base frequency.
It is applied to load transporting machinery and elevators that require high torque and machine tools that require high precision.
• High starting torque can be obtained.
• It is effective when smooth stable operation from a low speed is required.
• The change of motor speed caused by load fluctuation is suppressed to realize high-precision operation.
When [Pt] is "9", setting of motor parameters is required. See “setting of motor parameters” section below for additional information

10: PG feedback control
Vector control is performed by using speed feedback signals from the motor.
Attach the PG feedback option to the inverter. Use a motor with speed sensor (encoder) and connect signals from the encoder to the PG feedback option.
In the following cases, use [Pt] = "11: PG feedback vector control (speed / torque)"
• To perform torque control
• To perform speed control that requires high precision
• When low-speed operation (with motor slip frequency or less) of regeneration is required
When [Pt] is "10", setting of motor parameters is required. See “setting of motor parameters” section below for additional information

11: PG feedback vector control (speed / torque)
Vector control is performed by using feedback signals from the motor. It is applied to high-precision speed control and torque control.
Attach the PG feedback option to the inverter. Use a motor with speed sensor (encoder) and connect signals from the encoder to the PG feedback option.
Torque control is performed based on the torque command, so the motor speed depends on the relationship between the load torque and the motor generated torque.

When [Pt] is “11", setting of motor parameters is required. See “setting of motor parameters” section below for additional information

Cautions for automatic torque boost and vector control
• Look at the motor name plate and be sure to set the following parameters.
- [vL: Base frequency 1] (Rated frequency)
- [vLv: Base frequency voltage 1] (Rated voltage)
- [F405: Motor rated capacity]
- [F415: Motor rated current]
- [F417: Motor rated speed]
• The vector control exerts its characteristics effectively within the speed range of [vL: Base frequency 1]. The same characteristics will not be obtained in speed ranges over the base frequency.
• When using vector control, set [vL: Base frequency 1] in the range of 40 to 120 Hz.
• Use a three-phase motor with a capacity that is the same as the inverter's rated capacity or one rank below. The minimum applicable motor capacity is 0.1 kW.
• Use a motor that has 2 to 16 P.
• Operate one motor in combination with one inverter. Vector control cannot be used when one inverter is operated with more than one motor. When using a combination of several motors, set [Pt] to "0: V/f constant".
• The maximum length of wires between the inverter and motor is 30 m. If the wires are longer than 30 m, be sure to perform offline auto-tuning with the wires connected. However, the effects of voltage drop due to resistance of wiring cause motor-generated torque in the vicinity of base frequency to be somewhat lower.
• When a reactor or motor-end surge voltage suppression filter is connected between the inverter and a motor, the motor's generated torque may fall. Performing offline auto-tuning may also cause a trip "Etn1". When a trip has occurred, connect the inverter and the motor directly to perform offline auto-tuning, or set motor parameters by referring to the test record of the motor.
• Attach the speed sensor used for PG feedback control directly to the motor. If it is attached via gear, etc., rigidity is not ensured, causing hunting of the motor or a trip of the inverter.
• If the motor is not connected or a motor with extremely small capacity is connected for operation for the purpose of operation check of the inverter, etc., set [Pt] to "0: V/f constant" temporarily. If it is set to Automatic torque boost or Vector control, normal operation may not be possible.

Cautions for PM motor control
• If the motor is not connected or a motor with extremely small capacity is connected for operation for the purpose of operation check of the inverter, etc., set [Pt] to "0: V/f constant" temporarily. If it is set to PM motor control, normal operation may not be possible.

Cautions for motor control
• Set the upper limit for frequency command to a value which is three or four times the value of [vL]. • The value of run frequency is limited to a value which is ten times or less the values of [vL], and the alarm "A-05" will appear when it is exceeded.
• If the inclination of the set V/f is over 8.25%/Hz, the alarm "A-02" will appear.

Setting of motor parameters
First, look at the motor name plate and set the following parameters.
• [vL: Base frequency 1] (Rated frequency)
• [vLv: Base frequency voltage 1] (Rated voltage)
• [F405: Motor rated capacity]
• [F415: Motor rated current]
• [F417: Motor rated speed]
Next, perform auto-tuning.
Setting with [F400: Offline auto-tuning]:
Set [F400: Offline auto-tuning] to "5".
*If an auto-tuning error occurs, set motor parameters individually.

Please reference latest AS3 Instruction Manual more details or latest information.

AS3 fault codes, descriptions, symptoms and suggested remedies can be found in the below links. Each fault code can also be linked to directly from the AS3 by accessing the QR code on a mobile device while the AS3 is currently experiencing the fault.