How to set acceleration and deceleration times for the Yaskawa V1000 inverter

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In factory automation systems, motor starting and stopping processes must be properly controlled to ensure stable equipment operation, minimize vibration, and reduce mechanical stress on the drive system. If a motor accelerates too quickly, the current may increase significantly, potentially causing the inverter to experience an overload. Conversely, if the motor decelerates too abruptly, the regenerative energy generated by the motor may increase the DC bus voltage, causing the inverter to trigger an overvoltage fault.

For the Yaskawa V1000 series, operators can adjust acceleration and deceleration times through parameter group C1. These parameters are important because they directly affect motor starting, stopping, and speed adjustment processes.

Proper Yaskawa V1000 inverter setup not only ensures smoother equipment operation but also helps protect the motor, reduce equipment failures, and improve production efficiency.

1. Understanding Acceleration and Deceleration Times on the Yaskawa V1000​

Acceleration Time refers to the period during which the inverter adjusts its output frequency from 0 Hz to the maximum frequency configured in parameter E1-04.
Deceleration Time refers to the period during which the inverter reduces its output frequency from the maximum frequency set in E1-04 down to 0 Hz.
These two parameters serve different purposes:

• Acceleration Time: Controls how quickly the output frequency increases when the motor starts or receives an acceleration command.
• Deceleration Time: Controls how quickly the output frequency decreases when the motor receives a deceleration or inverter-controlled stop command.

For example, if the acceleration time is set to 10 seconds, the inverter will use approximately 10 seconds to increase the frequency from 0 Hz to the value configured in E1-04. If E1-04 is set to 50 Hz, the average frequency change rate will be approximately 5 Hz per second.
It is important to note that actual acceleration and deceleration times may be longer than the configured values if stall prevention or current and voltage limiting functions are activated.

2. Important Acceleration and Deceleration Parameters​

On the Yaskawa V1000 inverter, parameter group C1 is used to configure acceleration and deceleration times.
The main parameters include:

Parameter	Function
C1-01	Acceleration Time 1
C1-02	Deceleration Time 1
C1-03	Acceleration Time 2
C1-04	Deceleration Time 2
C1-05	Acceleration Time 3
C1-06	Deceleration Time 3
C1-07	Acceleration Time 4
C1-08	Deceleration Time 4
C1-10	Acceleration/Deceleration Time Setting Unit

Among these parameters, C1-01 and C1-02 are the default settings used in standard configurations. The setting range for parameter group C1 can extend from 0.0 to 6000.0 seconds, depending on the unit configured in C1-10. The default acceleration and deceleration times are both 10 seconds.

In addition, the inverter supports multiple acceleration and deceleration time settings. These settings can be selected through multifunction digital inputs or other supported switching methods.

3. How to Set Acceleration Time Using Parameter C1-01​

C1-01 is the parameter used to configure the first acceleration time. When no switching to another time setting is configured, this parameter is used during motor startup. Follow these steps:

Step 1: Check the motor specifications
Before configuration, identify the motor's rated power, voltage, current, and frequency. Also, check the maximum frequency setting in E1-04 to determine the acceleration range.
Step 2: Access the parameter setting mode
Use the Yaskawa V1000 digital operator to access parameter group C1.
Step 3: Select parameter C1-01
Locate parameter C1-01 on the operator display. This parameter is used to set the first acceleration time.
Step 4: Enter the desired time value
For example, if you want the motor to accelerate over approximately 15 seconds, enter: Then confirm the configured value.
Step 5: Check the operating performance

Issue a RUN command and monitor the acceleration process. If the motor accelerates too quickly, vibrates, or draws excessive current, reassess the acceleration time and actual load conditions.
The acceleration time must be suitable for the mechanical characteristics of the system. For heavily loaded conveyor systems, a longer acceleration time should be considered to reduce mechanical stress on the conveyor belt, gearbox, and other drive components.

4. How to Set Deceleration Time Using Parameter C1-02​

C1-02 is the parameter used to configure the first deceleration time. It determines how quickly the output frequency decreases when the inverter receives a stop or deceleration command using the configured deceleration ramp. Follow these steps:

Step 1: Access parameter group C1 using the inverter keypad.
Step 2: Locate parameter C1-02.
Step 3: Enter the desired deceleration time.
For example, if you want the motor to decelerate over approximately 20 seconds, configure:
Step 4: Confirm and save the setting.
Step 5: Test the system, observe the deceleration process, and check the voltage, current, and displayed warning or fault codes.

In particular, when decelerating high-inertia loads such as industrial fans, flywheels, or long conveyor systems, regenerative energy may cause the DC bus voltage to rise. If the deceleration time is too short, the inverter may generate an overvoltage fault (OV) during deceleration.

In this situation, technicians should consider extending the deceleration time, checking the overvoltage suppression function during deceleration, and evaluating whether a braking resistor is required if the application demands rapid stopping.

5. Practical Example of Acceleration and Deceleration Time Configuration​

Suppose a factory uses a Yaskawa V1000 inverter to control an industrial fan motor with a maximum frequency of 50 Hz.
The operating requirements are:

• Acceleration time: 15 seconds.
• Deceleration time: 25 seconds.
• Maximum frequency: 50 Hz.

The parameters should be configured as follows:

Parameter	Setting	Description
E1-04	50 Hz	Maximum frequency
C1-01	15.0 s	Acceleration time
C1-02	25.0 s	Deceleration time

With this configuration, when the inverter receives a RUN command, it will increase the output frequency from 0 Hz to 50 Hz over approximately 15 seconds according to the acceleration profile. When a stop command is received using the deceleration stop method, the inverter will reduce the output frequency from 50 Hz to 0 Hz over approximately 25 seconds according to the deceleration profile.

These values are for illustration purposes only. In actual applications, technicians must select appropriate settings based on load inertia, motor power, process requirements, and the braking capability of the system.

6. Using the S-Curve Function to Reduce Mechanical Vibration​

In addition to configuring acceleration and deceleration times, the Yaskawa V1000 also supports the S-curve function through parameter group C2.
The main parameters include:

• C2-01: S-curve time at the beginning of acceleration.
• C2-02: S-curve time at the end of acceleration.
• C2-03: S-curve time at the beginning of deceleration.
• C2-04: S-curve time at the end of deceleration.

This function makes speed changes smoother by reducing sudden changes in acceleration and minimizing mechanical stress on the system. For example, in product conveyor applications, using the S-curve function can help prevent products from shifting when the conveyor starts or stops.

However, it is important to note that S-curve settings increase the actual acceleration and deceleration times. According to Yaskawa technical documentation, the actual times can be approximately calculated as follows:

• Actual acceleration time = C1-01 + (C2-01 + C2-02)/2.
• Actual deceleration time = C1-02 + (C2-03 + C2-04)/2.

Therefore, when precise operating times are required, technicians must take the effects of S-curve parameters into account.

7. Common Problems When Setting Acceleration and Deceleration Times​

During Yaskawa V1000 inverter configuration, several problems may occur if acceleration and deceleration times are not suitable for the load characteristics.
Overcurrent Fault During Acceleration (OC)

Possible causes include an acceleration time that is too short, a mechanically jammed load, or excessive torque requirements during motor startup. Check the motor current and actual load conditions, then adjust C1-01 accordingly.

Overvoltage Fault During Deceleration (OV)
This fault commonly occurs when the motor has high inertia and the deceleration time is too short. Check C1-02, regenerative energy conditions, and the appropriate braking solution.

Motor Stops Too Slowly

This may be caused by an excessively long C1-02 setting, S-curve parameters that increase the deceleration time, or the activation of overvoltage suppression functions.
Motor Does Not Accelerate Within the Configured Time
Check which acceleration time setting is currently selected. If digital inputs have been configured to switch between acceleration and deceleration time settings, the inverter may be using C1-03 through C1-08 instead of C1-01 and C1-02.

When a Yaskawa inverter fault occurs, operators should record the fault code and check the load condition, motor current, and DC bus voltage before changing any parameters. Repeatedly resetting the inverter without identifying the root cause should be avoided.

8. Important Considerations Before Operating the Inverter​

To achieve effective Yaskawa V1000 inverter configuration, keep the following points in mind:

• Check the motor specifications before setting acceleration and deceleration times.
• Avoid setting excessively short acceleration times when operating high-inertia loads.
• Do not apply abrupt deceleration if the system does not have an appropriate solution for handling regenerative energy.
• Check the stopping method configured in parameter b1-03. Ramp to Stop (b1-03 = 0) uses the deceleration ramp, while Coast to Stop (b1-03 = 1) allows the motor to stop through natural inertia.
• Check stall prevention functions during acceleration and deceleration, as they may cause actual operating times to exceed the configured values.
• Perform an initial no-load test before testing the system under actual load conditions.
• Save the parameter configuration for easier maintenance and troubleshooting.

Conclusion​

Setting acceleration and deceleration times is an important step when configuring a Yaskawa V1000 inverter. Parameters C1-01 and C1-02 help control motor speed changes, prevent sudden increases in current, and reduce mechanical stress during machine stopping.

In addition, combining these settings with parameter group C2 to configure the S-curve function can help the system operate more smoothly, particularly in applications that require high operating stability.

By following the correct Yaskawa V1000 inverter setup instructions, checking motor specifications, and selecting appropriate acceleration and deceleration times based on load characteristics, businesses can minimize equipment failures, extend equipment service life, and maintain stable operation throughout their automated production lines.