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n8-55: Motor to Load Inertia Ratio

No.

(Hex.)

Name

Description

Default

(Range)

n8-55

(056E)

Motor to Load Inertia Ratio

Sets the ratio between motor inertia and machine inertia.

0

(0 - 3)

Sets the ratio between motor inertia and machine inertia to adjust the ACR.

Adjust in the following situations.

  • If torque and speed response are unsatisfactory, gradually increase the setting from 0.

  • If the motor does not run smoothly, gradually increase the setting from 0.

  • If the motor stalls during run at constant speed, gradually increase the setting from 0.

  • If there is vibration or hunting, decrease the setting.

Note:

  • If the value too low, the drive will detect STPo [Motor Step-Out Detected].

  • If you use one motor or more than motor at low inertia and the value is too high, there can be vibration in the motor.

0
Below 1:10

Use this setting in these conditions:

  • The ratio between the motor inertia and machine inertia is less than 1:10

  • There are large current ripples

1
Between 1:10 and 1:30

Use this setting in these conditions:

  • The ratio between the motor inertia and machine inertia is approximately 1:10 to 1:30

  • Parameter n8-55 = 0 and the drive detects STPo because of an impact load or sudden acceleration/deceleration.

2
Between 1:30 and 1:50

Use this setting in these conditions:

  • The ratio between the motor inertia and machine inertia is approximately 1:30 to 1:50

  • Parameter n8-55 = 1 and the drive detects STPo because of an impact load or sudden acceleration/deceleration.

3
Beyond 1:50

Adjust this parameter in these conditions:

  • The ratio between the motor inertia and machine inertia is more than 1:50

  • Parameter n8-55 = 2 and the drive detects STPo because of an impact load or sudden acceleration/deceleration.