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Adjustment of the output torque (current) of the motor
4
PARAMETERS
4.4.2 Start torque adjustment (Pr. 785)
For Pr. 785, set the maximum torque to be generated in the low-speed range of 300r/min or less.
Set a large value to generate a large starting torque.
To operate continuously at a low speed of less than 300r/min, a current must flow regardless of load. Thus, motor overload
trip (E.THM) may occur with a certain operation period even if no load is applied.
To operate continuously at a low speed of less than 300r/min, set the following or lower values in Pr. 785.
In the low speed range of 300r/min or less, Pr. 22 Stall prevention operation level is disabled. Thus, a drive unit failure, such
as the overcurrent protection and the loss of synchronism detection, may occur when a torque equal to or larger than the
Pr. 785 setting is applied.
Use the following function to minimize the motor torque drop that occurs in the low-speed range of 300r/min or less.
Parameter
Number
Name Initial Value Setting Range Description
785 PM control torque boost
9999
0 to 150%
Set the maximum torque to be generated in
the low-speed range of 300r/min or less.
9999 Set as 100%
The above parameters can be set when Pr. 160 Extended function display selection = "0". (Refer to page 144)
Drive unit model
Dedicated PM
motor capacity
Pr.785 setting
FR-D720-0.2K to 1.5K-G 0.1kW to 0.75kW 80% or less
FR-D720-2.2K to 3.7K-G 1.5kW to 2.2kW 50% or less
NOTE
y Keep the short-time torque to Pr. 785 setting or lower.
