Adjusting the output torque (current) of the motor
4.6.2
Adjusting the S-PM geared motor starting torque (Pr.785)
When a S-PM geared motor is used, reduction of the motor torque in the low-speed range (lower than 300 r/min) can
be improved.
Parameter
number
785
PM control torque boost
The above parameters can be set when Pr.160 Extended function display selection = "0". (Refer to page 182)
The above parameters are available with S-PM geared motors.
...... Specifications differ according to the date assembled. Refer to page 316 to check the SERIAL number.
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.
Drive unit model
FR-E720EX-0.2K to 1.5K
FR-E720EX-2.2K, 3.7K
In the low speed range of 300r/min or less, Pr. 22 Torque limit 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.
NOTE
Keep the short-time torque to Pr. 785 setting or lower.
114
Name
Initial value
S-PM motor capacity
0.1kW to 0.75kW
1.5kW, 2.2kW
Setting range
0 to 150%
9999
9999
Pr.785 setting
80% or less
50% or less
Description
Set the maximum torque to be generated
in the low-speed range of 300r/min or
less.
Set as 100%