Adjust The Output Torque Of The Motor (Current); Manual Torque Boost (Pr. 0, Pr. 46) - Mitsubishi Electric FR-F740-00023-EC Instruction Manual

3.2 Adjust the output torque of the motor (current)

Purpose
Set starting torque manually
Automatically control output current
according to load
Compensate for motor slip to secure
low-speed torque
Limit output current to prevent inverter
trip
Select overload according to application
Change the overload current rating
specifications
3.2.1

Manual torque boost (Pr. 0, Pr. 46)

You can compensate for a voltage drop in the low-frequency region to improve motor torque reduction in the low-
speed range.
Motor torque in the low-frequency range can be adjusted to the load to increase the starting motor torque.
The starting torque boost can be changed by switching terminals.
Parameter
Name
Number
0 Torque boost
Second torque
46
*1
boost
*1 They can be set when Pr. 160 User group read selection = "0". (Refer to page 146.)
100%
Output
voltage
Pr.0
Setting
Pr.46
range
0
(2) Set multiple torque boost (RT signal, Pr. 46)
⋅ Use the second torque boost when changing the torque boost according to application or when using multiple
motors by switching between them by one inverter.
⋅ Pr. 46 Second torque boost is made valid when the RT signal turns on.
REMARKS
⋅ The RT signal acts as the second function selection signal and makes the other second functions valid. (Refer to page 92)
⋅ The RT signal is assigned to the RT terminal in the default setting. By setting "3" to any of Pr. 178 to Pr. 189 (Input terminal function
selection), you can assign the RT signal to the other terminal.
CAUTION
⋅ Increase the setting when the distance between the inverter and motor is long or when motor torque is insufficient in the low-
speed range. If the setting is too large, an overcurrent trip may occur.
⋅ When simple magnetic flux vector control is selected in Pr. 80, the settings of Pr. 0 and Pr. 46 are invalid.
⋅ When using the inverter dedicated motor (constant torque motor) with the 00126 or 00170, set the torque boost value to 2%.If the
initial set Pr. 71 value is changed to the setting for use with a constant-torque motor, the Pr. 0 setting changes to the
corresponding value in above.
⋅ Changing the terminal assignment using Pr. 178 to Pr. 189 (input terminal function selection) may affect the other functions. Please
make setting after confirming the function of each terminal.
♦ Parameters referred to ♦
Pr. 3 Base frequency, Pr. 19 Base frequency voltage
Pr. 71 Applied motor Refer to page 85
Pr. 80 Motor capacity Refer to page 58
Pr. 178 to Pr. 189 (Input terminal function selection)
Manual torque boost
Simple magnetic flux
vector control
Slip compensation
Stall prevention operation
Load pattern selection
Multiple rating setting
Initial Value
00023
00038 to 00083
00126, 00170
00250 to 00770
00930, 01160
01800 or more
9999
(1) Starting torque adjustment
Output
Base
frequency
frequency
(Hz)
Refer to page 68
Refer to page 90

Adjust the output torque of the motor (current)

Parameter that must be Set
Pr. 0, Pr. 46
Pr. 71, Pr. 80, Pr. 90
Pr. 245 to Pr. 247
Pr. 22, Pr. 23, Pr. 66,
Pr. 154, Pr. 156, Pr. 157
Pr. 14
Pr. 570
Setting
Range
6%
4%
3%
0 to 30% Set the output voltage at 0Hz as %.
2%
1.5%
1%
Set the torque boost value when the
0 to 30%
RT signal is on.
9999 Without second torque boost
⋅ On the assumption that Pr. 19 Base frequency voltage is
100%, set the output voltage at 0Hz in % in Pr. 0 (Pr. 46).
⋅ Adjust the parameter little by little (about 0.5%), and check
the motor status each time. If the setting is too large, the
motor will overheat. The guideline is about 10% at the
greatest.
Refer to Page
57
58
59
60
70
65
Description
57
Pr. 1
page 66
Pr.45
page 79
Pr.47
page 68
3