Mitsubishi Electronics FR-D720-008 ユーザーズマニュアル

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Adjust the output torque (current) of the motor
4.3 Adjust the output torque (current) of the motor
4.3.1
Manual torque boost (Pr. 0, Pr. 46)
(1) Starting torque adjustment
On the assumption that Pr. 19 Base frequency voltage is 100%, set
the output voltage at 0Hz in % to 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.
(2) Set two kinds of torque boosts (RT signal, Pr. 46
When you want to change torque boost according to applications, switch multiple motors with one inverter, etc., use Second
torque boost.
Pr. 46 Second torque boost is valid when the RT signal is on.
For the terminal used for RT signal input, set "3" in any of Pr. 178 to Pr. 182 (input terminal function selection) to assign the function.
Purpose
Parameter that should be Set
Refer to Page
Set starting torque manually
Manual torque boost
Pr. 0, Pr. 46
Automatically control output current 
according to load
General-purpose magnetic 
flux vector control
Pr. 71, Pr. 80
Compensate for motor slip to secure 
low-speed torque
Slip compensation 
Pr. 245 to Pr. 247
Limit output current to prevent 
inverter trip
Stall prevention operation
Pr. 22, Pr. 23, Pr. 66, Pr. 156, 
Pr. 157
Motor torque reduction in the low-speed range can be improved by compensating a voltage drop in the low-frequency range.
Motor torque in the low-frequency range can be adjusted to the load to increase the starting motor torque.
Two kinds of start torque boosts can be changed by switching between terminals.
Parameter 
Number
Name
Initial Value
Setting 
Range
Description
0
Torque boost
FR-D720-042 or less
FR-D740-022 or less
FR-D720S-008 to 042
6%
0 to 30%
Set the output voltage at 0Hz as %.
FR-D720-070 to 165
FR-D740-036 to 080
FR-D720S-070 and 100
4%
FR-D720-238 and 318
FR-D740-120 and 160
3%
46 
Second torque 
boost
9999
0 to 30%
Set the torque boost when the RT signal is on.
9999
Without second torque boost
* The above parameters can be set when Pr. 160 Extended function display selection = "0". (Refer to page 162)
REMARKS
The RT signal acts as the second function selection signal and makes the other second functions valid. (Refer to page 116)
V/F
V/F
V/F
Output voltage
Pr. 0
Pr. 46 Setting range
Base frequency
0
100%
Output frequency (Hz)