Mitsubishi Electric 800 Series Instruction Manual page 539

5.13.1 Manual torque boost
V/F V/F V/F
Voltage drop in the low-frequency range can be compensated, improving reduction of the motor torque in the low-speed range.
• Motor torque in the low-frequency range can be adjusted according to the load, increasing the motor torque at the start up.
• By using the RT signal, it is possible to switch between 2 types of torque boost.
Pr.
0 Torque boost
G000
46 Second torque boost
G010
*1 Initial value for the FR-F860-00027.
*2 Initial value for the FR-F860-00061 and FR-F860-00090.
*3 Initial value for the FR-F860-00170 or higher.
 Starting torque adjustment
• Assuming Pr.19 Base frequency voltage is 100%, set the output voltage at 0 Hz to Pr.0 (Pr.46, Pr.112) in percentage.
• Perform the adjustment of the parameter little by little (approximately 0.5%), and confirm the status of the motor each time.
The motor may overheat when the value is set too high. Do not use more than 10% as a guideline.
 Setting multiple torque boosts (RT signal, Pr.46)
• When changing the torque boost depending on the usage or when using single inverter switching between multiple motors,
use the second torque boost.
• Pr.46 Second torque boost will become enabled when the RT signal turns ON.
NOTE
• The RT signal acts as the second function selection signal and makes the other second functions valid. (Refer to
348.)
• The RT signal is assigned to the terminal RT in the initial status. Set "3" in any of Pr.178 to Pr.189 (Input terminal function
selection) to assign the RT signal to another terminal.
• Set a larger value when the distance between the inverter and the motor is long or when there is not enough motor torque
in the low-speed range. It may cause overcurrent trip when it is set too large.
• Setting for Pr.0 and Pr.46 becomes enabled only when the V/F control is selected.
• When the initial value is set in Pr.0, the Pr.0 setting is automatically changed by changing the Pr.71 Applied motor, Pr.81
Number of motor poles setting. (Refer to
• Changing the terminal assignment using Pr.178 to Pr.189 (Input terminal function selection) may affect the other
functions. Set parameters after confirming the function of each terminal.
Parameters referred to
Pr.3 Base frequency, Pr.19 Base frequency voltage
Pr.71 Applied motor
Pr.178 to Pr.182 (Input terminal function selection)
538
5. PARAMETERS
5.13 (G) Control parameters
Name Initial value
*1
3%
*2
2%
*3
1%
9999
Pr.0
Setting
Pr.46
range
page
page 351
Setting range
0 to 30% Set the output voltage at 0 Hz in %.
0 to 30% Set the torque boost value at when RT signal is ON.
9999 Without second torque boost
100%
Output
voltage
0 Output Base
frequency
frequency
(Hz)
351)
page 539
page 343
Description
page