Mitsubishi Electric FR-A820-00046 Instruction Manual page 896

(G) Control parameters
Application for variable-torque load (Pr. 14 = "1")
● The output voltage will change in square curve against the output frequency at the base frequen-
cy or lower. (1.75th-power curve for FR-A820-01870(37K) or higher, and FR-A840-00930(37K) or
higher)
● Set this parameter when driving a load with load torque change proportionally against the square
of the rotation speed, such as fan and pump.
Vertical lift load applications (Pr. 14 = "2, 3")
● Set "2" when a vertical lift load is fixed as power driving load at forward rotation and regenerative
load at reverse rotation.
● Pr. 0 "Torque boost" is valid during forward rotation, and torque boost is automatically changed
to "0%" during reverse rotation.
● Set "3" for an elevated load that is in the driving mode during reverse rotation and in the
regenerative load mode during forward rotation according to the load weight, e.g. counterweight
system.
Fig. 5-343:
NOTE When torque is continuously regenerated as vertical lift load, it is effective to set the rated voltage
in Pr. 19 "Base frequency voltage" to prevent trip due to current at regeneration.
5 - 694
100%
Pr. 3 Base frequency
Output frequency (Hz)
Pr. 14 = 2
For vertical lift loads
At forward rotation boost ... Pr. 0 setting
At reverse rotation boost ... 0 %
Forward
rotation
Reverse
Pr. 0
rotation
Base frequency
Output frequency [Hz]
Characteristic with manual torque boost
Fig. 5-342:
Variable-torque load
Pr. 14 = 3
For vertical lift loads
At forward rotation boost ... 0 %
At reverse rotation boost ... Pr. 0 setting
Reverse
rotation
Pr. 0
Output frequency [Hz]
Parameters
I002751E
Forward
rotation
Base frequency
I001547E