Mitsubishi Electric FR-F800 Series Instruction Manual page 555

5.13.3 Load pattern selection
V/F V/F V/F
Optimal output characteristics (V/F characteristics) for application or load characteristics can be selected.
Pr.
14
Load pattern selection
G003
*1 When the setting value is selected under V/F control, the operation is the same as the one for constant-torque load (Pr.14 = "0").
 Application for constant-torque load (Pr.14 = "0")
• The output voltage will change linearly against the output frequency at the base frequency or lower.
• Set this parameter when driving a load that has constant load torque even when the rotation speed is changed, such as
conveyor, dolly, or roll drive.
Select for constant-torque load (setting value "0") even for fan and pump in following cases.
• When accelerating a blower with large moment of inertia (J) in a short period of time.
• When it is a constant-torque load such as rotary pump or gear pump.
• When the load torque increases in low speed such as screw pump.
 Application for variable-torque load (Pr.14 = "1", initial value)
• The output voltage will change in square curve against the output frequency at the base frequency or lower. (1.75th-power
curve for FR-F820-01540(37K) or higher, and FR-F840-00770(37K) or higher)
• Set this parameter when driving a load with load torque change proportionally against the square of the rotation speed,
such as a fan or pump.
100%
NOTE
• Pr.14 will become enabled under V/F control.
Parameters referred to
Pr.0 Torque boostpage 551
Pr.3 Base frequencypage 552
Pr.178 to Pr.189 (Input terminal function
554
5. PARAMETERS
5.13 (G) Control parameters
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Name Initial value
1
Pr.14 = 0
100%
Pr. 3 Base frequency
Output frequency (Hz)
Pr.14 = 1
Pr. 3 Base frequency
Output frequency (Hz)
selection)page 373
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Setting
range
0 For constant-torque load
1 For variable-torque load
*1 Excitation current low-speed scaling factor (Refer to
12 to 15
Description
page 555.)