80
V/F pattern
4.5.2
Load pattern selection (Pr. 14)
You can select the optimum output characteristic (V/F characteristic) for the application and load characteristics.
Parameter
Number
Name
Initial Value
Setting Range
Description
14
Load pattern selection
1
0
For constant-torque load
1
For variable-torque loads
The above parameters can be set when
Pr. 160 User group read selection
= "0".
(Refer to page 173)
(1) For constant-torque load (setting "0")
At or less than the base frequency voltage, the output voltage varies linearly with the
output frequency.
Set this value when driving the load whose load torque is constant if the speed varies,
e.g. conveyor, cart or roll drive.
(2) For variable-torque load (setting "1", initial value)
At or less than the base frequency voltage, the output voltage varies with the output
frequency in a square curve.
Set this value when driving the load whose load torque varies in proportion to the
square of the speed, e.g. fan or pump.
REMARKS
The RT signal is assigned to the terminal RT in the initial setting. By setting "3" in any of
Pr. 178 to Pr. 189 (input terminal function
selection)
, you can assign the RT signal to the other terminal.
i
Parameters referred to
i
Pr. 3 Base frequency
Refer to page 78
Pr. 178 to Pr. 189 (Input terminal function selection)
Refer to page 110
100%
Output voltage
Pr.3
Base frequency
Output frequency (Hz)
POINT
If the load is a fan or pump, select "For rated torque load (setting "0")" in any of the
following cases.
When a blower of large moment of inertia (J) is accelerated in a short time
For constant-torque load such as rotary pump or gear pump
When load torque increases at low speed, e.g. screw pump
100%
Output voltage
Pr.3 Base frequency
Output frequency (Hz)
Summary of Contents for F700
Page 327: ...318 MEMO ...
Page 340: ...331 MEMO ...
