Base frequency, voltage
Use this function to adjust the inverter outputs (voltage, frequency) to match with the motor rating.
Setting of base frequency (Pr. 3)
● When operating a standard motor, generally set the rated frequency of the motor in Pr. 3 "Base
frequency". When the motor operation require switching to the commercial power supply, set the
power supply frequency in Pr. 3.
● When the frequency on the motor rating plate is only "50 Hz", make sure to set to "50 Hz". When
it is set to "60 Hz", the voltage will drop too much, causing insufficient torque. As a result, the
inverter may trip due to overload.
A caution is required especially in case of Pr. 14 "Load pattern selection" = "1" (variable torque
● When using the Mitsubishi constant torque motor, set Pr. 3 to 60 Hz.
Setting multiple base frequencies (Pr. 47)
● To change the base frequency when using single inverter switching between multiple motors,
use Pr. 47 "Second V/F (base frequency)".
● Pr. 47 will become enabled when the RT signal turns ON.
The RT signal acts as the second function selection signal and makes the other second functions
valid. (Refer to page 5-291.)
The RT signal is assigned to the terminal RT in the initial status. It is also possible to assign the RT
signal to other terminal by setting "3" on Pr. 178 to Pr. 189 (input terminal function selection).
60 Hz 50 Hz
Base frequency voltage
Set the frequency at the rated motor torque.
0 to 590 Hz
(50 Hz/60 Hz)
0 to 1000 V
Set the base voltage.
95% of the power supply voltage
Same as the power supply voltage
0 to 590 Hz
Set the base frequency at the RT signal ON.
Second V/F disabled
Output voltage related to the output frequency
(G) Control parameters
5 - 537