Base frequency setting (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 described on the motor rating plate is "50 Hz" only, 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 output may be shut off due to overload.
A caution is required especially in case of Pr.14 Load pattern selection = "1" (variable torque load).
• When using the Mitsubishi Electric constant torque motor, set Pr.3 to 60 Hz.
Setting multiple base frequencies (Pr.47)
• To change the base frequency when using a single inverter switching between multiple motors, use Pr.47 Second V/F
• Pr.47 is enabled when the RT signal is ON.
• The RT signal is a second function selection signal which also enables other second functions. (Refer to
• The RT signal is assigned to terminal RT in the initial status. Set "3" in one of Pr.178 to Pr.189 (Input terminal function
selection) to assign the RT signal to another terminal.
Setting of base frequency voltage (Pr.19)
• Use Pr.19 Base frequency voltage to set the base voltage (for example, rated motor voltage).
• When it is set lower than the power supply voltage, maximum output voltage of the inverter will be the voltage set in Pr.19.
• Pr.19 can be used in the following cases.
(a) When regenerative driving (continuous regeneration, etc.) is performed frequently
Output voltage will get higher than the specification during the regenerative driving, which may cause overcurrent trip
(E.OC) by the increase in motor current.
(b) When the fluctuation of power supply voltage is high
When the power supply voltage exceeds the rated voltage of the motor, fluctuation of rotation speed or overheating
of motor may occur due to excessive torque or increase in motor current.
• When the Advanced magnetic flux vector control or PM motor control is selected, Pr.3, Pr.47, and Pr.19 will become disabled,
and Pr.83 and Pr.84 will become enabled.
However, S-pattern curve with Pr.29 Acceleration/deceleration pattern selection = "1" (S-pattern acceleration/deceleration
A) will make Pr.3 or Pr.47 enabled. (S-pattern curve under PM motor control is the rated frequency of the motor.)
• When Pr.71 Applied motor = "2" (adjustable 5 points V/F), setting for Pr.47 will become disabled. Also, Pr.19 cannot be set
to "8888" or "9999".
• 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.14 Load pattern
Pr.29 Acceleration/deceleration pattern
Pr.83 Rated motor voltage, Pr.84 Rated motor
Pr.178 to Pr.189 (Input terminal function
5.13 (G) Control parameters