Mitsubishi Electric FR-A700 Instruction Manual page 354

Set V/f pattern
Base frequency voltage setting (Pr. 19)
Use Pr. 19 "Base frequency voltage" to set the base voltage (e.g. rated motor voltage). If the set-
ting is less than the power supply voltage, the maximum output voltage of the inverter is as set
in Pr. 19.
Pr. 19 can be utilized in the following cases:
● When regeneration frequency is high (e.g. continuous regeneration)
During regeneration, the output voltage becomes higher than the reference and may cause
an over current trip (E.OC ) due to an increased motor current.
● When power supply voltage variation is large
When the power supply voltage exceeds the rated voltage of the motor, speed variation or
motor overheat may be caused by excessive torque or increased motor current.
● For special settings (87Hz function, special motors, field weakening range).
Pr. 19 can also be set to a value above the power supply voltage when operating motors
with special windings, in 87Hz mode or for field weakening operation with a specific output
voltage. The inverter will then use a V/f pattern the rise of which is defined by Pr. 3 and
Pr. 19. However, the actual effective output voltage cannot be higher than the power supply
voltage and is thus limited to this maximum value.
NOTES
When operation is discontinued under vector control due to failure of an encoder, etc., set-
ting "20" in Pr. 800 "Control method selection" enables V/f control operation.
When advanced magnetic flux vector control mode, real sensorless vector control or vector
control is selected, Pr. 3, Pr. 47, Pr. 113 and Pr. 19 are made invalid and Pr. 83 and Pr. 84
are made valid.
Note that Pr. 3 or Pr. 47 and Pr. 113 values are made valid as inflection points of S-pattern
when Pr. 29 "Acceleration/deceleration
pattern selection" = 1 (S-pattern acceleration/deceleration A).
When Pr. 71 "Applied motor" is set to 2 (adjustable 5 points V/f characteristic), the Pr. 47
and Pr. 113 setting becomes invalid. In addition, you cannot set "8888" or "9999" in Pr. 19.
Changing the terminal assignment using Pr. 178 to Pr. 189 "Input terminal function selec-
tion" may affect the other functions. Make setting after confirming the function of each termi-
nal.
Note that the output voltage of the inverter cannot exceed the power supply voltage.
6 - 174
Parameter