• If offline auto tuning has ended in error (see the following table), motor constants are not set. Perform an inverter reset and
perform tuning again.
Inverter protective function operation
The current limit (stall prevention) function is activated.
The converter output voltage fell to 75% of the rated voltage.
The motor is not connected.
Rotation tuning frequency setting error (The frequency command
for the tuning was given to exceed the maximum frequency setting,
or to be in the frequency jump range.)
• When tuning is ended forcibly by pressing
tuning does not end properly. (The motor constants have not been set.)
Perform an inverter reset and perform tuning again.
• When the rated power supply of the motor is 200/220 V (400/440 V) 60 Hz, set the rated motor current multiplied by 1.1 in
Pr.9 Electronic thermal O/L relay after tuning is complete.
• For a motor with a PTC thermistor, thermal protector, or other thermal detector, set "0" (motor overheat protection by
inverter invalid) in Pr.9 to protect the motor from overheating.
• An instantaneous power failure occurring during tuning will result in a tuning error. After power is restored, the inverter starts
normal operation. Therefore, when the STF (STR) signal is ON, the motor starts forward (reverse) rotation.
• Any fault occurring during tuning is handled as in the normal operation. However, if the retry function is set, no retry is
• The set frequency monitor displayed during the offline auto tuning is 0 Hz.
• Note that the motor may start running suddenly.
• For performing offline auto tuning with the motor rotating in vertical lift applications, etc., caution is required to avoid falling
due to insufficient torque.
Changing the motor constants
• The motor constants can be set directly when the motor constants are known in advance, or by using the data measured
during offline auto tuning.
• According to the Pr.71 (Pr.450) setting, the range of the motor constant parameter setting values and units can be
changed. The changed settings are stored in the EEPROM as the motor constant parameters.
Changing the motor constants (when setting the Pr.92 and Pr.93 motor
constants in units of mH)
• Set Pr.71 as follows.
Mitsubishi Electric standard motor
Mitsubishi Electric high-efficiency motor
Mitsubishi Electric constant-torque motor
Mitsubishi Electric high-performance energy-saving
or turning OFF the start signal (STF or STR) during tuning, offline auto
SF-JR 4P 1.5 kW or lower
Set Pr.96 = "1 or 101" and try again.
Make the setting again.
Set the acceleration/deceleration time longer.
Set Pr.156 Voltage reduction selection during
stall prevention operation = "1".
Check for the power supply voltage fluctuation.
Check the Pr.84 Rated motor frequency setting.
Check the Pr.83 and Pr.84 settings. Check the motor
wiring and make the setting again.
Check the Pr.1 Maximum frequency and Pr.31 to
Pr.36 Frequency jump settings.
0 (initial value)
5.10 (C) Motor constant parameters