Mitsubishi Electric 800 Series Instruction Manual (Function page 391

• When offline auto tuning ends, press the STOP/RESET key on the operation panel during PU operation. In the External
operation mode, turn OFF the start signal (STF signal or STR signal).
This operation resets the offline auto tuning, and the monitor display of the operation panel returns to normal.
(Without this operation, next operation cannot be started.)
NOTE
• The motor constants measured once during offline auto tuning are stored as parameters and their data are held until offline
auto tuning is performed again. However, the tuning data is cleared when performing All parameter clear.
• Changing Pr.71 (Pr.450) after tuning completion will change the motor constant. For example, if "3" is set in Pr.71 after tuning
is performed with Pr.71 = "0", the tuning data becomes invalid. To use the tuned data, set "0" again in Pr.71.
• If offline auto tuning has ended in error (see the following table), motor constants are not set. Perform an inverter reset and
restart tuning.
Error display
8 Forced end
9 Inverter protective function operation
91 The current limit (stall prevention) function is activated.
92 The converter output voltage fell to 75% of the rated voltage.
Calculation error.
93
The motor is not connected.
• When tuning is ended forcibly by pressing the STOP/RESET key or turning OFF the start signal (STF or STR) during
tuning, offline 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 detection, set "0" (motor overheat protection by
inverter invalid) in Pr.9 to protect the motor from overheating.
NOTE
• 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
performed.
• The set frequency monitor displayed during the offline auto tuning is 0 Hz.
CAUTION
• 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.
390
15. (C) Motor Constant Parameters
15.2 Offline auto tuning
Error cause Countermeasures
Set "1" in Pr.96 and retry.
Make the setting again.
Set the acceleration/deceleration time longer.
Set Pr.156 Stall prevention operation selection = "1".
Check for the power supply voltage fluctuation.
Check the Pr.83 Rated motor voltage setting.
Check the Pr.83 and Pr.84 settings.
Check the motor wiring and make the setting again.