• During execution of offline auto tuning, do not switch ON/OFF the Second function selection (RT) signal. Auto tuning will not
be performed properly.
• Setting offline auto tuning (Pr.96 Auto tuning setting/status = "1") will make pre-excitation invalid.
• Since the Inverter running (RUN) signal turns ON when tuning is started, caution is required especially when a sequence which
releases a mechanical brake by the RUN signal has been designed.
• When executing offline auto tuning, input the run command after switching ON the main circuit power (R/L1, S/L2, T/L3) of the
• During tuning, the monitor is displayed on the operation panel as follows.
Parameter unit (FR-LU08) display
(2) During tuning
• When offline auto tuning ends, press
the start signal (STF signal or STR signal).
This operation resets the offline auto tuning, and the PU's monitor display returns to the normal indication.
(Without this operation, next operation cannot be started.)
• 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 after tuning completion will change the motor constant.
• 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
The motor is not connected.
• 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
• For a motor with a PTC thermistor, thermal protector, or other thermal detector, set "0" (motor overheat protection by
inverter invalid) in
to protect the motor from overheating.
STF STOP PU
on the operation panel during PU operation. For External operation, turn OFF
or turning OFF the start signal (STF or STR) during tuning, offline auto
after tuning is complete.
Operation panel indication
Set "1" in Pr.96 and retry the tuning.
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.3 setting.
Check the Pr.3 and Pr.19 settings.
Check the motor wiring and make the setting again.
5.9 (C) Motor constant parameters