Mitsubishi Electric FR-D720-008 Instruction Manual page 110

Selection and protection of a motor
3) When offline auto tuning ends, press
OFF the start signal (STF signal or STR signal) once.
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.)
4) If offline auto tuning ended in error (see the table below), motor constants are not set.
Perform an inverter reset and restart tuning.
Error
Display
8 Forced end
9 Inverter protective function operation
91 Current limit (stall prevention) function was activated.
92 Converter output voltage reached 75% of rated value.
Calculation error
93
A motor is not connected.
5) When tuning is ended forcibly by pressing
auto tuning does not end normally. (The motor constants have not been set.)
Perform an inverter reset and restart tuning.
6) When using the motor corresponding to the following specifications and conditions, reset Pr.9 Electronic thermal O/L
relay as below after tuning is completed.
a) When the rated power specifications of the motor is 200/220V(400/440V) 60Hz, set 1.1 times rated motor current
value in Pr.9.
b) When performing motor protection from overheat using a PTC thermistor or motor with temperature detector such
as Klixon, set "0" (motor overheat protection by the inverter is invalid) in Pr.9.
7) When you know motor excitation current (no load current), set the value in Pr. 82 Motor excitation current.
NOTE
The motor constants measured once in the offline auto tuning are stored as parameters, and their data are held until
the offline auto tuning is performed again.
An instantaneous power failure occurring during tuning will result in a tuning error.
After power is restored, the inverter goes into the normal operation mode. Therefore, when STF (STR) signal is ON,
the motor runs in the forward (reverse) rotation.
Any alarm occurring during tuning is handled as in the ordinary mode. Note that if a fault retry has been set, retry is
ignored.
As the motor may run slightly during offline auto tuning, fix the motor securely with a mechanical brake or make sure
that there will be no problem in safety if the motor runs. Note that if the motor runs slightly, tuning performance is
unaffected.
Parameters referred to
Pr. 9 Electronic thermal O/L relay
Pr. 71 Applied motor
Pr. 80 Motor capacity
Pr. 156 Stall prevention operation selection
Pr. 178 to Pr. 182 (input terminal function selection)
Pr. 190, Pr. 192 (output terminal function selection)
106
of the operation panel during PU operation. For external operation, turn
Error Cause
or turning OFF the start signal (STF or STR) during tuning, offline
CAUTION
Refer to page 98
Refer to page 98
Refer to page 73
Refer to page 77
Refer to page 111
Refer to page 117
Remedy
Set "11" in Pr. 96 and perform tuning again.
Make setting again.
Set "1" in Pr. 156.
Check for fluctuation of power supply voltage.
Check the motor wiring and make setting again.
Set the rated current of the motor in Pr. 9.