Mitsubishi FR-D720-5.5K

116
Check first when you have a trouble
4.6.12 Speed does not accelerate
4.6.13 Unable to write parameter setting
Check
points
Possible Cause Countermeasures
Refer
to
page
Input
signal
Start command and frequency command are chattering.
Check if the start command and the frequency
command are correct.
—
The wiring length used for analog frequency command
is too long, and it is causing a voltage (current) drop.
Perform analog input bias/gain calibration.
Input signal lines are affected by external EMI.
Take countermeasures against EMI, such as using
shielded wires for input signal lines.
Parameter
Setting
Pr. 1, Pr. 2, Pr. 18, calibration parameter C2 to C7 settings
are improper.
Check the settings of Pr. 1 Maximum frequency and Pr. 2
Minimum frequency. If you want to run the motor at 120Hz
or higher, set Pr. 18 High speed maximum frequency.
75
Check the calibration parameter C2 to C7 settings. 86
Torque boost (Pr. 0, Pr. 46) setting is improper under V/F
control, so the stall prevention function is activated.
Increase/decrease Pr. 0 Torque boost setting value by
0.5% increments so that stall prevention does not occur.
44
V/F pattern is improper when V/F control is performed.
(Pr. 3, Pr. 14, Pr. 19)
Set rated frequency of the motor to Pr. 3 Base frequency.
Use Pr. 19 Base frequency voltage to set the base voltage
(e.g. rated motor voltage).
75
Change Pr. 14 Load pattern selection according to the load
characteristic.
76
Stall prevention function is activated due to a heavy
load.
Reduce the load weight. —
Set Pr. 22 Stall prevention operation level higher according
to the load. (Setting Pr. 22 too large may result in
frequent overcurrent trip (E.OC).)
77
Check the capacities of the inverter and the motor. —
Auto tuning is not performed under General-purpose
magnetic flux vector control.
Perform offline auto tuning. 50
During PID control, output frequency is automatically controlled to make measured value = set point.
Main
Circuit
Brake resistor is connected between terminal P/+ and
P1 by mistake.
Connect an optional brake transistor (MRS type, MYS
type, FR-ABR) between terminal P/+ and PR.
9
Check
points
Possible Cause Countermeasures
Refer
to
page
Input
signal
Operation is being performed (signal STF or STR is
ON).
Stop the operation.
When Pr. 77 = "0" (initial value), write is enabled only
during a stop.
83
Parameter
Setting
You are attempting to set the parameter in the External
operation mode.
Choose the PU operation mode.
Or, set Pr. 77 = "2" to enable parameter write regardless
of the operation mode.
83
Parameter is disabled by the Pr. 77 Parameter write
selection setting.
Check Pr. 77 Parameter write selection setting. 83
Key lock is activated by the Pr. 161 Frequency setting/key
lock operation selection setting.
Check Pr. 161 Frequency setting/key lock operation selection
setting.
88
Operation mode and a writing device do not
correspond.
Check Pr. 79, Pr. 338, Pr. 339, Pr. 551, and select an
operation mode suitable for the purpose.
47, 92