Mitsubishi Electronics FR-A700 Manual De Usuario

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.

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.

Check the calibration parameter C2 to C7 settings.

The maximum voltage (current) input value is not set 
during the external operation. (Pr.125, Pr.126, Pr.18)

Check the Pr.125 Terminal 2 frequency setting gain 
frequency and Pr.126 Terminal 4 frequency setting gain 
frequency settings. To operate at 120Hz or higher, set 
Pr.18 High speed maximum frequency.  

Torque boost (Pr. 0, Pr. 46, Pr. 112) 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.

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).

Change Pr. 14 Load pattern selection according to the load 
characteristic.

Stall prevention (torque limit) function is activated due to 
a heavy load.

Reduce the load weight.

—

Set Pr. 22 Stall prevention operation level  (Torque limit level) 
higher according to the load. (Setting Pr. 22 too large 
may result in frequent overcurrent trip (E.OC ).)

(100)

Check the capacities of the inverter and the motor.

—

Auto tuning is not performed under Advanced magnetic 
flux vector control, Real sensorless vector control, or 
vector control. 

Perform offline auto tuning.

The setting of pulse train input is improper.

Check the specification of the pulse generator (open 
collector output or complementary output) and check the 
adjustment of the pulse train and frequency (Pr. 385 and 
Pr. 386).

During PID control, output frequency is automatically controlled to make measured value = set point.

Brake resistor is connected across terminals P/+ and 
P1 or across P1 and PR by mistake. (22K or lower)

Remove the jumper across terminals PR and PX (7.5K 
or lower) and connect an option brake resistor (FR-ABR) 
across terminals P/+ and PR.

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.

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. 

Parameter is disabled by the Pr. 77 Parameter write 
selection setting.

Check Pr. 77 Parameter write selection setting.

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.

Operation mode and a writing device do not 
correspond.

Check Pr. 79, Pr. 338, Pr. 339, Pr. 550, Pr. 551, and select 
an operation mode suitable for the purpose. 

Wiring or installation is improper.

Check for the wiring and the installation.
Power lamp is lit when power is input to the control 
circuit (R1/L11, S1/L21).