Check First When You Have Troubles; Motor Will Not Start; Motor Generates Abnormal Noise - Mitsubishi Electric FR-A720-0.4K Instruction Manual

Check first when you have troubles

5.5 Check first when you have troubles

When performing real sensorless vector control or vector control, refer to trouble shooting on
page 127 (torque control) and page 139 (position control) in addition to the following check points.
POINT
If the cause is still unknown after every check, it is recommended to initialize the parameters (initial value) then reset
the required parameter values and check again.

5.5.1 Motor will not start

1) Check the Pr.0 Torque boost setting if V/F control is exercised. (Refer to page 142)
2) Check the main circuit
Check that a proper power supply voltage is applied (operation panel display is provided).
Check that the motor is connected properly.
Check that the jumper across P/+-P1 is connected.
3) Check the input signals
Check that start signal is input.
Check that both the forward and reverse rotation start signals are not input simultaneously.
Check that the frequency setting signal is not zero. (When the frequency command is 0Hz and the
start command is entered, FWD or REV LED on the operation panel flickers.)
Check that the AU signal is on when terminal 4 is used for frequency setting.
Check that the output stop signal (MRS) or reset signal (RES) is not on.
Check that the CS signal is not OFF with automatic restart after instantaneous power failure function
is selected (Pr. 57 ≠ "9999").
Check that the sink or source jumper connector is fitted securely. (Refer to page 30)
Check that the encoder wiring is correct. (during encoder feedback control or vector control)
Check that the voltage/current input switch is correctly set for analog input signal (0 to 5V/0 to 10V, 4
to 20mA).
4) Check the parameter settings
Check that Pr. 78 Reverse rotation prevention selection is not selected.
Check that the Pr. 79 Operation mode selection setting is correct.
Check that the bias and gain (calibration parameter C2 to C7) settings are correct.
Check that the Pr. 13 Starting frequency setting is not greater than the running frequency.
Check that frequency settings of each running frequency (such as multi-speed operation) are not zero.
Check that especially the Pr. 1 Maximum frequency setting is not zero.
Check that the Pr. 15 Jog frequency setting is not lower than the Pr. 13 Starting frequency setting.
Check that the Pr. 359 Encoder rotation direction setting under encoder feed back control or vector
control is correct.
Set "1" in Pr. 359 if "REV" on the operation panel is on when the forward command is given.
5) Inspection of load
Check that the load is not too heavy.
Check that the shaft is not locked.

5.5.2 Motor generates abnormal noise

No carrier frequency noises (metallic noises) are generated.
Soft-PWM control to change the motor tone into an unoffending complex tone is factory-set to valid
by Pr. 72 PWM frequency selection.
Adjust Pr. 72 PWM frequency selection to change the motor tone.
Check that the gain value under real sensorless vector control or vector control is not too high. Check the
setting of Pr. 820 (Pr. 830) Speed control P gain when speed control is exercised and Pr. 824 (Pr. 834) Torque
control P gain when torque control is exercised.
Check for any mechanical looseness.
Contact the motor manufacturer.
402
page 108 (speed control),