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Check First When You Have Troubles; Motor Does Not Start; Motor Generates Abnormal Noise; Motor Generates Heat Abnormally - Mitsubishi Electric FR-B-750 to 75K Instruction Manual

Fr-b-750 to 75k (200v class), fr-b-750 to 110k (400v class).
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5.5 Check first when you have troubles

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 does not start

1) 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.
2) 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 signal.
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 29)
Check that the voltage/current input switch is correctly set for analog input signal (0 to 5V/0 to 10V, 4
to 20mA).
3) 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 is correct during the encoder feedback control.
When "REV" is lit on the operation panel under the forward rotation command, set "1" in Pr.359.
4) 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

Check for any mechanical looseness.
Contact the customer support of the motor manufacturer.

5.5.3 Motor generates heat abnormally

Is the fan for the motor is running? (Check for accumulated dust.)
Check that the load is not too heavy. Lighten the load.
Check that the inverter output voltages (U, V, W) balanced.
Was the motor type set? Check the setting of Pr. 71 Applied motor.
When using any FR-B3 series, perform offline auto tuning. (Refer to page 70.)

5.5.4 Motor rotates in opposite direction

Check that the phase sequence of output terminals U, V and W is correct.
Check that the start signals (forward rotation, reverse rotation) are connected properly. (Refer to page 26)
Check first when you have troubles


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