Mitsubishi Electric FR-A720-0.4K Instruction Manual page 426

Operation Panel
E.OSD
Indication
Name
Speed deviation excess detection
Trips the inverter if the motor speed is increased or decreased under the influence of the load etc.
during vector control with Pr. 285 Excessive speed deviation detection frequency set and cannot be
Description
controlled in accordance with the speed command value.
This fault is not available in the initial status.
· Check that the values of Pr. 285 Excessive speed deviation detection frequency and Pr. 853 Speed deviation
time are correct.
Check point
· Check for sudden load change.
· Check that the number of encoder pulses does not differ from the actual number of encoder pulses.
· Set Pr. 285 Excessive speed deviation detection frequency and Pr. 853 Speed deviation time correctly.
Corrective action
· Keep load stable.
· Set the correct number of encoder pulses in Pr. 369 Number of encoder pulses.
Operation Panel
E.ECT
Indication
Name Signal loss detection
Trips the inverter when the encoder signal is shut off under orientation control, encoder feedback
Description
control or vector control.
This fault is not available in the initial status.
· Check for the encoder signal loss.
· Check that the encoder specifications are correct.
· Check for a loose connector.
Check point
· Check that the switch setting of FR-A7AP/FR-A7AL (option) is correct.
· Check that the power is supplied to the encoder. Or, check that the power is not supplied to the
encoder later than the inverter.
· Check that the voltage of the power supplied to the encoder is same as the encoder output voltage.
· Remedy the signal loss.
· Use an encoder that meets the specifications.
· Make connection securely.
· Make a switch setting of FR-A7AP/FR-A7AL (option) correctly. (Refer to page 34)
Corrective action · Supply the power to the encoder. Or supply the power to the encoder at the same time when the
power is supplied to the inverter.
If the power is supplied to the encoder after the inverter, check that the encoder signal is securely
sent and set "0" in Pr. 376.
· Make the voltage of the power supplied to the encoder the same as the encoder output voltage.
Operation Panel
E.OD
Indication
Name
Excessive position fault
Trips the inverter when the difference between the position command and position feedback exceeds
Description
Pr. 427 Excessive level error under position control.
This fault is not available in the initial status.
· Check that the position detecting encoder mounting orientation matches the parameter.
Check point · Check that the load is not large.
· Check that the Pr. 427 Excessive level error and Pr. 369 Number of encoder pulses are correct.
· Check the parameters.
Corrective action · Reduce the load weight.
· Set the Pr. 427 Excessive level error and Pr. 369 Number of encoder pulses correctly.
Operation Panel
E.EP
Indication
Name
Encoder phase fault
Trips the inverter when the rotation command of the inverter differs from the actual motor rotation
Description
direction detected from the encoder.
This fault is not available in the initial status.
· Check for mis-wiring of the encoder cable.
Check point
· Check for wrong setting of Pr. 359 Encoder rotation direction.
· Perform connection and wiring securely.
Corrective action
· Change the Pr. 359 Encoder rotation direction value.
Causes and corrective actions
FR-PU04
E.OSd
FR-PU07
FR-PU04
E.ECT
FR-PU07
Fault 14
FR-PU04
FR-PU07
E.Od
FR-PU04 Fault 14
FR-PU07 E.EP
5
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