Mitsubishi Electric FR-A720-0.4K Instruction Manual page 156

Operation Panel
E.RET
Indication
Name Retry count excess
If operation cannot be resumed properly within the number of retries set, this function trips the inverter.
Description
This function is available only when Pr. 67 Number of retries at fault occurrence is set. When the initial value
(Pr. 67 = "0") is set, this fault does not occur.
Check point
Find the cause of alarm occurrence.
Corrective action
Eliminate the cause of the error preceding this error indication.
E. 5
E. 6
Operation Panel
Indication
E. 7
E.CPU
Name
CPU fault
Description
Stops the inverter output if the communication error of the built-in CPU occurs.
Check point
Check for devices producing excess electrical noises around the inverter.
· Take measures against noises if there are devices producing excess electrical noises around the
Corrective action
inverter.
· Please contact your sales representative.
Operation Panel
E.CTE
Indication
Name Operation panel power supply short circuit, RS-485 terminal power supply short circuit
When the operation panel power supply (PU connector) is shorted, this function shuts off the power
output and stops the inverter. At this time, the operation panel (parameter unit) cannot be used and
RS-485 communication from the PU connector cannot be made. When the internal power supply for
Description
RS-485 terminals are shorted, this function shuts off the power output.
At this time, communication from the RS-485 terminals cannot be made.
To reset, enter the RES signal or switch power OFF, then ON again.
· Check for a short circuit in the PU connector cable.
Check point
· Check that the RS-485 terminals are connected correctly.
· Check the PU and cable.
Corrective action
· Check the connection of the RS-485 terminals
Operation Panel
E.MB1 to 7
Indication
Name
Brake sequence fault
The inverter output is stopped when a sequence error occurs during use of the brake sequence
function (Pr. 278 to Pr. 285). This fault is not available in the initial status (brake sequence function is
Description
invalid). (Refer to Chapter 4 of
Check point Find the cause of alarm occurrence.
Corrective action
Check the set parameters and perform wiring properly.
Operation Panel
E.OS
Indication
Name
Overspeed occurrence
Trips the inverter when the motor speed exceeds the Pr. 374 Overspeed detection level during encoder
Description
feedback control Real sensorless vector control and vector control. This fault is not available in the
initial status.
· Check that the Pr. 374 Overspeed detection level value is correct.
Check point
· Check that the number of encoder pulses does not differ from the actual number of encoder pulses.
· Set the Pr. 374 Overspeed detection level value correctly.
Corrective action
· Set the correct number of encoder pulses in Pr. 369 Number of encoder pulses.
Causes and corrective actions
FR-PU04
Retry No Over
FR-PU07
Fault 5
Fault 6
FR-PU04
FR-PU07
Fault 7
CPU Fault
⎯⎯
FR-PU04
FR-PU07 E.CTE
⎯⎯
FR-PU04
to
FR-PU07 E.MB1 Fault to E.MB7 Fault
the Instruction Manual (Applied))
FR-PU04
E.OS
FR-PU07
4
149