Protective and Diagnostic Functions
Chapter 8-1
8-1 Protective and Diagnostic Functions
8-1-1 Fault Detection (Fatal Error)
The Inverter will detect the following faults if the Inverter or motor burns or the internal circuitry of the Inverter malfunctions. When the Inverter detects a fault, the fault code will be displayed on the Digital Operator, the fault contact output will operate, and the Inverter output will be shut off causing the motor to coast to a stop. The stopping method can be selected for some faults, and the selected stopping method will be used with these faults. If a fault has occurred, refer to the following table to identify and correct the cause of the fault. Use one of the following methods to reset the fault after restarting the
Inverter. If the operation command is being input, however, the reset signal will be ignored. Therefore, be sure to reset the fault with the operation command turned off.
• Turn on the fault reset signal. A multi-function input (n36 to n39) must be set to 5 (Fault Reset).
• Press the STOP/RESET Key on the Digital Operator.
• Turn the main circuit power supply off and then on again.
Fault Displays and Processing
Fault name and meaning
%c
Fault display
%U uU1
Probable cause and remedy
Overcurrent (OC)
The Inverter output current is as high as or higher than 200% of the rated output current.
• A short-circuit or ground fault has occurred and at the
Inverter output.
→ Check and correct the motor power cable.
• The V/f setting is incorrect.
→ Reduce the V/f set voltage.
• The motor capacity is too large for the Inverter.
→ Reduce the motor capacity to the maximum permissible motor capacity.
• The magnetic contactor on the output side of the Inverter has been opened and closed.
→ Rearrange the sequence so that the magnetic contactor will not open or close while the Inverter has current output.
Overvoltage (OV)
The main circuit DC voltage has reached the overvoltage detection level
(200-V models: 410 V DC min.;
400-V models: 820 V DC min.).
Main circuit undervoltage (UV1)
The main circuit DC voltage has reached the undervoltage detection level (200 V DC for the
3G3JV-A2 _ , 160 V DC for the
3G3JV-AB _ , and 400 V DC for the
3G3JV-A4 _ ).
• The output circuit of the Inverter is damaged.
→ Replace the Inverter.
• The deceleration time is too short.
→ Increase the deceleration time.
• The power supply voltage is too high.
→ Decrease the voltage so it will be within specifications.
• There is excessive regenerative energy due to overshooting at the time of acceleration.
→ Suppress the overshooting as much as possible.
• Power supply to the Inverter has phase loss, power input terminal screws are loose, or the power cable is disconnected.
→
Check the above and take necessary countermeasures.
• Incorrect power supply voltage
→
Make sure that the power supply voltage is within specifications.
• Momentary power interruption has occurred.
→
Use the momentary power interruption compensation
(Set n47 so that the Inverter restarts after power is restored)
→
Improve the power supply.
• The internal circuitry of the Inverter is damaged.
→
Change the Inverter.
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Fault display
%h
%l1
%l2
%l3 gf ef _
Fault name and meaning Probable cause and remedy
Radiation fin overheated (OH)
The temperature of the radiation fins of the Inverter has reached
110°C ± 10°C.
Motor overload (OL1)
The electric thermal relay actuated the motor overload protective function.
• The ambient temperature is too high.
→ Ventilate the Inverter or install a cooling unit.
• The load is excessive.
→ Reduce the load.
→ Decrease the Inverter capacity.
• The V/f setting is incorrect.
→ Reduce the V/f set voltage.
• The acceleration/deceleration time is too short.
→ Increase the acceleration/deceleration time.
• The ventilation is obstructed.
→ Change the location of the Inverter to meet the installation conditions.
• The cooling fan of the Inverter does not work.
→ Replace the cooling fan.
• The load is excessive.
→
Reduce the load.
→
Decrease the Inverter capacity.
• The V/f setting is incorrect.
→
Reduce the V/f set voltage.
• The value in n11 for maximum voltage frequency is low.
→
Check the motor nameplate and set n11 to the rated frequency.
• The acceleration/deceleration time is too short.
→
Increase the acceleration/deceleration time.
• The value in n32 for rated motor current is incorrect.
→
Check the motor nameplate and set n32 to the rated current.
• The Inverter is driving more than one motor.
→
Disable the motor overload detection function and install an electronic thermal relay for each of the motors. The motor overload detection function is disabled by setting n32 to 0.0 or n33 to 2.
Inverter overload (OL2)
The electronic thermal relay has actuated the Inverter overload protective function.
Overtorque detection (OL3)
There has been a current or torque the same as or greater than the setting in n60 for overtorque detection level and that in n61 for overtorque detection time. A fault has been detected with n59 for overtorque detection function selection set to 2 or 4.
Ground fault (GF)
The ground fault current at the output of the Inverter has exceeded the rated output current of the Inverter.
External fault _ (EF _ )
An external fault has been input from a multi-function input. A multifunction input 1, 2, 3, or 4 set to 3 or 4 has operated. The EF number indicates the number of the corresponding input (S2 to S5).
• The motor protective time setting in n34 is short.
→
Set n34 to 8 (the default value).
• The load is excessive.
→ Reduce the load.
• The V/f setting is incorrect.
→ Reduce the V/f set voltage.
• The acceleration/deceleration time is too short.
→ Increase the acceleration/deceleration time.
• The Inverter capacity is insufficient.
→ Use an Inverter model with a higher capacity.
• The mechanical system is locked or has a failure.
→ Check the mechanical system and correct the cause of overtorque.
• The parameter settings were incorrect.
→ Adjust the n60 and n61 parameters according to the mechanical system. Increase the set values in n60 and n61.
• A ground fault has occurred at the Inverter output.
→ Check the connections between the Inverter and motor and reset the fault after correcting its cause.
• An external fault was input from a multi-function input.
→ Remove the cause of the external fault.
• The sequence is incorrect.
→ Check and change the external fault input sequence including the input timing and NO or NC contact.
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Protective and Diagnostic Functions
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Fault display f00 f01 f04 f05 f07 ce stp
0ff
Fault name and meaning Probable cause and remedy
Digital Operator transmission fault 1 (F00)
An initial memory fault has been detected
Digital Operator transmission fault 2 (F01)
A ROM fault has been detected.
Initial memory fault (F04)
An error in the built-in EEPROM of the Inverter has been detected.
Analog-to-digital converter fault
(F05)
An analog-to-digital converter fault has been detected.
Digital Operator fault (F07)
An error in the built-in control circuit of the Digital Operator has been detected.
• The internal circuitry of the Inverter has a fault.
→ Turn the Inverter off and on.
→ Replace the Inverter if the same fault occurs again.
• The internal circuitry of the Inverter has a fault.
→ Turn the Inverter off and on.
→ Replace the Inverter if the same fault occurs again.
• The internal circuitry of the Inverter has a fault.
→ Initialize the Inverter with n01 set to 8 or 9 and turn the Inverter off and on.
→ Replace the Inverter if the same fault occurs again.
• The internal circuitry of the Inverter has a fault.
→ Turn the Inverter off and on.
→ Replace the Inverter if the same fault occurs again.
• The internal circuitry of the Digital Operator has a fault.
→
→
Turn the Digital Operator off and on.
Replace the Digital Operator if the same fault occurs again.
Communications time-over (CE)
Normal RS-422A/485 communications were not established within 2 s.
The Inverter will detect this error if n68 (RS-422A/485 communications time-over detection selection) is set to
0, 1, or 2.
• A short-circuit, ground fault, or disconnection has occurred on the communications line.
→
Check and correct the line.
• The termination resistance setting is incorrect.
→
Set the termination resistance of only the Inverter located at each end of the network to ON.
• Noise influence.
→
Do not wire the communications line along with power lines in the same conduit.
→
Use the twisted-pair shielded wire for the communications line, and ground it at the Master.
• Master’s program error.
→
Check and correct the program so that communications will be performed more than once every 2-s period.
Emergency stop (STP)
An emergency stop alarm is input to a multi-function input. (A multifunction input 1, 2, 3, or 4 set to 19 or 21 has operated.)
Power supply error
• Insufficient power supply voltage
• Control power supply fault
• Hardware fault
• Communications circuit damage.
→ If the same error is detected as a result of a self-diagnostic test, change the Inverter.
• An emergency stop alarm is input to a multi-function input.
→ Remove the cause of the fault.
• The sequence is incorrect.
→ Check and change the external fault input sequence including the input timing and NO or NC contact.
• No power supply is provided.
→ Check and correct the power supply wire and voltage.
• Terminal screws are loosened.
→ Check and tighten the terminal screws.
• The Inverter is damaged.
→ Replace the Inverter.
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8-1-2 Warning Detection (Nonfatal Error)
The warning detection is a type of Inverter protective function that does not operate the fault contact output and returns the Inverter to its original status once the cause of the error has been removed. The Digital Operator flashes and display the detail of the error. If a warning occurs, take appropriate countermeasures according to the table below.
Note Some warnings or some cases stop the operation of the Inverter as described in the table.
Warning Displays and Processing
Fault display uU
(flashing)
%U
(flashing)
%h
(flashing) cal
(flashing)
%l3
(flashing) ser
(flashing) bb
(flashing)
Warning name and Meaning
Main Circuit Undervoltage (UV)
The main circuit DC voltage has reached the undervoltage detection level
(200 V DC for the CIMR-J7AZ-2 _ ,
160 V DC for the CIMR-J7AZ-B _ , and
400 V DC for the CIMR-J7AZ-4 _ ).
Probable cause and remedy
• Power supply to the Inverter has phase loss, power input terminal screws are loose, or the power line is disconnected.
→ Check the above and take necessary countermeasures.
• Incorrect power supply voltage
→ Make sure that the power supply voltage is within specifications.
• The power supply voltage is too high.
→ Decrease the voltage so it will be within specifications.
Main Circuit Overvoltage
The main circuit DC voltage has reached the overvoltage detection level
(200-V models: 410 V DC min.;
400-V models: 820 V DC min.).
Radiation fin overheated (OH)
The temperature of the radiation fins of the
Inverter has reached 110°C ± 10°C.
Communications standby (CAL)
No normal DSR message has been received during RS-422A/4895 communications. The Inverter detects this warning only when RUN command selection (n02) is set to 2 or frequency reference selection (n03) is set to 6. Until the warning is reset, no input other than communications input will be ignored.
Overtorque detection (OL3)
There has been a current or torque the same as or greater than the setting in n60 for overtorque detection level and that in n61 for overtorque detection time. A fault has been detected with n59 for overtorque detection function selection set to 1 or 3.
Sequence error (SER)
A sequence change has been input while the Inverter is in operation. Local or remote selection is input while the Inverter is in operation.
Note The Inverter coasts to a stop.
External base block (bb)
The external base block command has been input.
Note The Inverter coasts to a stop.
• The ambient temperature is too high.
→ Ventilate the Inverter or install a cooling unit.
• A short-circuit, ground fault, or disconnection has occurred on the communications line.
→ Check and correct the line.
• The termination resistance setting is incorrect.
→ Set the termination resistance of only the Inverter located at each end of the network to ON.
• Master’s program error.
→ Check the start of communications and correct the program.
• Communications circuit damage.
→ If a CAL or CE error is detected as a result of a self-diagnostic test, change the Inverter.
• The mechanical system is locked or has a failure.
→ Check the mechanical system and correct the cause of overtorque.
• The parameter settings were incorrect.
→ Adjust the n60 and n61 parameters according to the mechanical system. Increase the set values in n60 and n61.
• A sequence error has occurred.
→ Check and adjust the local or remote selection sequence as multi-function input.
• The external base block command has been in-put as multi-function input.
→
Remove the cause of external base block input.
• The sequence is incorrect.
→
Check and change the external fault input sequence including the input timing and NO or NC contact.
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Fault display ef
(flashing) stp
(flashing) fRn
(flashing) ce
%p1
(flashing)
%p2
(flashing)
%p3
(flashing)
%p4
(flashing)
%p5
(flashing)
Warning name and Meaning
Forward- and reverse-rotation input (EF)
The forward and reverse commands are input to the control circuit terminals simultaneously for 0.5 s or more.
Note The Inverter stops according to the method set in n04.
Emergency stop (STP)
The Digital Operator stops operating. The
STOP/RESET Key on the Digital Operator is pressed while the Inverter is operating according to the forward or reverse command through the control circuit terminals.
Note The Inverter stops according to the method set in n04.
The emergency stop alarm signal is input as multi-function input. A multi-function input 1,
2, 3, or 4 set to 20 or 22 has been used.
Note The Inverter stops according to the method set in n04.
Cooling fan fault (FAN)
The cooling fan has been locked.
Probable cause and remedy
• A sequence error has occurred.
→ Check and adjust the local or remote selection sequence.
• The parameter setting was incorrect.
→
Turn off the forward or reverse command once, check that the n06 parameter setting for
STOP/RESET Key function selection, and restart the Inverter.
• An emergency stop alarm is input to a multi-function input.
→ Remove the cause of the fault.
• The sequence is incorrect.
→ Check and change the external fault input sequence including the input timing and NO or NC contact.
• The cooling fan wiring has a fault.
→ Turn off the Inverter, dismount the fan, and check and repair the wiring.
Communications time-over (CE)
Normal RS-422A/485 communications were not established within 2 s. The Inverter will detect this error if n68 (RS-422A/485 communications time-over detection selection) is set to 0, 1, or 2.
• The cooling fan in not in good condition.
→ Check and remove the foreign material or dust on the fan.
• The cooling fan is beyond repair.
→ Replace the fan.
• A short-circuit, ground fault, or disconnection has occurred on the communications line.
→ Check and correct the line.
• The termination resistance setting is incorrect.
→ Set the termination resistance of only the Inverter located at each end of the network to ON.
Operation error (OP _ )
(Parameter setting error)
• Noise influence.
→ Do not wire the communications line along with power lines in the same conduit.
→ Use the twisted-pair shielded wire for the communications line, and ground it at the Master.
• Master’s program error.
→ Check and correct the program so that communications will be performed more than once every 2-s period.
• Communications circuit damage.
→ If the same error is detected as a result of a self-diagnostic test, change the Inverter.
• The values in n36 through n39 for multi-function inputs
1 through 4 have been duplicated. .
→
Check and correct the values.
• The V/f pattern settings do not satisfy the following condition. n14 O n12 < n11 O n09
→ Check and correct the set value.
• The rated motor current set in n32 exceeds 150% of the rated output current of the Inverter.
→ Check and correct the value.
• The frequency reference upper limit set in n30 and the frequency reference lower limit set in n31 do not satisfy the following condition. n30 P n31
→ Check and correct the set values.
• The jump frequencies set n49, n50 do not satisfy the following condition. n49 P n50
→
Check and correct the set values.
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