Toshiba AS1 Drives

Fault Code and MeaningCause and Remedy
OC1, OC1P
Overcurrent during acceleration

Cause:
The acceleration time (acc) is too short; V/f setting is improper; Restart signal input to rotating motor; Special motor used; Manual torque boost (vb) is large.



Remedy:

  • Increase the acceleration time (acc).

  • Check the V/f parameter setting.

  • Use UuS (Auto-restart) and UuC (Regenerative power ride-through control).

  • Increase the carrier frequency (CF).

  • Decrease torque boost (vb) setting value.

  • Decrease F601 (stall prevention level) to 130 as a guide.

  • Increase CF (carrier frequency) setting value if it is set at lower value (2kHz or less).


OC2, OC2P
Overcurrent during deceleration

Cause:
The deceleration time (dec) is too short.



Remedy:

  • Increase the deceleration time (dec).


OC3, OC3P
Overcurrent during fixed speed

Cause:
The load fluctuates abruptly; The load is in an abnormal condition.



Remedy:

  • Reduce the load fluctuation.

  • Check the load (operated machine).


OC1P, OC2P, OC3P (Note)
Component Failure / Overheat

Cause:
A main circuit element is defective; Overheat protection is activated.



Remedy:

  • Make a service call.

  • Check operation of cooling fan.

  • Check cooling fan control mode parameter F620.


OCA1
U-phase arm short-circuit

Cause:
A main circuit element is defective (U-phase).



Remedy:

  • Make a service call.


OCA2
V-phase arm short-circuit

Cause:
A main circuit element is defective (V-phase).



Remedy:

  • Make a service call.


OCA3
W-phase arm short-circuit

Cause:
A main circuit element is defective (W-phase).



Remedy:

  • Make a service call.


OCL
Loaded side overcurrent at start time

Cause:
Insulation of output main circuit or motor is defective; Motor has too small impedance; Drive circuit board damaged.



Remedy:

  • Check the cables and wires for defective insulation.

  • Selection of short circuit detection at starting parameter F613.

  • If this error appears when motor is not connected, the inverter may be faulty; make a service call.


OCr
Dynamic braking element overcurrent (110kW or larger)

Cause:
PB-PC/+ circuit is shorted; Resistor with resistance smaller than minimum allowable is connected; Parameter Pb set to 1 or 2 without connecting brake.



Remedy:

  • Check the impedance wiring for the resistor, etc.

  • Make a service call.

  • Check if regenerative brake is connected.

  • If regenerative brake is not necessary, set parameter Pb to 0.


OH
Overheating

Cause:
Cooling fan does not rotate; Ambient temperature too high; Vent blocked; Heat generating device nearby; Thermistor disconnected.



Remedy:

  • Restart operation by resetting inverter after it has cooled down.

  • The fan requires replacement if it does not rotate.

  • Secure sufficient space around the inverter.

  • Do not place any heat generating device near the inverter.

  • Make a service call.


OH2
Thermal trip stop command from external device

Cause:
Input signal impressed at control input terminal PTG; Thermal trip command (input function 46 or 47) issued by external device.



Remedy:

  • The motor is overheated, check whether the current flowing into the motor exceeds the rated current.


OL1
Inverter overload

Cause:
Rapid acceleration; DC braking amount too large; V/f setting improper; Restart signal input to rotating motor; Load too large.



Remedy:

  • Increase the acceleration time (acc).

  • Reduce the DC braking amount F251 and the DC braking time F252.

  • Check the V/f parameter setting.

  • Use UuS (Auto-restart) and UuC (Regenerative power ride-through control).

  • Use an inverter with a larger rating.


OL2
Motor overload

Cause:
V/f parameter improperly set; Motor is locked up; Low-speed operation performed continuously; Excessive load applied.



Remedy:

  • Check the V/f parameter setting.

  • Check the load (operated machine).

  • Check the OLM setting and adjust F606 according to sustainable overload in low-speed range.

  • Reduce the DC braking amount F251 and the DC braking time F252.


OLr
Dynamic braking resistor overload

Cause:
Rapid deceleration is operated; Dynamic braking is too large.



Remedy:

  • Increase the deceleration time (dec).

  • Increase the capacity of dynamic braking resistor (wattage) and adjust PBR capacity parameter Pbr.


OP1
Overvoltage during acceleration

Cause:
Input voltage fluctuates abnormally (Power supply > 500kVA, capacitor opened/closed, thyrister connected); Restart signal input to rotating motor.



Remedy:

  • Insert a suitable input reactor.

  • Use UuS (Auto-restart) and UuC (Regenerative power ride-through control).


OP2
Overvoltage during deceleration

Cause:
Deceleration time (dec) too short; Dynamic braking resistor has large resistance; Pb is OFF; Overvoltage limit F305 is OFF; Input voltage fluctuates.



Remedy:

  • Increase the deceleration time (dec).

  • Install a dynamic braking resistor.

  • Decrease dynamic braking resistance (Also reset the Pbr).

  • Set dynamic braking mode parameter Pb properly.

  • Set overvoltage limit operation F305 properly.

  • Insert a suitable input reactor.


OP3
Overvoltage during fixed speed operation

Cause:
Input voltage fluctuates abnormally; Motor is in regenerative state (load pushes motor).



Remedy:

  • Insert a suitable input reactor.

  • Install a dynamic braking resistor.


Ot
Overtorque

Cause:
Overtorque reaches detection level; Stall prevention performed longer than time set with F452.



Remedy:

  • Check system error.

  • Check whether the motor is overloaded or the brake is engaged.


UC
Low current operation

Cause:
Output current decreased to low-current detection level during operation.



Remedy:

  • Check the suitable detection level for the system (F611).

  • Make a service call if the setting is correct.


UP1
Undervoltage (main circuit)

Cause:
Input voltage too low; Momentary power failure occurs longer than detection time F628.



Remedy:

  • Check the input voltage.

  • To cope with momentary stop, enable UuC (Regenerative ride-through), UuS (auto-restart), and F628.


E
Emergency stop

Cause:
Inverter stopped by panel during auto/remote; Stop command (terminal function 20 or 21) issued by external device.



Remedy:

  • Reset the inverter.


EEP1
EEPROM error

Cause:
A data writing error occurs.



Remedy:

  • Turn off the inverter, then turn it on again. If it does not recover, make a service call.


EEP2
Initial read error

Cause:
Some internal data is corrupted; Power was turned off while typ was being set.



Remedy:

  • Make a service call.

  • Set typ again. If error persists, make a service call.


EEP3
Initial read error

Cause:
Some internal data is corrupted.



Remedy:

  • Make a service call.


EF1, EF2
Ground fault

Cause:
A current leaked from an output cable or the motor to ground.



Remedy:

  • Check the cable and the motor for ground faults.


EPH0
Output phase failure

Cause:
A phase failure occurred in the output line of the main circuit.



Remedy:

  • Check the main circuit output line, motor, etc. for phase failure.

  • Select output phase failure detection parameter F605.


EPH1
Input phase failure

Cause:
A phase failure occurred in the input line of the main circuit.



Remedy:

  • Check the main circuit input line for phase failure.


Err2
Main unit RAM fault

Cause:
The control RAM is defective.



Remedy:

  • Make a service call.


Err3
Main unit ROM fault

Cause:
The control ROM is defective.



Remedy:

  • Make a service call.


Err4
CPU fault

Cause:
The control CPU is defective.



Remedy:

  • Make a service call.


Err5
Communication time-out error

Cause:
Normal communication was not possible for the time set by F803.



Remedy:

  • Check the remote control device, cables, etc.


Err6
Gate array fault

Cause:
Main gate array is defective.



Remedy:

  • Make a service call.


Err7
Output current detector error

Cause:
The main output current detector is defective.



Remedy:

  • Make a service call.


Err8
Optional unit fault

Cause:
An optional device has failed (such as a communication device).



Remedy:

  • Check the connection of optional board(s).

  • Refer to instructions of options concerned.


Etn
Tuning error

Cause:
Motor capacity connected is 2 notches or more smaller than inverter; Motor is not 3-phase inductive; Tuning performed while motor running.



Remedy:

  • Make sure that a motor is connected.

  • Make sure that the motor is at standstill.

  • Perform auto-tuning 1 again and if error persists, perform tuning manually.


Etn1
Tuning detection error

Cause:
Some parameters (F410-F413) not detected; Motor capacity too small; Motor not 3-phase inductive; No motor connected; Cables too long (>30m); Motor running.



Remedy:

  • Make sure that a motor is connected.

  • Make sure that the motor is at standstill.

  • Perform auto-tuning 1 again and if error persists, perform tuning manually.


Etn2
Motor constant value error

Cause:
Some detection values (F410-F413) beyond limits; Motor capacity too small; Motor not 3-phase inductive; Cables too long (>30m); Motor running.



Remedy:

  • Make sure that the motor is at standstill.

  • Perform auto-tuning 1 again and if error persists, perform tuning manually.


Etn3
Motor constant setting error

Cause: Some items indicated on the motor nameplate are not entered correctly.

• Base frequency (uL)

• Base frequency voltage 1 (uLu)

• Motor rated capacity (F405)

• Motor rated current (F406)

• Motor rated speed (F407)



Remedy:

  • Make sure that all items on the motor nameplate are entered correctly.


Etyp
Inverter type error

Cause: Is circuit board (or main circuit/drive circuit board) replaced?



Remedy:

  • When board has been replaced, input 6 for typ.


E-10
Analog input terminal overvoltage

Cause: Overrated voltage is applied to analog input.



Remedy:

  • Apply voltage within the rated voltage.


E-11
Sequence error

Cause: The signal from system is not inputted into input terminals.

The input terminal function (130, 131) is not set up.

A value other than 0.0 is specified for F630, although the brake answer function is not used.



Remedy:

  • Please check if the sequence is normal or not.

  • Please set 130 or 131 as the input terminal to use.

  • Please set up 0.0, when you do not use system-supporting sequence.


E-12
Encoder error

Cause: Disconnection of encoder circuit.

The encoder is not connected correctly.



Remedy:

  • Check connection of encoder.

  • Connect encoder correctly.

  • Check whether the setting of F376 matches the phase-A and phase-B connections of the encoder.


E-13
Speed error (Over speed)

Cause: Encoder error (inverter error).



Remedy:

  • Check connection of encoder.

  • Connect encoder correctly.


E-17
Key failure alarm

Cause: The same key is input continuously more than 20 seconds.



Remedy:

  • Check the operation panel.


E-18
Terminal input error

Cause: Braking down of a wire for VI/II input signal.

Terminal circuit board comes off and falls.

P24 overcurrent.



Remedy:

  • Check VI/II input signal.

  • Install the control terminal board to the inverter.

  • Check P24 terminal short circuit to CC or CCA.


E-19
Abnormal CPU2 communication

Cause: An error arises during CPU2 communication.



Remedy:

  • Make a service call.


E-20
V/f control error

Cause: An internal control error occurs.



Remedy:

  • Make a service call.


E-21
CPU1 fault

Cause: A software error occurs in the control CPU.



Remedy:

  • Make a service call.


E-22
Abnormal logic input voltage

Cause: An abnormal voltage is applied to the control logic input terminal.



Remedy:

  • Check the signal given to the logic connected with the input terminal.


E-23
Option 1 error

Cause: Expansion I/O card 1 is defective.



Remedy:

  • Make a service call.


E-24
Option 2 error

Cause: Expansion I/O card 2 is defective.



Remedy:

  • Make a service call.


E-25
Stop position retaining error

Cause: A deviation error occurs during stop position retaining control.

The stop position adjustment range specified with F381 is too narrow.

Creeping speed is too fast.



Remedy:

  • Check connection of encoder.

  • Adjust the proportional P gain F362.

  • Increase F381.

  • Lower the creeping speed.


E-26
CPU2 fault

Cause: Motor control CPU is defective.

The drive circuit board in the inverter was damaged.



Remedy:

  • Make a service call.


E-29
Control power backup undervoltage error

Cause: The control voltage between +SU and CC terminals is too low.

Control power is not supplied through +SU and CC terminals.

The parameter F647 is not set correctly.



Remedy:

  • Check whether the voltage between +SU and CC terminals is DC20V or more.

  • Set F647 to 0 if a control power backup device is not connected to +SU and CC terminals.

  • To reset the inverter that has been tripped because of this error, turn it off and then back on.


SOut
Step-out (for PM motors only)

Cause: The motor shaft is locked.

One output phase is open.

An impact load is applied.



Remedy:

  • Unlock the motor shaft.

  • Check the interconnect cables between the inverter and the motor.


PrF
Power removal error

Cause: Error of power removal signal.



Remedy:

  • Make a service call.


OFF
ST signal OFF

Cause: ST terminal (terminal to which the ST function is assigned) is in open-circuit.



Remedy:

  • Close ST (terminal to which the ST function is assigned)-CC circuit.


PrA
PWR signal OFF

Cause: PWR terminal is in open-circuit.



Remedy:

  • Close PWR-P24/PLC circuit.


COFF
Control power backup undervoltage

Cause: The control voltage between +SU and CC terminals is too low.

Control power is not supplied through +SU and CC terminals.

The parameter F647 is not set correctly.



Remedy:

  • Check whether the voltage between +SU and CC terminals is DC20V or more.

  • Set F647 to 0 if a control power backup device is not connected to +SU and CC terminals.

  • Note: In the event of a COFF error, the inverter will not be reset automatically even if voltage returns. Turn off and back on to reset.


MOFF
Undervoltage in main circuit

Cause: The supply voltage between R, S and T is under voltage.

Trouble of rush current restraint circuit or DC circuit fuse.



Remedy:

  • Measure the main circuit supply voltage. If the voltage is at a normal level, the inverter requires repairing.

  • Make a service call.


rtry
Retry

Cause: The inverter is in the process of retry.

A momentary stop occurred.



Remedy:

  • The inverter is normal if it restarts after several tens of seconds.

  • The inverter restarts automatically. Be careful of the machine because it may suddenly restart.


Err1
Point setting alarm

Cause: The frequency setting signals at points 1 and 2 are set too close to each other.



Remedy:

  • Set the frequency setting signals at points 1 and 2 apart from each other.


CLr
Clear enabling indication

Cause: This message is displayed when pressing the STOP key while an error code is displayed.

Input terminal RES signal is ON during trip display.



Remedy:

  • Press the STOP key again to clear the trip.

  • Turn off the input terminal RES signal.


EOFF
Emergency stop enabling indication

Cause: The operation panel is used to stop the operation in automatic control or remote control mode.



Remedy:

  • Press the STOP key for an emergency stop. To cancel the emergency stop, press any other key.


HI / LO
Setting error alarm

Cause: An error is found in a setting when data is reading or writing.

(Error code and data displayed alternately).



Remedy:

  • Check whether the setting is made correctly.


db
DC braking

Cause: DC braking in process.



Remedy:

  • The message goes off in several tens of seconds if no problem occurs.


dbOn
Shaft fixing in control

Cause: Motor shaft fixing control is in process.



Remedy:

  • If the message disappears by stop command (ST-CC open), it is normal.


E1 / E2 / E3
Panel indication overflow

Cause: The digit number of the item displayed (e.g., frequency) is in excess of the specified digit number.



Remedy:

  • For indication of frequency, set multiplying rate (F702) lower. (Parameter setting that results in overflow is of course valid.)


init
Parameters in the process of initialization

Cause: Parameters are being initialized to default values.



Remedy:

  • Normal if the message disappears after a while (several seconds to several tens of seconds).


Atn
In auto-tuning 1

Cause: Auto-tuning 1 in process.



Remedy:

  • Normal if the message disappears after a few seconds (6900PL or less) or 2-3 minutes (6110KPC or larger).


LStp
Auto-stop because of continuous operation at lower-limit

Cause: The automatic stop function of F256 is being performed.



Remedy:

  • This function is deactivated when the command frequency becomes 0.2Hz or more higher than the lower-limit frequency (LL) or when a command for stopping operation is entered.


StOP
Momentary power failure slowdown stop

Cause: The deceleration stop function of uuc (regenerative power ride-through control) is activated.



Remedy:

  • To restart operation, reset the inverter or input an operation signal again.


HEAd / End
Display of first/last data items

Cause: First and last data in the AuH group.



Remedy:

  • To exit from the group, press the MODE key.


tun
During learning

Cause: Learning for brake sequence operation or light-load high-speed operation is currently in progress.



Remedy:

  • To cancel learning, suspend it and set learning parameters F329 to 0.


tun1
Brake sequence learning error

Cause: Braking operation is not performed normally.

The load is too heavy.

There are some operation errors.



Remedy:

  • Brake signal output (68, 69) is not assigned to the control output terminal.

  • The brake function mode selection parameter (F341) is not set.

  • Learning is performed while the load is lifted.


tun2
Light-load high-speed learning operation error

Cause: There are some errors in the operation for learning for light-load high-speed operation.



Remedy:

  • Check whether the learning operation for light-load high-speed operation is performed correctly. (Refer to 6.16)


tun3
Light-load high-speed learning overload error

Cause: Learning operation for light-load high-speed operation is performed while the load is lifted.

Motor constants (uL, uLv, F405 to F413) are not entered correctly.



Remedy:

  • Check the load.

  • Check the motor constant setting.


UndO
Key operation permitted temporarily

Cause: This message appears if the ENTER key is pressed and held down for 5 seconds or more when key operation is prohibited by F737.



Remedy:

  • When this message is displayed, all the keys are operational. To prohibit key operation again, turn off the inverter and then turn it back on.


C
Overcurrent pre-alarm

Cause: Same as OC (Overcurrent).



Remedy:

  • Same as OC (Overcurrent).


P
Overvoltage pre-alarm / PBR operation level

Cause: Same as OP (Overvoltage).

P blink while PBR is operating is not an error.



Remedy:

  • Same as OP (Overvoltage).

  • P blink while PBR is operating is not an error.


L
Overload pre-alarm

Cause: Same as OL1 and OL2 (Overload).



Remedy:

  • Same as OL1 and OL2 (Overload).


H
Overheat pre-alarm

Cause: Same as OH (Overheat).



Remedy:

  • Same as OH (Overheat).


t
Communication error

Cause: Various transmission errors occur when computer is linked up with inverter system.

Various transmission errors occur in inverter to inverter communication (slave side). Time-out or trip in master side.



Remedy:

  • For measures to correct various kinds of data transmission errors, refer to the instruction manual for the communications device used specified in Section 6.42.

  • Check the master inverter.