Toshiba NC1 Drives

Toshiba NC1 Drives Fault Codes:

Fault Code and MeaningCause and Remedy
OC1 / OC1P
Overcurrent during acceleration
Cause:

  • The acceleration time (ACC) is too short.

  • The V/F setting is improper.

  • A restart signal is input to the rotating motor after a momentary stop.

  • A special motor (e.g. motor with small impedance) is used.




Remedy:

  • Increase the acceleration time (ACC).

  • Check the V/F parameter.

  • Use F301 (auto-restart) and F302 (ride-through control).

  • Increase or decrease the carrier frequency (F300).
OC2 / OC2P
Overcurrent during deceleration
Cause:

  • The deceleration time (dEC) is too short.




Remedy:

  • Increase the deceleration time (dEC).
OC3 / OC3P
Overcurrent during operation
Cause:

  • The load fluctuates abruptly.

  • The load is in an abnormal condition.




Remedy:

  • Reduce the load fluctuation.

  • Check the load (operated machine).
OCR
Arm overcurrent at start-up
Cause:

  • A main circuit element is defective.




Remedy:

  • Make a service call.
OCL
Overcurrent (load side at start-up)
Cause:

  • The insulation of the output main circuit or motor is defective.

  • The motor has too small impedance.




Remedy:

  • Check the cables and wires for defective insulation.
OP1
Overvoltage during acceleration
Cause:

  • The input voltage fluctuates abnormally.

  • The power supply has a capacity of 200kVA or more.

  • A power factor improvement capacitor is opened or closed.

  • A system using a thyristor is connected to the same power distribution line.

  • A restart signal is input to the rotating motor after a momentary stop.




Remedy:

  • Insert a suitable input reactor.

  • Use F301 (auto-restart) and F302 (ride-through control).
OP2
Overvoltage during deceleration
Cause:

  • The deceleration time (dEC) is too short (Regenerative energy is too large).

  • F305 (overvoltage limit operation) is off.

  • The input voltage fluctuates abnormally.




Remedy:

  • Increase the deceleration time (dEC).

  • Enable F305 (overvoltage limit operation).

  • Insert a suitable input reactor.
OP3
Overvoltage during constant-speed operation
Cause:

  • The input voltage fluctuates abnormally.

  • The motor is in a regenerative state because the load causes the motor to run at a frequency higher than the inverter output frequency.




Remedy:

  • Insert a suitable input reactor.
OL1
Inverter overload
Cause:

  • The acceleration time (ACC) is too short.

  • The DC braking amount is too large.

  • The V/F setting is improper.

  • A restart signal is input to the rotating motor after a momentary stop.

  • The load is 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 F301 (auto-restart) and F302 (ride-through control).

  • Use an inverter with a larger rating.
OL2
Motor overload
Cause:

  • The V/F setting is improper.

  • The motor is locked up.

  • Low-speed operation is performed continuously.

  • An excessive load is applied to the motor during operation.




Remedy:

  • Check the V/F parameter setting.

  • Check the load (operated machine).

  • Adjust OLM to the overload that the motor can withstand during operation in a low speed range.
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.

  • Enable F605 (Output phase failure detection).
EPH1
Input phase failure
Cause:

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

  • The inverter may trip because of EPH1 if switching between acceleration and deceleration is done in succession at intervals of less than 1 second.




Remedy:

  • Check the main circuit input line for phase failure.

  • Enable F608 (input phase failure detection). Set the F608 parameter to 0.
OH
Overheat
Cause:

  • The cooling fan does not rotate.

  • The ambient temperature is too high.

  • The vent is blocked up.

  • A heat generating device is installed close to the inverter.

  • The thermistor in the unit is broken.




Remedy:

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

  • The fan requires replacement if it does not rotate during operation.

  • Secure sufficient space around the inverter.

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

  • Make a service call.
*UP1
Undervoltage trip (main circuit)
Cause:

  • The input voltage (in the main circuit) is too low.




Remedy:

  • Check the input voltage.

  • Enable F627 (undervoltage trip selection).

  • To cope with a momentary stop due to undervoltage, enable F302 (ride-through control) and F301 (auto-restart).
EF2
Ground fault trip / Arm overcurrent
Cause:

  • A ground fault occurs in the output cable or the motor.

  • A main circuit element is defective.




Remedy:

  • Check the cable and the motor for ground faults.

  • Make a service call.
E
Emergency stop
Cause:

  • During automatic operation or remote operation, a stop command is entered from the operation panel or a remote input device.




Remedy:

  • Reset the inverter.
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 trip
Cause:

  • The control CPU is defective.




Remedy:

  • Make a service call.
Err5
Remote control error
Cause:

  • An error arises during remote operation.




Remedy:

  • Check the remote control device, cables, etc.
Err7
Current detector fault
Cause:

  • The current detector is defective.




Remedy:

  • Make a service call.
EEP1
EEPROM fault 1
Cause:

  • A data writing error occurs.




Remedy:

  • Turn off the inverter, then turn it on again. If it does not recover from the error, make a service call.
EEP2
EEPROM fault 2
Cause:

  • Power supply is cut off during tyP operation and data writing is aborted.




Remedy:

  • Turn the power off temporarily and turn it back on, and then try tyP operation again.
EEP3
EEPROM fault 3
Cause:

  • A data writing error occurs.




Remedy:

  • Turn off the inverter, then turn it on again. If it does not recover from the error, make a service call.
E-18
Break in analog signal cable
Cause:

  • The signal input via VI/S3 is below the analog signal detection level set with F633.




Remedy:

  • Check the cables for breaks and change the setting of F633 if no breaks are found.
E-19
CPU communications error
Cause:

  • A communications error occurs between control CPUs.




Remedy:

  • Make a service call.
E-20
Excessive torque boosted
Cause:

  • The torque boost parameter (vb) is set too high.

  • The impedance of the motor is too small.




Remedy:

  • Decrease the setting of the torque boost parameter (vb).

  • If no improvement results, contact Toshiba Technical Support Center.
OFF
ST terminal OFF
Cause:

  • The ST-CC circuit is opened.




Remedy:

  • Close the ST-CC circuit.
nOFF
Undervoltage in main circuit
Cause:

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




Remedy:

  • Measure the main circuit supply voltage. If the voltage is at a normal level, the inverter requires repairing.
rtry
Retry in process
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. Be careful of the machine because it may suddenly restart.
Err1
Frequency point setting error
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 command acceptable
Cause:

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




Remedy:

  • Press the STOP key again to clear the trip.
EOFF
Emergency stop command acceptable
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.




Remedy:

  • Check whether the setting is made correctly.
HEAd / End
Display of first/last data items
Cause:

  • The first or last data item in the data group is displayed.




Remedy:

  • Press the MON key to exit the data group.
db
DC braking
Cause:

  • DC braking in process.




Remedy:

  • The message goes off in several tens of seconds if no problem occurs.
E1
Flowing out of excess number of digits
Cause:

  • The numeric value displayed (e.g., frequency) has a larger number of digits than the display panel.




Remedy:

  • When a frequency is displayed, decrease the setting of F702 (free unit).
StOP
Momentary power failure slowdown stop prohibition
Cause:

  • The slowdown stop prohibition function set with F302 (momentary power failure ride-through operation) is activated.




Remedy:

  • To restart operation, reset the inverter or input an operation signal again.
Init
Parameters in the process of initialization
Cause:

  • Parameters are being initialized to default values.




Remedy:

  • Normal if the message disappears after a while.
E-17
Operation panel key fault
Cause:

  • The RUN or STOP key is held down for more than 5 seconds.

  • The RUN or STOP key is faulty.




Remedy:

  • Check the operation panel.
E-50
Source logic switching confirmation alarm
Cause:

  • The input terminal is switched to source logic mode.




Remedy:

  • Check whether cables are connected correctly, and then specify a proper logic.

  • Check whether cables are connected correctly, and then reset the inverter or turn it off temporarily and turn it back on. Logics will be switched.
C, P, L, H
Alarms displayed during operation
Cause:

  • C: Overcurrent alarm

  • P: Overvoltage alarm

  • L: Overload alarm

  • H: Overheat alarm




Remedy:

  • If two or more problems arise simultaneously, they blink in order C, P, L, H.