Hitachi S1 Drive

Hitachi S1 Drive Fault Codes:

Fault Code and MeaningCause and Remedy
OUt1
Inverter unit Phase-U protection
Cause: Acceleration is too fast; IGBT module is damaged; Misacts caused by interference; drive wires are poorly connected.



Remedy:

  • Increase acceleration time.

  • Replace the power unit.

  • Check drive wires.

  • Check whether there is strong interference surrounding the peripheral equipment.
OUt2
Inverter unit Phase-V protection
Cause: Acceleration is too fast; IGBT module is damaged; Misacts caused by interference; drive wires are poorly connected.



Remedy:

  • Increase acceleration time.

  • Replace the power unit.

  • Check drive wires.

  • Check whether there is strong interference surrounding the peripheral equipment.
OUt3
Inverter unit Phase-W protection
Cause: To-ground short circuit occurs; IGBT module damage; Interference.



Remedy:

  • Check peripheral equipment.

  • Check drive wires.

  • Replace power unit if necessary.
OV1
Over-voltage during acceleration
Cause: Exception occurred to input voltage; Large energy feedback; Lack of brake units; Dynamic brake is not enabled.



Remedy:

  • Check input power.

  • Check whether load deceleration time is too short.

  • Check if the motor starts during rotating.

  • Install dynamic brake units.

  • Check the setup of related function codes.
OV2
Over-voltage during deceleration
Cause: Exception occurred to input voltage; Large energy feedback; Lack of brake units.



Remedy:

  • Check input power.

  • Check whether load deceleration time is too short.

  • Install dynamic brake units.

  • Check the setup of related function codes.
OV3
Over-voltage during constant speed running
Cause: Exception occurred to input voltage; Large energy feedback; Dynamic brake is not enabled.



Remedy:

  • Check input power.

  • Install dynamic brake units.

  • Check the setup of related function codes.
OC1
Over-current during acceleration
Cause: Acceleration is too fast; Grid voltage is too low; Inverter power is too small; Load transient or exception occurred.



Remedy:

  • Increase acceleration time.

  • Check input power.

  • Select the inverter with larger power.

  • Check if the load is short circuited (to-ground or line-to-line).

  • Check if the rotation is smooth.
OC2
Over-current during deceleration
Cause: Deceleration is too fast; Load transient; Inverter power is too small.



Remedy:

  • Increase deceleration time.

  • Check input power.

  • Select the inverter with larger power.

  • Check the output wiring.
OC3
Over-current during constant speed running
Cause: Load transient; To-ground short circuit or output phase loss occur; Strong external interference sources; Overvoltage stall protection is not enabled.



Remedy:

  • Check if the load is short circuited.

  • Check the output wiring.

  • Check if there is strong interference.

  • Check the setup of related function codes.
UV
Bus undervoltage fault
Cause: Grid voltage is too low; Overvoltage stall protection is not enabled.



Remedy:

  • Check grid input power.

  • Check the setup of related function codes.
OL1
Motor overload
Cause: Grid voltage is too low; Rated motor current is set improperly; Motor stall or load jumps violently.



Remedy:

  • Check grid voltage.

  • Reset rated motor current.

  • Check the load and adjust torque boost.
OL2
Inverter overload
Cause: Acceleration is too fast; The motor in rotating is restarted; Grid voltage is too low; Load is too large; Power is too small.



Remedy:

  • Increase acceleration time.

  • Avoid restart after stop.

  • Check grid voltage.

  • Select the inverter with larger power.

  • Select proper motor.
SPI
Phase loss on input side
Cause: Phase loss or violent fluctuation occurred to R, S and T input.



Remedy:

  • Check the input power.

  • Check installation wiring.
SPO
Phase loss on output side
Cause: Phase loss occurred to U, V, W output (or the three phases of motor is asymmetrical).



Remedy:

  • Check the output wiring.

  • Check the motor and cable.
OH1
Overheat of rectifier module
Cause: Air duct is blocked or fan is damaged; Ambient temperature is too high; Long-time overload running.



Remedy:

  • Ventilate the air duct or replace the fan.

  • Lower the ambient temperature.
OH2
Overheat of inverter module
Cause: Air duct blocked; Fan damaged; High ambient temperature; Long-time overload.



Remedy:

  • Ventilate the air duct or replace the fan.

  • Lower the ambient temperature.
EF
External fault
Cause: External fault input terminal acts.



Remedy:

  • Check external device input.
CE
485 communication fault
Cause: Baud rate is set improperly; Communication line fault; Communication address error; Communication suffers from strong interference.



Remedy:

  • Set proper baud rate.

  • Check the wiring of communication interfaces.

  • Set proper communication address.

  • Replace or change the wiring to enhance anti-interference capacity.
ItE
Current detection fault
Cause: Poor contact of the connector of control board; Hall component is damaged; Exception occurred to amplification circuit.



Remedy:

  • Check the connector and re-plug.

  • Replace the hall component.

  • Replace the main control board.
tE
Motor autotuning fault
Cause: Motor capacity does not match inverter; Motor parameter set improperly; Autotuning parameters deviate sharply; Autotuning timeout.



Remedy:

  • Change the inverter model, or adopt V/F mode for control.

  • Set proper motor type and nameplate parameters.

  • Empty the motor load and carry out autotuning again.

  • Check motor wiring and parameter setup.

  • Check whether upper limit frequency is larger than 2/3 of the rated frequency.
EEP
EEPROM fault
Cause: R/W error occurred to the control parameters; EEPROM is damaged.



Remedy:

  • Press STOP/RST to reset.

  • Replace the main control board.
PIDE
PID feedback offline fault
Cause: PID feedback offline; PID feedback source disappears.



Remedy:

  • Check PID feedback signal wires.

  • Check PID feedback source.
bCE
Brake unit fault
Cause: Brake circuit fault or brake tube is damaged; The resistance of external brake resistor is too small.



Remedy:

  • Check the brake unit, replace with new brake tubes.

  • Increase brake resistance.
END
Running time is up
Cause: The actual running time of the inverter is larger than the set running time.



Remedy:

  • Ask help from the supplier.

  • Adjust the set running time.
OL3
Electronic overload fault
Cause: The inverter releases overload pre-alarm based on the set value.



Remedy:

  • Check the load and overload pre-alarm threshold.
PCE
Keypad communication fault
Cause: Keypad wire poorly contacted or disconnected; Keypad wire too long/strong interference; Circuit fault to keypad/main board.



Remedy:

  • Check the keypad wires to confirm whether fault exists.

  • Check the surroundings to rule out interference source.

  • Replace the hardware and ask for maintenance service.
UPE
Parameter upload error
Cause: Keypad wire poorly contacted or disconnected; Keypad wire too long/strong interference; Circuit fault.



Remedy:

  • Check the surroundings to rule out interference source.

  • Replace the hardware and ask for maintenance service.
DNE
Parameter download error
Cause: Keypad wire poorly contacted/disconnected; Keypad wire too long/interference; Data storage error.



Remedy:

  • Check the surroundings to rule out interference source.

  • Replace the hardware and ask for maintenance service.

  • Re-backup keypad data.
ETH1
To-ground short circuit fault 1
Cause: Inverter output is short connected to the ground; Current detection circuit is faulty; Actual motor power setup deviates sharply.



Remedy:

  • Check whether motor wiring is proper.

  • Replace the hall component.

  • Replace the main control board.

  • Reset the motor parameters properly.
ETH2
To-ground short circuit fault 2
Cause: Inverter output is short connected to ground; Current detection circuit is faulty; Actual motor power setup deviates sharply.



Remedy:

  • Check whether motor wiring is proper.

  • Replace the hall component.

  • Replace the main control board.

  • Reset the motor parameters properly.
LL
Electronic underload fault
Cause: The inverter performs underload pre-alarm based on the set value.



Remedy:

  • Check the load and overload pre-alarm threshold.
STO
Safe torque off
Cause: Safe torque off function is enabled by external forces.



Remedy:

  • (No corrective measure listed for normal operation/external trigger).
STL1
Exception occurred to safe circuit of channel H1
Cause: The wiring of STO is improper; Fault occurred to external switch of STO; Hardware fault occurred to safety circuit of channel H1.



Remedy:

  • Check whether terminal wiring of STO is proper and firm enough.

  • Check whether external switch of STO can work properly.

  • Replace the control board.
STL2
Exception occurred to channel H2 safe circuit
Cause: The wiring of STO is improper; Fault occurred to external switch of STO; Hardware fault occurred to safety circuit of channel H2.



Remedy:

  • Check whether terminal wiring of STO is proper and firm enough.

  • Check whether external switch of STO can work properly.

  • Replace the control board.
STL3
Exception occurred to channel H1 and channel H2
Cause: Hardware fault occurred to STO circuit.



Remedy:

  • Replace the control board.
CrCE
Safety code FLASH CRC check fault
Cause: Control board is faulty.



Remedy:

  • Replace the control board.
PoFF
System power failure
Cause: The system is powered off or the bus voltage is too low.



Remedy:

  • Check the grid conditions.