Yaskawa L1000A Drive

Yaskawa L1000A Drive Fault Codes:

Fault Code and MeaningCause and Remedy
boL
Braking Transistor Overload
Cause: The wrong braking resistor is installed (transistor reached overload level).



Remedy:

  • Make sure the rating of the braking resistor fits drive and application.

  • Use an external braking transistor if necessary.
bUS
Option Communication Error
Cause: Connection lost after initial communication, No signal from PLC, Faulty wiring, Noise, or Damaged option card.



Remedy:

  • Check for faulty wiring, disconnected cables, or short circuits.

  • Counteract noise in control/main circuit and ground wiring.

  • Use surge absorbers on switches/relays.

  • Use shielded lines and ground the shield properly.

  • Separate communication wiring from power lines.

  • Replace the option card if wiring is correct but error persists.

  • Reinstall the option card ensuring pins line up properly.
CE
MEMOBUS/Modbus Communication Error
Cause: Communication data not received (Time set in H5-09), Faulty wiring, or Noise interference.



Remedy:

  • Check for faulty wiring, disconnected cables, or short circuits.

  • Counteract noise in control/main circuit and ground wiring.

  • Ensure other equipment (switches/relays) do not cause noise; use surge absorbers.

  • Use shielded lines and ground properly.

  • Install an EMC noise filter to the drive power supply input.
CF
Control Fault
Cause: Torque limit reached continuously for 3 seconds (OLV Control), Improper motor parameters, or Load inertia too big.



Remedy:

  • Check motor parameter settings and repeat Auto-Tuning.

  • Set torque limit to appropriate setting (L7-01 through L7-04).

  • Adjust the deceleration ramp (C1-02, -04, -06, -08).

  • Set speed reference to minimum and interrupt Up/Down command when drive finishes decelerating.
CoF
Current Offset Fault
Cause: Current sensor damaged or residual induction current in motor (e.g., during sudden deceleration).



Remedy:

  • Create a motor restart sequence allowing residual induction voltage to dissipate.

  • Enable Speed Search at start (b3-01 = 1).

  • Use multi-function terminals to execute External Speed Search 1 and 2.

  • If hardware is damaged, replace the drive.
CPF00 or CPF01
Control Circuit Error
Cause: Self-diagnostic error in control circuit or Connector on operator is damaged.



Remedy:

  • Cycle power to the drive.

  • Set frequency to minimum and interrupt Run command when drive finishes decelerating.

  • Replace the operator if the connector is damaged.
CPF02
A/D Conversion Error
Cause: Control circuit is damaged (A/D conversion error).



Remedy:

  • Cycle power to the drive.

  • If problem continues, replace the control board or entire drive.
CPF03
Control Board Connection Error
Cause: Connection error between control board and drive, or Noise interference.



Remedy:

  • Turn off power and check connection between control board and drive.

  • Check for noise options; counteract noise in circuits.

  • Use shielded lines and ground properly.

  • Install EMC noise filter.

  • If problem continues, replace control board.
CPF06
EEPROM Memory Data Error
Cause: Error in EEPROM control circuit, or power lost while saving parameters.



Remedy:

  • Cycle power and check connection between control board and drive.

  • Reinitialize the drive (A1-03).

  • If problem continues, replace control board or drive.
CPF07 or CPF08
Terminal Board Connection Error
Cause: Faulty connection between terminal board and control board.



Remedy:

  • Turn off power and check connection between control board and drive.

  • If problem continues, replace control board or entire drive.
CPF11 to CPF14
CPF16 to CPF21
Control Circuit Error
Cause: Hardware is damaged (RAM/ROM/CPU errors).



Remedy:

  • Cycle power to the drive.

  • If problem continues, replace the control board or entire drive.
CPF22
Hybrid IC Failure
Cause: Hybrid IC failure on the power board.



Remedy:

  • Cycle power to the drive.

  • If problem continues, replace the control board or entire drive.
CPF23
Control Board Connection Error
Cause: Hardware is damaged (Connection error).



Remedy:

  • Turn power off and check connection between control board and drive.

  • If problem continues, replace control board.
CPF24
Drive Unit Signal Fault
Cause: Hardware damaged (Drive capacity cannot be detected correctly).



Remedy:

  • If problem continues, replace the control board or entire drive.
CPF25
Terminal Board not Connected
Cause: Terminal board is not connected correctly.



Remedy:

  • Reconnect the terminal board to the connector on the drive.

  • Cycle power to the drive.
CPF26 to CPF34
Control Circuit Error (CPU Error)
Cause: Hardware is damaged.



Remedy:

  • If problem continues, replace the control board or entire drive.
CPF35
A/D Conversion Error
Cause: A/D conversion damaged or Control circuit damaged.



Remedy:

  • Cycle power to the drive.

  • If problem continues, replace control board or entire drive.
dEv
Speed Deviation
Cause: Load too heavy, Accel/decel too short, Load locked, Parameters F1-10/F1-11 set incorrectly, or Brake not applied.



Remedy:

  • Reduce the load.

  • Increase acceleration/deceleration times (C1-01 to C1-08).

  • Check the machine/load.

  • Check settings of F1-10 and F1-11.

  • Ensure motor brake operates properly.

  • Check DC bus voltage setting for Rescue Operation (S4-12).
dv1
Encoder Z Pulse Fault
Cause: Encoder not connected, wired improperly, or damaged.



Remedy:

  • Make sure encoder is properly connected and shielded lines grounded.

  • Replace PG option card or encoder if problem persists.
dv2
Z Pulse Noise Fault Detection
Cause: Noise interference on encoder cable, Wiring improper, or Hardware damaged.



Remedy:

  • Separate encoder cable lines from noise source.

  • Rewire encoder and ensure proper grounding.

  • Replace PG option card or encoder.
dv3
Inversion Detection
Cause: Encoder offset (E5-11) not set, External force moved load, Noise interference, or Phase order incorrect.



Remedy:

  • Set encoder offset to E5-11 as specified on motor nameplate.

  • Make sure motor is rotating in the right direction.

  • Rewire PG encoder using shielded line.

  • Properly connect motor lines (U/T1, V/T2, W/T3).
dv4
Inversion Prevention Detection
Cause: Encoder offset not set properly (E5-11), Noise interference, or Disconnected encoder.



Remedy:

  • Set encoder offset to E5-11 as specified on motor nameplate.

  • Check if motor is rotating in correct direction.

  • Rewire encoder with shielded line.

  • Replace PG option card or encoder if damaged.
dv6
Overacceleration Detection
Cause: Encoder offset (E5-11) incorrect, Noise, Incorrect motor data, or Acceleration too fast.



Remedy:

  • Set E5-11 to offset value on motor nameplate.

  • Check encoder wiring for loose connections; ground shields.

  • Check E5 parameters match motor nameplate.

  • Check and adjust acceleration rate and jerk (C2-01).
dv7
Rotor Polarity Detection Timeover
Cause: Battery low, Cable disconnected, Motor winding damaged, or Terminal loose.



Remedy:

  • Charge the battery.

  • Check wiring errors and output cable connection.

  • Check resistance between motor lines; replace motor if needed.

  • Apply tightening torque to terminals.
dv8
PM Rotor Position Estimation Error
Cause: Motor characteristics changed, Initial Pole Search parameters incorrect, Brake released during search.



Remedy:

  • Repeat setup process (Stationary Auto-Tuning).

  • Check brake sequence; brake must remain applied during search.

  • Use a PG option card compatible with absolute encoder if needed.
EF0
Option Card External Fault
Cause: External fault received from PLC, or PLC program problem.



Remedy:

  • Remove the cause of the external fault.

  • Remove external fault input from PLC.

  • Check PLC program and correct problems.
EF3 to EF8
External Fault (Input Terminals S3 to S8)
Cause: External device tripped alarm, Wiring incorrect, or Incorrect multi-function input setting.



Remedy:

  • Remove cause of external fault and reset.

  • Ensure signal lines connected to correct terminals (H1-xx = 20 to 2B).

  • Check for unused terminals set to External Fault.
Err
EEPROM Write Error
Cause: Noise corrupted data while writing to EEPROM, or Hardware problem.



Remedy:

  • Press [ENTER].

  • Correct parameter setting and cycle power.

  • If problem continues, replace control board or drive.
FrL
Speed Reference Missing
Cause: Parameter d1-18 set incorrectly, or no speed selected at start.



Remedy:

  • Check d1-18 and H1-xx settings match elevator controller.

  • Ensure elevator controller is connected and selects speed properly.
GF
Ground Fault
Cause: Motor insulation damaged, Motor cable short circuit, Leakage current too high, or Hardware problem.



Remedy:

  • Check insulation resistance of motor; replace if needed.

  • Check motor cable and remove short circuit.

  • Reduce carrier frequency to lower leakage current.

  • If hardware problem, replace control board or drive.
LF
Output Phase Loss
Cause: Output cable disconnected, Motor winding damaged, Terminal loose, or Single-phase motor used.



Remedy:

  • Check for wiring errors and connect output cable properly.

  • Check resistance between motor lines.

  • Tighten loose terminals.

  • Check drive and motor capacities.

  • Drive cannot operate a single-phase motor.
LF2
Output Current Imbalance
Cause: Phase loss on output side, Loose terminals, Output circuit damaged, or Motor impedance uneven.



Remedy:

  • Check for faulty wiring or poor connections on output side.

  • Tighten terminals.

  • Measure line-to-line resistance for each motor phase.

  • If output circuit damaged, replace control board or drive.
oC

Overcurrent
Cause: The motor has been damaged due to overheating or the motor insulation is damaged.


Remedy:

  • Check the insulation resistance.

  • Replace the motor.




Cause: One of the motor cables has shorted out or there is a grounding problem.


Remedy:

  • Check the motor cables.

  • Remove the short circuit and reapply power to the drive.

  • Check the resistance between the motor cables and the ground terminal.

  • Replace damaged cables.




Cause: The drive is damaged.


Remedy:

  • Check the drive output side short circuit for broken output transistor (B1, U/V/W).

  • Contact your Yaskawa representative.




Cause: The load is too heavy.


Remedy:

  • Measure the current flowing into the motor.

  • Replace the drive with a larger capacity drive if current exceeds rated current.

  • Reduce the load to avoid sudden changes.




Cause: Accel/decel ramp is too fast.


Remedy:

  • Reduce the acceleration and/or deceleration ramp (increase time).

  • Use a larger capacity drive.
oFA00

Option Card Connection Error (CN5-A)
Cause: The option card installed into port CN5-A is incompatible with the drive.


Remedy:

  • Check if the drive supports the option card to be installed. Contact Yaskawa for assistance.




Cause: A PG option card is connected to option port CN5-A.


Remedy:

  • PG option cards are supported by option ports CN5-B and CN5-C only. Place the PG option card into the correct option port.
oFA01

Option Card Fault (CN5-A)
Cause: The option board connection to port CN5-A is faulty.


Remedy:

  • Turn the power off and reconnect the option card.

  • Check if the option card is properly plugged into the option port.

  • If the error persists, replace the option card or the drive.
oFA05, oFA06, oFA10-oFA17, oFA30-oFA43

Option card error at CN5-A
Cause: Option card or hardware is damaged.


Remedy:

  • Cycle power to the drive.

  • If the problem continues, replace the control board or the entire drive.
oFb00

Option Card Fault (CN5-B)
Cause: The option card installed into port CN5-B is incompatible with the drive.


Remedy:

  • Make sure the drive supports the option card to be installed.




Cause: A communication option card has been installed in option port CN5-B.


Remedy:

  • Communication option cards are only supported by option port CN5-A.
oFb01

Option Card Fault (CN5-B) Not Connected
Cause: The option board connection to port CN5-B is faulty.


Remedy:

  • Turn off the power and reconnect the option card.

  • Check if the card is fixed properly.

  • Try to use the card in another option port (if applicable).
oFb02

Option Card Fault (CN5-B) Duplicate
Cause: An option card of the same type is already installed in option port CN5-A.


Remedy:

  • Make sure only one type of option card is connected (except PG options).
oFb03 to oFb17

Option card error at CN5-B
Cause: Option card or hardware is damaged.


Remedy:

  • Cycle power to the drive.

  • If problem continues, replace control board or drive.
oFC00

Option Card Connection Error (CN5-C)
Cause: The option card installed into port CN5-C is incompatible with the drive.


Remedy:

  • Confirm that the drive supports the option card.




Cause: A communication option card has been installed in option port CN5-C.


Remedy:

  • Communication option cards are only supported by option port CN5-A.
oFC01

Option Card Fault (CN5-C)
Cause: The option board connection to port CN5-C is faulty.


Remedy:

  • Turn the power off and reconnect the option card.

  • Check if the option card is properly plugged in.
oFC02

Option Card Fault (CN5-C) Duplicate
Cause: Three PG option boards are installed.


Remedy:

  • A maximum of two PG option boards can be used simultaneously. Remove the PG option board installed into option port CN5-A.
oFC50

Encoder Option AD Conversion Error
Cause: The PG option card is damaged.


Remedy:

  • Replace the PG option card.
oFC51

Encoder Option Analog Circuit Error
Cause: The PG option card is damaged.


Remedy:

  • Replace the PG option card.
oFC52

Encoder Communication Timeout
Cause: Encoder cable wiring is wrong or disconnected.


Remedy:

  • Correct the wiring or reconnect the cable.




Cause: Parameters for Encoder Selection (F1-50) are set to the wrong values.


Remedy:

  • Set parameter F1-50 to the proper value.
oFC53

Encoder Communication Data Error
Cause: Encoder cable wiring is wrong or disconnected.


Remedy:

  • Correct the wiring or reconnect the cable.
oFC54

Encoder Error
Cause: Power supply to encoder is wired incorrectly.


Remedy:

  • Correct the wiring.




Cause: The power supply circuit of the PG option card is damaged.


Remedy:

  • Replace the PG option card.
oH

Heatsink Overheat (Pre-alarm)
Cause: Surrounding temperature is too high.


Remedy:

  • Check the temperature surrounding the drive.

  • Improve air circulation or install a fan/AC.

  • Remove heat sources near the drive.




Cause: Load is too heavy.


Remedy:

  • Measure output current.

  • Decrease load or lower carrier frequency (C6-03).




Cause: Internal cooling fan is stopped.


Remedy:

  • Replace the cooling fan.

  • Reset cooling fan maintenance parameter (o4-03 = 0).
oH1

Heatsink Overheat (Fault)
Cause: Surrounding temperature is too high.


Remedy:

  • Check temperature, improve circulation, install fan/AC.




Cause: Load is too heavy.


Remedy:

  • Decrease load or lower carrier frequency.
oH3

Motor Overheat Alarm (PTC)
Cause: Motor thermostat wiring is faulty.


Remedy:

  • Repair the PTC thermistor input wiring.




Cause: Motor has overheated.


Remedy:

  • Check load size, cycle times, and V/f pattern.

  • Reduce load or increase accel/decel times.

  • Ensure motor cooling system is operating.
oH4

Motor Overheat Fault (PTC)
Cause: Motor thermostat wiring is faulty.


Remedy:

  • Repair the PTC thermistor input wiring.




Cause: Motor has overheated.


Remedy:

  • Check load size, cycle times, and V/f pattern.

  • Reduce load or increase accel/decel times.

  • Ensure motor cooling system is operating.
oL1

Motor Overload
Cause: Load is too heavy.


Remedy:

  • Reduce the load.




Cause: Cycle times are too short during acceleration/deceleration.


Remedy:

  • Increase the acceleration and deceleration times (C1-01 through C1-08).




Cause: Output voltage is too high.


Remedy:

  • Adjust V/f pattern (reduce E1-08 and E1-10).




Cause: The wrong motor rated current is set to E2-01.


Remedy:

  • Enter the value written on the motor nameplate to parameter E2-01.
oL2

Drive Overload
Cause: Load is too heavy.


Remedy:

  • Reduce the load.




Cause: Accel/decel ramp is too short.


Remedy:

  • Increase the settings for acceleration and deceleration times.




Cause: Drive capacity is too small.


Remedy:

  • Replace the drive with a larger model.
oL3

Overtorque Detection 1
Cause: Parameter settings are not appropriate for the load.


Remedy:

  • Check the settings of parameters L6-02 and L6-03.




Cause: Fault on the machine side (e.g., machine is locked up).


Remedy:

  • Check the status of the load. Remove the cause of the fault.
oL4

Overtorque Detection 2
Cause: Parameter settings are not appropriate for the load.


Remedy:

  • Check the settings of parameters L6-05 and L6-06.
oPr

External Operator Connection Fault
Cause: External operator is not properly connected to the drive.


Remedy:

  • Check the connection between the operator and the drive.

  • Replace the cable if damaged.

  • Reconnect the operator and turn power back on.
oS

Overspeed
Cause: Overshoot is occurring.


Remedy:

  • Reduce settings for C5-01 and increase C5-02.

  • Enable Inertia Compensation if using closed loop vector mode.




Cause: Inappropriate parameter settings.


Remedy:

  • Check setting for overspeed detection level/time (F1-08 and F1-09).
ov

DC Bus Overvoltage
Cause: Deceleration ramp is too short and regenerative energy is flowing back.


Remedy:

  • Increase the deceleration ramp (C1-02, C1-04, etc).

  • Make sure braking resistor/transistor is connected properly.




Cause: Surge voltage entering from drive input power.


Remedy:

  • Install a DC link choke.




Cause: Ground fault in the output circuit.


Remedy:

  • Check motor wiring for ground faults.




Cause: Drive input power voltage is too high.


Remedy:

  • Lower drive input power voltage within specifications.
PF

Input Phase Loss
Cause: There is phase loss in the drive input power.


Remedy:

  • Check for wiring errors in the main circuit drive input power.

  • Correct the wiring.




Cause: There is loose wiring in the drive input power terminals.


Remedy:

  • Ensure the terminals are tightened properly.




Cause: The main circuit capacitors are worn.


Remedy:

  • Check maintenance time for capacitors (U4-05). Replace if necessary.
PF5

Rescue Operation Power Supply Error
Cause: During Rescue Operation, DC bus voltage dropped too low.


Remedy:

  • Check the DC bus voltage setting for Rescue Operation (S4-12).

  • Lower the speed reference set for Rescue Operation (S4-15).

  • Check the backup power supply (UPS).
PGo
Encoder Disconnected (Control Mode with Encoder)
Cause: Encoder cable disconnected, wrong wiring, no power, or motor brake not released.



Remedy:

  • Reconnect the cable.

  • Correct the wiring.

  • Check the power line to the encoder.

  • Ensure the motor brake releases properly.

  • For Rescue Operation issues: Check DC bus voltage setting (S4-12), lower speed reference (S4-15), or check backup power supply (UPS).
PGoH
Encoder Disconnected (detected when using an encoder)
Cause: Encoder cable is not connected properly.



Remedy:

  • Reconnect the cable.
rF
Braking Resistor Fault
Cause: Resistance of braking resistor is too low, proper option not installed, or wiring issue with regenerative unit.



Remedy:

  • Select the braking resistor option that fits the drive’s transistor specification.

  • If using a regenerative unit and terminals are connected incorrectly, disable braking transistor protection (set L8-55 to 1).
rr
Dynamic Braking Transistor Fault
Cause: The built-in dynamic braking transistor or control circuit is damaged.



Remedy:

  • Cycle power to the drive and check if fault reoccurs.

  • Replace the control board or the entire drive.
SC
IGBT Short Circuit
Cause: IGBT fault, short circuit/ground fault, or drive damage.



Remedy:

  • Check wiring to the motor.

  • Turn power off and on to check operation.

  • Check drive output side for short circuit (B1, U/V/W).

  • If problem continues, contact Yaskawa representative.
SCF
Safety Circuit Fault
Cause: The safety circuit is damaged.



Remedy:

  • If the problem continues, replace the control board or the entire drive.
SE1
Motor Contactor Response Error
Cause: Problem with motor contactor or auxiliary switch.



Remedy:

  • Check the motor contactor, auxiliary switches, and wiring of the contactor feedback signal.
SE2
Starting Current Error
Cause: The motor contactor is open (current lower than 25% of no-load current at start).



Remedy:

  • Check the contactor for any problems.
SE3
Output Current Error
Cause: The motor contactor opened during operation.



Remedy:

  • Check the contactor for any problems.
SE4
Brake Feedback Error
Cause: Feedback contact defective, wiring incorrect, brake control circuit fail, or contactor open.



Remedy:

  • Check the brake feedback contact and wiring.

  • Ensure motor brake operates properly with brake control command.

  • Check the contactor. If Brake Response Monitor is enabled (S6-07=1), reset fault to set S6-08 to 1 if no problems found.
SvE
Position Lock Error
Cause: Torque limit too low, excessive load torque, or noise interference.



Remedy:

  • Set torque limit to appropriate value (L7-01 to L7-04).

  • Reduce the amount of load torque.

  • Check the encoder signal for noise interference.
STo
Motor Pull Out or Step Out Detection
Cause: Wrong motor code, load too heavy, or accel/decel ramp too short.



Remedy:

  • Enter correct motor code (E5 parameters).

  • Reduce the load or increase drive capacity.

  • Increase acceleration/deceleration times (C1-01 to C1-08).

  • Increase jerk setting (C2-02 to C2-05).
UL3
Undertorque Detection 1
Cause: Parameter settings inappropriate or fault on machine side.



Remedy:

  • Check settings of parameters L6-02 and L6-03.

  • Check the load for any problems.
UL4
Undertorque Detection 2
Cause: Parameter settings inappropriate or fault on machine side.



Remedy:

  • Check settings of parameters L6-05 and L6-06.

  • Check the load for any problems.
Uv1
DC Bus Undervoltage
Cause: Input phase loss, loose terminals, voltage problem, power interrupt, worn capacitors, or soft-charge relay damage.



Remedy:

  • Check main circuit drive input power wiring.

  • Tighten terminals to specified torque.

  • Check voltage is within range.

  • Check main circuit magnetic contactor.

  • Check capacitor maintenance time (U4-05). Replace drive/board if >90%.

  • Cycle power. If fault reoccurs, replace control board or drive.
Uv2
Control Power Supply Voltage Fault
Cause: Control power supply wiring damaged or internal circuitry damaged.



Remedy:

  • Cycle power to the drive. Check if fault reoccurs.

  • Replace the control board, entire drive, or control power supply.
Uv3
Soft-Charge Bypass Circuit Fault
Cause: The relay or contactor on the soft-charge bypass circuit is damaged.



Remedy:

  • Cycle power and see if fault reoccurs.

  • Check monitor U4-06 for performance life.

  • Replace control board or entire drive if U4-06 exceeds 90% or problem continues.
voF
Output Voltage Detection Error
Cause: Hardware is damaged.



Remedy:

  • Replace either the control board or the entire drive.
AEr
Communication Option Node ID Setting Error (CANopen)
Cause: Option card node address is outside the acceptable setting range.


Remedy:

  • Set parameter F6-35 to the proper value if a CANopen option card is used.
bb
Baseblock
Cause: Drive output interrupted as indicated by an external baseblock signal (entered via multi-function input terminals S3 to S8).


Remedy:

  • Check external sequence and baseblock signal input timing.
boL
Braking Transistor Overload
Cause: The braking transistor in the drive has been overloaded (proper braking resistor not installed).


Remedy:

  • Select the optimal braking resistor.
bUS
Option Communication Error
Cause: Connection broken, master controller stopped, option card damaged, or data error due to noise.


Remedy:

  • Check for faulty wiring or disconnected cables.

  • Correct the wiring and repair short circuits as needed.

  • If wiring is correct but fault persists, replace the option card.

  • Ensure connector pins on the option card are lined up properly with the drive.

  • Take steps to counteract noise in control circuit wiring and main circuit lines.

  • Use surge absorbers on magnetic contactors.

  • Use shielded lines and ground the shield properly.

  • Install an EMC noise filter to the drive input power.
CALL
Serial Communication Stand By
Cause: Communication has not yet been established. Could be faulty wiring, programming error on master side, or damaged circuitry.


Remedy:

  • Check for wiring errors, disconnected cables, or short circuits.

  • Check communications at start-up and correct programming errors.

  • Perform a self-diagnostics check.

  • Replace control board or entire drive if circuitry is damaged.

  • Ensure termination resistor is installed at both ends of the communication line (DIP switch S2 to ON).
CE
MEMOBUS/Modbus Communication Error
Cause: Control data was not received correctly for two seconds (noise, incompatible protocol, or hardware problem).


Remedy:

  • Check options available to minimize noise effects.

  • Separate comm. device wiring from drive input power lines.

  • Check H5 parameter settings and protocol settings in the controller.

  • Set a longer Communication Fault Detection Time (H5-09).

  • Check the connector to make sure the cable has a signal.

  • Replace the communications cable.
CrST
Cannot Reset
Cause: A fault reset command was entered while the Up/Down command was still present.


Remedy:

  • Ensure that a Up/Down command cannot be entered from the external terminals or option card during fault reset.

  • Turn off the Up/Down command.
dEv
Speed Deviation (using PG option card)
Cause: Deviation between speed reference and feedback is greater than setting in F1-10 for longer than time in F1-11.


Remedy:

  • Reduce the load.

  • Increase acceleration and deceleration times (C1-01 through C1-08).

  • Check the machine for lock-ups.

  • Check settings of parameters F1-10 and F1-11.

  • Ensure the motor brake operates properly.
EF
Up/Down Command Error
Cause: Both forward run and reverse run closed simultaneously for over 0.5 s.


Remedy:

  • Check the forward and reverse command sequence and correct the problem.

  • Note: When minor fault EF is detected, motor ramps to stop.
EF0
Option Card External Fault
Cause: An external fault condition is present (received from PLC).


Remedy:

  • Remove the cause of the external fault.

  • Remove the external fault input from the PLC.

  • Check the PLC program and correct problems.
EF3
External fault (input terminal S3)
Cause: External fault at multi-function input terminal S3.


Remedy:

  • Remove the cause of the external fault and reset the multi-function input value.

  • Ensure signal lines are connected properly (H1-xx = 2C to 2F).

  • Reconnect the signal line.

  • Check if unused terminals have been set for External Fault incorrectly.
EF4
External fault (input terminal S4)
Cause: External fault at multi-function input terminal S4.


Remedy:

  • Remove the cause of the external fault and reset the multi-function input value.

  • Check wiring and terminal settings.
EF5
External fault (input terminal S5)
Cause: External fault at multi-function input terminal S5.


Remedy:

  • Remove the cause of the external fault and reset the multi-function input value.

  • Check wiring and terminal settings.
EF6
External fault (input terminal S6)
Cause: External fault at multi-function input terminal S6.


Remedy:

  • Remove the cause of the external fault and reset the multi-function input value.

  • Check wiring and terminal settings.
EF7
External fault (input terminal S7)
Cause: External fault at multi-function input terminal S7.


Remedy:

  • Remove the cause of the external fault and reset the multi-function input value.

  • Check wiring and terminal settings.
EF8
External fault (input terminal S8)
Cause: External fault at multi-function input terminal S8.


Remedy:

  • Remove the cause of the external fault and reset the multi-function input value.

  • Check wiring and terminal settings.
Hbb
Safe Disable Circuit Fault Signal
Cause: Both Safe Disable Input channels are open (H1 and H2).


Remedy:

  • Check signal status at the input terminals H1 and H2.

  • Check the Sink/Source Selection for the digital inputs.

  • If Safe Disable function is not utilized, check if H1-HC and H2-HC are linked.

  • If internally broken, replace control board or drive.
HbbF
Safe Disable Circuit Fault Signal (One Channel)
Cause: One Safe Disable channel is open while the other is closed.


Remedy:

  • Check signal status at input terminals H1 and H2.

  • If Safe Disable function is not utilized, terminals H1-HC and H2-HC must be linked.

  • Replace either the control board or the entire drive.
HCA
High Current Alarm
Cause: Drive current exceeded overcurrent warning level (150% of rated current). Load too heavy or ramp too short.


Remedy:

  • Reduce load for applications with repetitive operation.

  • Calculate torque required relative to inertia.

  • Increase acceleration and deceleration times (C1-01 through C1-08).

  • Increase the capacity of the drive.

  • Check motor capacity and ensure it is within allowable range.
LT-1
Cooling Fan Maintenance Time
Cause: The cooling fan has reached 90% of its expected performance life.


Remedy:

  • Replace the cooling fan.

  • Reset the Maintenance Monitor by setting o4-03 to 0.
LT-2
Capacitor Maintenance Time
Cause: The main circuit and control circuit capacitors have reached 90% of their expected performance life.


Remedy:

  • Replace either the control board or the entire drive.

  • Contact Yaskawa or your nearest sales representative.
LT-3
Soft Charge Bypass Relay Maintenance Time
Cause: The DC bus soft charge relay has reached 90% of expected performance life.


Remedy:

  • Replace either the control board or the entire drive.
LT-4
IGBT Maintenance Time (90%)
Cause: IGBTs have reached 90% of their expected performance life.


Remedy:

  • Check the load, carrier frequency, and output speed.

  • Optimize Performance Life: Ensure drive output current does not exceed 150% of rated current.
oH
Heatsink Overheat
Cause: Heatsink temperature exceeded pre-alarm level (L8-02). Surrounding temp too high, fan stopped, or airflow restricted.


Remedy:

  • Check surrounding temperature and improve air circulation.

  • Install a fan or air conditioner to cool the area.

  • Remove anything near the drive causing extra heat.

  • Replace the internal cooling fan if stopped.

  • Clean dust or debris clogging the cooling fan.
oH3
Motor Overheat Alarm (PTC thermistor input)
Cause: Motor overheat signal to A1/A2 exceeded alarm level, wiring fault, or machine locked up.


Remedy:

  • Repair the PTC thermistor input wiring.

  • Check the status of the machine and remove cause of lock-up.

  • Decrease the load or increase accel/decel times.

  • Adjust preset V/f pattern (E1-04 to E1-10).

  • Check motor rated current setting (E2-01).

  • Ensure motor cooling system is operating normally.
oL3
Overtorque Detection 1
Cause: Drive output current/torque greater than L6-02 for time set in L6-03.


Remedy:

  • Check parameters L6-02 and L6-03.

  • Check the status of the machine.

  • Remove the cause of the machine fault (e.g., lock-up).
oL4
Overtorque Detection 2
Cause: Drive output current/torque greater than L6-05 for time set in L6-06.


Remedy:

  • Check parameters L6-05 and L6-06.

  • Check the status of the machine.

  • Remove the cause of the machine fault.
oS
Overspeed (Control Mode with Encoder)
Cause: Motor speed feedback exceeded the F1-08 setting.


Remedy:

  • Check the setting for overspeed detection level and time (F1-08 and F1-09).
ov
DC Bus Overvoltage
Cause: DC bus voltage exceeded trip point (Surge voltage, short-circuit, or noise).


Remedy:

  • Install a DC link choke or AC reactor.

  • Check motor power cable and terminals for short circuits.

  • Correct grounding shorts.

  • Review noise interference solutions (check grounding, install surge protectors).

  • Set number of fault reset (L5-01) to a value other than 0.
PASS
MEMOBUS/Modbus Communication Test Mode Complete
Cause: MEMOBUS/Modbus test has finished normally.


Remedy:

  • This verifies that the test was successful. No action needed.
PGo
Encoder Disconnected
Cause: No encoder signal received for time longer than F1-14 setting. Cable disconnected, wiring wrong, or insufficient power.


Remedy:

  • Reconnect the encoder cable.

  • Correct the wiring.

  • Make sure the correct power supply is connected to the encoder.

  • Ensure the motor brake releases properly.
PGoH
Encoder Disconnected (detected when using encoder)
Cause: Encoder cable has become disconnected.


Remedy:

  • Reconnect the cable.
SE
MEMOBUS/Modbus Self Test Failed
Cause: A digital input set to 67H was closed while the drive was running.


Remedy:

  • Stop the drive and run the test again.
TrPC
IGBT Maintenance Time (90%)
Cause: IGBTs have reached 90% of their expected performance life.


Remedy:

  • Replace the drive.
UL3
Undertorque Detection 1
Cause: Drive output current/torque less than L6-02 for longer than L6-03 time.


Remedy:

  • Check parameters L6-02 and L6-03.

  • Check for broken parts in the transmission system.
UL4
Undertorque Detection 2
Cause: Drive output current/torque less than L6-05 for longer than L6-06 time.


Remedy:

  • Check parameters L6-05 and L6-06.

  • Check for broken parts in the transmission system.
Uv
Undervoltage
Cause: DC bus voltage dropped below level specified in L2-05. Phase loss, loose wiring, or internal circuitry worn.


Remedy:

  • Check for wiring errors in the main circuit drive input power.

  • Ensure terminals are properly tightened (refer to Torque specs).

  • Check the input voltage limits.

  • Check capacitor maintenance time (U4-05).

  • Check input power transformer capacity.

  • Check temperature inside the drive.

  • If CHARGE light is broken, replace control board or drive.
voF
Output Voltage Detection Error
Cause: Hardware is damaged.


Remedy:

  • Replace either the control board or the entire drive.
oPE01
Drive Capacity Setting Fault
Cause: The drive model selection (o2-04) and the actual capacity of the drive are not the same.



Remedy:

  • Correct the value set to o2-04.
oPE02
Parameter Range Setting Error
Cause: Parameters were set outside the possible setting range.



Remedy:

  • Set parameters to the proper values.

  • Use U1-18 to find parameters set outside the range.
oPE03
Multi-function Digital Input Selection Error
Cause: A contradictory setting is assigned to multi-function contact inputs H1-03 to H1-08 (e.g., same function assigned twice, or specific Brake Feedback conflicts).



Remedy:

  • Ensure all multi-function inputs are assigned to different functions.

  • Re-enter the multi-function settings to ensure duplication does not occur.

  • If using Brake Response Monitor (S6-07=1), ensure “Brake feedback 1” (79H) and “Brake feedback 2” (5BH) are assigned correctly to separate terminals.

  • Check for contradictory settings assigned to the multi-function input terminals simultaneously and correct them.
oPE04
Terminal Board Mismatch Error
Cause: The drive, control board, or terminal board has been replaced and the parameter settings between the control board and the terminal board no longer match.



Remedy:

  • To load the parameter settings to the drive that are stored in the terminal board, set A1-03 to 5550.

  • Initialize parameters after drive replacement by setting A1-03 to 1110 or 2220.
oPE05
Reference Source Selection Error
Cause: Speed reference/Up-Down command is assigned to an option card (b1-01/02 = 3) but no card is connected, or Digital card input data length (F3-03) is incorrect for BCD special (F3-01=6).



Remedy:

  • Reconnect the input option card to the drive.

  • Set the input data for 16 bit (F3-03 = 2) if using BCD special 5 digit input.
oPE06
Control Mode Selection Error
Cause: A control mode has been selected that requires a PG option card to be installed, but no option card is installed (A1-02 = 3 or 7).



Remedy:

  • Connect a PG option card.

  • Correct the value set to A1-02.
oPE07
Multi-function Analog Input Selection Error
Cause: At least two analog input terminals are set to the same function (i.e., parameters H3-02 and H3-10 have the same setting).



Remedy:

  • Change the settings to H3-02 and H3-10 so that functions no longer conflict.
oPE08
Parameter Selection Error
Cause: Attempted to use a function not valid for the selected control mode, or n2-02 > n2-03 in Open Loop Vector, or b1-14=1 (Switch phase order) while using a PG option card.



Remedy:

  • Check the motor control method and the functions available.

  • Correct parameter settings so that n2-02 is less than n2-03.

  • Correct the parameter settings for b1-14.
oPE10
V/f Pattern Setting Error
Cause: The V/f pattern frequency settings are incorrect (Logic required: E1-04 ≥ E1-06 ≥ E1-07 ≥ E1-09 ≥ E1-11).



Remedy:

  • Correct the settings for E1-04, E1-06, E1-07, E1-09, and E1-11.

  • For motor 2, correct E3-04, E3-06, E3-07, E3-09, and E3-11.
oPE16
Energy Savings Constants Error
Cause: Energy saving coefficients are out of the allowable range.



Remedy:

  • Check and correct the motor data in E5 parameters.
oPE18
Parameter Setting Error, Online Tuning Parameter Setting Error
Cause: Load cell conflicts (S3-29 = S3-30), Dwell 2 speed logic errors, or Open Loop Vector Online Tuning parameters (E2-02, E2-06, E2-03) are set incorrectly.



Remedy:

  • Correct the values set to S3-29 and S3-30.

  • Correct the values set to S3-20 and S3-21 (Ensure Dwell 2 speed > 0 but < End Speed).

  • Correct the values set to E2-02, E2-03, or/and E2-06.
oPE20
PG-F3 Setting Error
Cause: The encoder signal frequency is too high. With the entered resolution (F1-01) and max output frequency (E1-04), the calculation exceeds 50 kHz (PG-F3) or 20 kHz (PG-E3).



Remedy:

  • Set F1-01 to the correct encoder resolution.

  • Reduce the maximum output frequency of the drive in parameter E1-04.
oPE21
Elevator Parameter Setting Fault
Cause: Elevator parameters are not set correctly (DC Injection time < Brake Close delay, Decel/Stop distances set lower than minimums, or S5-10 and S5-01 enabled simultaneously).



Remedy:

  • Correct parameter settings so that S1-05 > S1-07.

  • Correct parameter settings so that S5-11 > U4-43.

  • Correct parameter settings so that S5-12 > U4-44.

  • Correct the setting in parameters S5-01 and S5-10.
End1
Excessive V/f Setting
Cause: The torque reference exceeded 20% during Auto-Tuning OR the results from Auto-Tuning the no-load current exceeded 80%.



Remedy:

  • Before Auto-Tuning the drive, verify the information written on the motor nameplate and enter that data to T1-03 through T1-05.

  • Enter proper information to parameters T1-03 to T1-05 and repeat Auto-Tuning.
End2
Motor Iron-Core Saturation Coefficient
Cause: Motor data entered during Auto-Tuning was incorrect OR results are outside the parameter setting range.



Remedy:

  • Make sure the data entered to the T1 parameters match the information written on the motor nameplate.

  • Restart Auto-Tuning and enter the correct information.

  • Check and correct faulty motor wiring.
End3
Rated Current Setting Alarm
Cause: The correct current rating printed on the nameplate was not entered into T1-04.



Remedy:

  • Check the setting of parameter T1-04.

  • Check the motor data and repeat Auto-Tuning.
End4
Adjusted Slip Calculation Error
Cause: The slip that was calculated is outside the allowable range.



Remedy:

  • Make sure the data entered for Auto-Tuning is correct.

  • Execute Rotational Auto-Tuning instead. If not possible, try Stationary Auto-Tuning 2.
End5
Resistance Tuning Error
Cause: The resistance value that was calculated is outside the allowable range.



Remedy:

  • Double-check the data that was entered for the Auto-Tuning process.

  • Check the motor and motor cable connection for faults.
End6
Leakage Inductance Alarm
Cause: A1-02 setting error OR the leakage inductance value calculated is outside the allowable range.



Remedy:

  • Check the setting of parameter A1-02.

  • Check the control mode and repeat Auto-Tuning.

  • Double-check the data that was entered for the Auto-Tuning process.
End7
No-Load Current Alarm
Cause: The entered no-load current value was outside the allowable range OR Auto-Tuning results were less than 5% of the motor rated current.



Remedy:

  • Check and correct faulty motor wiring.

  • Double-check the data that was entered for the Auto-Tuning process.
End8
Rescue Operation Speed Warning
Cause: High frequency injection calculations for the battery power supply were below 10 Hz.



Remedy:

  • For Rescue Operation, either switch to a larger battery (at least 280 Vdc for 200V class, 560 Vdc for 400V class, 700 Vdc for 600V class).

  • Or switch to an absolute encoder and the PG-F3 option card.
End9
Rescue Operation Rotor Pole Position Search Warning
Cause: While operating from the backup battery, pole diversion exceeded 40 degrees.



Remedy:

  • For Rescue Operation, either switch to a larger battery.

  • Or switch to an absolute encoder and the PG-F3 option card.
End10
Rescue Operation Rotor Polarity Detection Warning
Cause: While operating from the backup battery, the Id value between poles was less than 5%.



Remedy:

  • For Rescue Operation, either switch to a larger battery.

  • Or switch to an absolute encoder and the PG-F3 option card.
Er-01
Motor Data Error
Cause: Motor data entered incorrect, capacity mismatch, or base freq/speed mismatch.



Remedy:

  • Check that motor data entered to T1 parameters matches motor nameplate.

  • Check drive and motor capacities; correct settings of T1-02 and T1-04.

  • Check motor rated current and no-load current; correct T1-04 and E2-03.

  • Set T1-05 and T1-07 to the correct value. Check pole number (T1-06).
Er-02
Alarm
Cause: An alarm was triggered during Auto-Tuning.



Remedy:

  • Exit the Auto-Tuning menu.

  • Check the alarm code, remove the alarm cause, and repeat Auto-Tuning.
Er-03
STOP Button Input
Cause: Auto-Tuning canceled by pressing STOP button.



Remedy:

  • Auto-Tuning did not complete properly and will have to be performed again.
Er-04
Line-to-Line Resistance Error
Cause: Motor data incorrect, result out of range, or cable fault.



Remedy:

  • Make sure T1 parameters match motor nameplate.

  • Check and correct faulty motor wiring.
Er-05
No-Load Current Error
Cause: Motor data incorrect, result out of range, or load too high during tuning.



Remedy:

  • Make sure T1 parameters match motor nameplate.

  • Check and correct faulty motor wiring.

  • Perform Rotational Auto-Tuning. Ensure rope is removed and brake is released.

  • Disconnect motor from machine if load > 30% or verify mechanical brake is lifted.
Er-08
Rated Slip Error
Cause: Data incorrect, calculation timed out, or load too high.



Remedy:

  • Match T1 parameters to nameplate.

  • Check and correct faulty motor wiring.

  • Disconnect motor from machine if load > 30%.

  • Ensure mechanical brake is fully lifted.
Er-09
Acceleration Error
Cause: Motor did not accelerate (ramp too short), torque limit too low, or load too high.



Remedy:

  • Lengthen acceleration ramp (C1-01).

  • Increase setting of L7-01 and L7-02.

  • Disconnect motor from machine or ensure brake is lifted.
Er-10
Motor Direction Error
Cause: Encoder lines not connected properly, Motor/PG direction opposite, or load pulled motor.



Remedy:

  • Check and correct wiring to the PG encoder.

  • Check motor speed monitor U1-05 while turning manually forward. If negative, change F1-05.

  • Uncouple the motor from the load and repeat Auto-Tuning.
Er-11
Motor Speed Fault
Cause: Torque reference is too high.



Remedy:

  • Lengthen the acceleration ramp set to C1-01.

  • Disconnect the machine from the motor, if possible.
Er-12
Current Detection Error
Cause: Phase missing, current too high/low, or signal error.



Remedy:

  • Check motor wiring for short or disconnection.

  • Ensure motor contactor is closed.

  • Connect the motor if attempting tuning without it.

  • Replace control board or drive if hardware error persists.
Er-13
Leakage Inductance Error
Cause: Unable to complete tuning within 300 seconds.



Remedy:

  • Check all wiring and correct any mistakes.

  • Double-check motor rated current entered to T1-04.
Er-18
Induction Voltage Error
Cause: Induced voltage constant outside allowable range.



Remedy:

  • Double-check the data entered to the T2 parameters and perform Auto-Tuning again.
Er-19
Inductance Error
Cause: Induced voltage constant attempted to set value to E5-08 or E5-09 outside range.



Remedy:

  • Double-check the data entered to the T2 parameters and perform Auto-Tuning again.
Er-20
Stator Resistance Error
Cause: Attempted to set E5-06 outside allowable range.



Remedy:

  • Double-check the data entered to the T2 parameters and perform Auto-Tuning again.
Er-21
Z Pulse Correction Error
Cause: Motor coasting, wiring issue, encoder direction/pulses wrong, encoder damaged, or PG-E3 error.



Remedy:

  • Make sure motor has stopped completely.

  • Check wiring for motor and encoder.

  • Check direction setting (F1-05/b1-14) and pulse count (F1-01).

  • Check signal output from encoder; replace if damaged.

  • Perform Auto-Tuning of PG-E3 encoder characteristics.
Er-22
Initial Rotor Pole Search Error
Cause: Parameters outside range or pole diversion exceeded 20 degrees.



Remedy:

  • Switch to an absolute encoder and to the PG-F3 option card.
Er-23
Non-rotating Encoder Offset Tuning Warning
Cause: Pole diversion exceeded 15 degrees three times.



Remedy:

  • Remove the ropes and conduct Rotational Auto-Tuning for Encoder Offset (T2-01 = 3).
Er-24
Auto-Tuning Error for PG-E3 Encoder Characteristics
Cause: Signal lines disconnected, electrical interference, or unsupported software version.



Remedy:

  • Refer to PG-E3 installation manual for correct connection.

  • Check software version (PRG) for PG-E3 (needs 1102 or later).
CoPy

Writing Parameter Settings (flashing)
Cause: Parameters are being written to the drive.



Remedy:


Not an error.
CPEr

Control Mode Mismatch
Cause: Control mode of the parameters to be loaded onto the drive and the control mode already set to the drive don’t match.



Remedy:


Check the control mode for the parameters that are to be loaded onto the drive and the control mode set to the drive those parameters will be written to. Set the same control mode using parameter A1-02 and try again.
CPyE

Error Writing Data
Cause: Failed writing parameters.



Remedy:


Try writing parameters again.
CSEr

Copy Unit Error
Cause: Hardware fault.



Remedy:


Replace the operator or the USB Copy Unit.
dFPS

Drive Model Mismatch
Cause:

  • The drives used in the copy and write process are not the same model.

  • The drive from which the parameters were copied is a different model.

  • The drive to be written to is a different model.




Remedy:


Check the model number of the drive from which the parameters were copied and the model of the drive to which you are attempting to write the parameters. Make sure the two drives are the same model and have the same software version.
ECE

Copy Error
Cause: Attempted to read data from the encoder during undervoltage.



Remedy:


Make sure there is no undervoltage fault or alarm, then try reading the data again.
ECS

Checksum Error
Cause: Checksum error occurred when attempting to read data from the encoder.



Remedy:


Try copying the data again.
EdE

Write Impossible
Cause: Drive settings do not permit writing to the encoder (F1-51 = 0), or there was a CPF24 while attempting to write to the encoder.



Remedy:


Set the drive to allow encoder to be written to (F1-51 = 1) and try writing the data again.
EiF

Write Data Error
Cause: Communication error occurred while attempting to write to the encoder.



Remedy:


Make sure communications are normal and try writing to the encoder again.
End

Task Complete
Cause: Finished reading, writing, or verifying parameters.



Remedy:


Not an error.
EPE

ID Mismatch
Cause: Attempted to acquire machine data from an encoder that does not have any machine data written to it yet.



Remedy:


Try again after writing machine data to the encoder.
ErE

Data Error
Cause: Attempted to write data to the encoder during undervoltage.



Remedy:


Make sure there is no undervoltage fault or alarm and try again.
EvE

Verify Error
Cause: Drive parameters and the data saved to the encoder do not match.



Remedy:


Use the Verify Menu to check parameter settings and try again.
iFEr

Communication Error
Cause:

  • A communication error occurred between the drive and the operator or the USB copy unit.

  • A non-compatible cable is being used to connect the USB Copy Unit and the drive.




Remedy:



  • Check the cable connection.

  • Use the cable originally packaged with the USB Copy Unit.
ndAT

Model, Voltage Class, Capacity Mismatch
Cause:

  • The drive from which the parameters were copied and the drive to which you are attempting to write have different electrical specifications, capacities, are set to different control modes, or are different models.

  • The device being used to write the parameters is blank and does not have any parameters saved on it.




Remedy:



  • Make sure model numbers and specifications are the same for both drives.

  • Make sure all connections are correct, and copy the parameter settings onto the USB Copy Unit or the operator.
rdEr

Error Reading Data
Cause: Failed while attempting to read parameter settings from the drive.



Remedy:


Press and hold the READ key on the USB Copy Unit for at least one second to have the unit read parameters from the drive.
rEAd

Reading Parameter Settings (flashing)
Cause: Displayed while the parameter settings are being read onto the USB Copy Unit.



Remedy:


Not an error.
vAEr

Voltage Class, Capacity Mismatch
Cause: The drive the parameters were copied from and the drive you performing the Verify mode on have different electrical specifications or are a different capacity.



Remedy:


Make sure electrical specifications and capacities are the same for both drives.
vFyE

Parameter settings in the drive and those saved to the copy function are not the same
Cause: Indicates that parameter settings that have been Read and loaded onto the Copy Unit or Digital Operator are different.



Remedy:


To synchronize parameters, either write the parameters saved on the USB Copy Unit or LCD digital operator onto the drive, or Read the parameter settings on the drive onto the USB Copy Unit.
vrFy

Comparing Parameter Settings (flashing)
Cause: The Verify mode has confirmed that parameters settings on the drive and parameters read to the copy device are identical.



Remedy:


Not an error.