invt fault codes
INVT VFD Fault Codes and Troubleshooting
Before troubleshooting an INVT variable frequency drive (VFD), make sure all safety precautions for the relevant drive model have been followed. Maintenance and electrical work should only be performed by qualified electrical personnel.
When the TRIP indicator is active, the message shown on the keypad identifies an abnormal drive condition. The fault code, operating conditions and recorded parameters should be checked before the drive is reset.
If the problem cannot be resolved, please use the INVT contact and technical support page.
How to Reset an INVT VFD Fault
After the cause of the fault has been removed, the drive can be reset by pressing STOP/RST, using an assigned digital input or, when appropriate, switching the power off and on. Do not restart the motor until the cause of the fault has been identified and corrected.
Basic Fault-Checking Procedure
1. Check the keypad and its connection.
2. Check the P07 fault records and compare the stored operating data with the actual machine conditions.
3. Find the relevant fault code below and inspect the listed possible causes.
4. Correct the actual cause of the fault.
5. Reset the drive only after confirming that the fault condition has been removed.
OUt1 / OUt2 / OUt3 - IGBT Phase Faults
OUt1 - IGBT U-phase fault
OUt2 - IGBT V-phase fault
OUt3 - IGBT W-phase fault
Possible causes:
1. Acceleration time is too short.
2. The IGBT module may be damaged.
3. Electrical interference may cause incorrect operation.
4. Motor or drive wiring may be loose or incorrect.
5. A short circuit to ground may be present.
Checks and solutions:
Increase the acceleration time. Check the power unit and motor wiring. Inspect the motor and output circuit for a ground fault and check for strong interference from nearby equipment.
OC1 / OC2 / OC3 - Overcurrent Faults
OC1 - Overcurrent during acceleration
OC2 - Overcurrent during deceleration
OC3 - Overcurrent at constant speed
Possible causes:
1. Acceleration or deceleration is too fast.
2. Mains voltage is too low.
3. VFD capacity is too small for the load.
4. Load changes are excessive or abnormal.
5. A ground fault, phase-to-phase short circuit or output phase loss is present.
6. Strong external interference exists.
7. Related stall-protection parameters may be incorrectly configured.
Checks and solutions:
Increase the acceleration or deceleration time. Check the input supply. Verify that the VFD capacity is sufficient. Inspect the motor and load for ground or line-to-line short circuits. Check output wiring and related function-code settings.
OV1 / OV2 / OV3 - Overvoltage Faults
OV1 - Overvoltage during acceleration
OV2 - Overvoltage during deceleration
OV3 - Overvoltage at constant speed
Possible causes:
1. Input voltage is too high or abnormal.
2. Regenerative energy returned from the motor is excessive.
3. Required braking components are not installed or enabled.
4. Deceleration time is too short.
Checks and solutions:
Check the incoming supply voltage. Increase the deceleration time where necessary. If the application produces high regenerative energy, inspect the braking circuit and install a suitable braking resistor or braking unit where required.
For additional information about braking principles, see DC braking.
UV - DC Bus Undervoltage
Cause:
The DC-bus or power-supply voltage is too low.
Solution:
Check the mains input voltage, power supply and incoming connections.
OL1 - Motor Overload
Possible causes:
1. Supply voltage is too low.
2. The motor rated-current parameter is incorrect.
3. The motor is stalled or the load changes are excessive.
Checks and solutions:
Check the mains supply and protection devices. Enter the correct motor rated current and inspect the mechanical load. Check the torque boost / torque control settings where applicable.
OL2 - VFD Overload
Possible causes:
1. Acceleration is too fast.
2. The drive is attempting to restart a rotating motor.
3. Mains voltage is too low.
4. The load is too heavy.
5. The motor and drive power ratings may not be suitable for the application.
Checks and solutions:
Increase acceleration time. Avoid immediate restart while the motor is still rotating. Check the supply voltage and select a VFD and motor with suitable capacity for the load.
OL3 - Electrical Overload
The VFD issues an overload pre-alarm according to the configured protection value.
Solution:
Check the mechanical load and the configured overload pre-alarm threshold.
SPI - Input Phase Loss
Possible cause:
One of the R, S or T input phases may be missing or the incoming supply may be severely unbalanced.
Checks and solutions:
Check the incoming supply, DC-bus condition and input wiring.
SPO - Output Phase Loss
Possible cause:
A U, V or W output phase may be missing, or the three-phase motor load may be severely unbalanced.
Checks and solutions:
Check the VFD output wiring, motor cable and motor windings.
OH1 / OH2 - Overtemperature Faults
OH1 - Rectifier overtemperature
OH2 - IGBT overtemperature
Possible causes:
1. The cooling air duct is blocked or the fan is damaged.
2. Ambient temperature is too high.
3. The drive has operated under overload for too long.
Checks and solutions:
Inspect and clean the cooling path. Check the cooling fan. Reduce the ambient temperature. Check the power connections and investigate any persistent overcurrent or overload condition.
EF - External Fault
A digital input assigned to the external-fault function has become active.
Solution:
Check the external device and the digital input assigned to the external-fault function.
CE - Communication Error
Possible causes:
1. Baud-rate setting is incorrect.
2. Communication wiring or interface is faulty.
3. The communication address is incorrect.
4. Strong electromagnetic interference is affecting communication.
Checks and solutions:
Set the correct baud rate and device address. Check the communication interface and cable. Improve cable routing, shielding and grounding to reduce electrical interference.
ItE - Current Detection Fault
Possible causes:
1. Control-board connections are poor.
2. The auxiliary internal power supply may be faulty.
3. The Hall current-sensing device may be damaged.
4. The current-detection amplifier circuit may be abnormal.
Checks and solutions:
Check connectors and internal wiring. Inspect the Hall current sensor and control board. Replace defective components where necessary.
tE - Autotuning Fault
Possible causes:
1. Motor capacity does not match VFD capacity.
2. Motor rated parameters are incorrect.
3. Values identified during autotuning differ significantly from expected motor data.
4. Autotuning has timed out.
Checks and solutions:
Verify drive and motor sizing. Enter the motor nameplate values correctly. Remove the mechanical load where the selected tuning procedure requires it and repeat autotuning. Check motor wiring and make sure the upper frequency limit is above two-thirds of the motor rated frequency.
EEP - EEPROM Fault
Possible causes:
1. A parameter read/write error has occurred.
2. EEPROM memory may be damaged.
Checks and solutions:
Press STOP/RST to attempt a reset. If the fault persists, the main control board may require service or replacement.
PIDE - PID Feedback Fault
Possible causes:
1. PID feedback signal is disconnected.
2. The PID feedback source is missing or faulty.
Checks and solutions:
Check the PID feedback signal, sensor wiring and feedback source.
bCE - Braking Unit Fault
Possible causes:
1. The braking circuit or braking transistor may be faulty.
2. The external braking resistor may have insufficient capacity.
Checks and solutions:
Check the braking unit. Inspect the braking transistor/circuit and verify that the braking resistor has the correct resistance and power rating.
END - Running-Time Limit Reached
The accumulated operating time of the VFD has exceeded the configured running-time limit.
Solution:
Check and, where appropriate, adjust the configured running-time parameter.
PCE - Keypad Communication Error
Possible causes:
1. The keypad connection is loose or disconnected.
2. The keypad cable is too long or exposed to strong interference.
3. The keypad or main-board communication circuit may be faulty.
Checks and solutions:
Check the keypad cable and connectors. Reduce interference sources. If the fault remains, inspect the keypad and control-board hardware.
UPE - Parameter Upload Error
Possible causes:
1. Keypad connection is poor or offline.
2. Keypad cable is too long or exposed to strong interference.
3. A fault may exist in the keypad or main-board communication circuit.
Checks and solutions:
Check the keypad connection and communication cable. Eliminate nearby interference sources. If necessary, inspect or replace the faulty hardware.
DNE - Parameter Download Error
Possible causes:
1. Keypad connection is poor or offline.
2. The keypad cable is too long or exposed to strong electromagnetic interference.
3. A data-storage error exists in the keypad.
Checks and solutions:
Check the keypad cable and remove interference sources. Inspect the hardware and back up or rewrite the keypad data if required.
ETH1 / ETH2 - Ground Short-Circuit Fault
ETH1 - Ground short-circuit fault 1
ETH2 - Ground short-circuit fault 2
Possible causes:
1. VFD output is short-circuited to ground.
2. The current-detection circuit may be faulty.
3. The configured motor power may differ significantly from the actual motor rating.
Checks and solutions:
Check the motor and U-V-W output wiring for a ground fault. Inspect the Hall current sensor and control board. Verify that the motor parameters in the P2 group match the actual motor nameplate data.
LL - Electronic Underload Fault
The VFD issues an underload pre-alarm according to the configured value.
Solution:
Check the mechanical load and the configured underload pre-alarm threshold.
STO / STL1 / STL2 / STL3 - Safe Torque Off Status and Faults
STO - Safe Torque Off function active / normal STO operation
STL1 - H1 channel abnormal
A fault may exist in the H1 input channel or its internal safety circuit.
STL2 - H2 channel abnormal
A fault may exist in the H2 input channel or its internal safety circuit.
STL3 - Internal safety circuit abnormal
A simultaneous fault may exist in both H1 and H2 safety channels.
Checks and solutions:
Check the STO safety inputs, switch and associated wiring. Replace the STO switch if faulty. If the problem remains, contact qualified service personnel or the manufacturer.
CrCE - Safety Code CRC Fault
Cause:
An error has occurred during the FLASH CRC check of the STO safety code.
Solution:
Contact qualified service personnel or the manufacturer.
PoFF - System Power Off
Possible cause:
System power is off or the DC-bus voltage is too low.
Solution:
Check the mains supply and DC-bus conditions.
Related INVT Pages
+ INVT User Manuals and Technical Documents
+ INVT Commissioning and Application Notes