KEB fault codes & error messages
Enter your code in the search to decode the message of your KEB frequency inverter – with a description and concrete instructions for remedying it.
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Spelling does not matter: E.OP, EOP or e op lead to the same result.
61 messages
Mains & DC link8
E.UP Undervoltage Diagnosis recommended
Message
Value
Description
Recommended action
E.UP
–
The DC link voltage has fallen below the permissible minimum value.
Measure mains voltage and back-up fuses. Rule out voltage dips and mains failures during operation, check the cable cross-section.
E.OP Overvoltage Diagnosis recommended
Message
Value
Description
Recommended action
E.OP
–
The DC link voltage has exceeded the permissible maximum value.
Extend the deceleration ramp. Check or provide a braking resistor or braking module. Measure the mains voltage for overvoltage.
E.LSF Charging circuit / charging relay Repair likely
Message
Value
Description
Recommended action
E.LSF
–
The DC link charging circuit did not switch correctly.
Disconnect the unit completely from the power supply and switch it on again. If the message persists, the power unit is defective – repair required.
E.ncl DC link not charged Diagnosis recommended
Message
Value
Description
Recommended action
E.ncl
–
Release was given without the DC link being charged.
Apply mains voltage and wait for charging. In composite operation, check the sequence of mains and release signal.
E.PL Mains phase failure Diagnosis recommended
Message
Value
Description
Recommended action
E.PL
–
Failure or severe imbalance of a mains phase detected.
Check back-up fuses, mains contactor and terminal connections of all three phases.
A.OP Warning overvoltage Can be checked yourself
Message
Value
Description
Recommended action
A.OP
–
The DC link voltage is approaching the shutdown threshold.
Extend the deceleration ramp or increase braking power before the unit switches off.
Does the fault persist after checking?
Have your KEB unit checked →
A.UP Warning undervoltage Can be checked yourself
Message
Value
Description
Recommended action
A.UP
–
The DC link voltage is approaching the minimum value.
Check mains quality; stagger load peaks and the simultaneous starting of several drives.
Does the fault persist after checking?
Have your KEB unit checked →
A.ncl Warning charging state Can be checked yourself
Message
Value
Description
Recommended action
A.ncl
–
The DC link is not yet fully charged.
Wait for charging to complete, only then give the release.
Does the fault persist after checking?
Have your KEB unit checked →
Temperature & cooling8
E.OH Overtemperature heat sink Diagnosis recommended
Message
Value
Description
Recommended action
E.OH
–
The heat sink temperature has exceeded the limit value.
Clean fans and air paths, replace filter mats. Lower the ambient temperature, check mounting clearances and control cabinet ventilation.
E.OHI Overtemperature internal Diagnosis recommended
Message
Value
Description
Recommended action
E.OHI
–
The internal temperature of the unit is too high.
Check control cabinet ventilation and unit fans; reduce heat sources inside the cabinet.
E.dOH Motor protection tripped Diagnosis recommended
Message
Value
Description
Recommended action
E.dOH
–
The thermal motor protection has switched off.
Check motor cooling and load. Verify motor data and tripping threshold in the inverter, check the forced-ventilation fan.
E.OHb Overtemperature braking resistor Diagnosis recommended
Message
Value
Description
Recommended action
E.OHb
–
The braking resistor has reached its thermal limit.
Reduce braking cycles or use a resistor with higher continuous rating; check connection and ventilation.
A.OH Warning heat sink temperature Can be checked yourself
Message
Value
Description
Recommended action
A.OH
–
The heat sink temperature is approaching the limit value.
Improve cooling before shutdown occurs: check fans, filters and ambient temperature.
Does the fault persist after checking?
Have your KEB unit checked →
A.OHI Warning internal temperature Can be checked yourself
Message
Value
Description
Recommended action
A.OHI
–
The internal temperature is approaching the limit value.
Increase cabinet ventilation, check the unit fans.
Does the fault persist after checking?
Have your KEB unit checked →
A.dOH Warning motor temperature Can be checked yourself
Message
Value
Description
Recommended action
A.dOH
–
The calculated motor temperature is approaching the tripping threshold.
Reduce continuous load, check motor cooling.
Does the fault persist after checking?
Have your KEB unit checked →
A.OHb Warning braking resistor Can be checked yourself
Message
Value
Description
Recommended action
A.OHb
–
The braking resistor is approaching its thermal limit.
Reduce braking cycles, check the rating of the resistor.
Does the fault persist after checking?
Have your KEB unit checked →
Current, load & drive9
E.OC Overcurrent Diagnosis recommended
Message
Value
Description
Recommended action
E.OC
–
The output current has exceeded the permissible peak value.
Check the motor cable for short circuit and earth fault. Extend the acceleration ramp, reduce boost, verify motor assignment and power rating.
E.OL Overload Diagnosis recommended
Message
Value
Description
Recommended action
E.OL
–
The permissible overload time of the inverter has elapsed.
Reduce the load mechanically, extend the ramps or use a unit with higher rating. Wait for the cool-down time.
E.OL2 Overload at standstill Diagnosis recommended
Message
Value
Description
Recommended action
E.OL2
–
Overload at low output frequency or at standstill.
Reduce holding torque, use a mechanical brake, limit operation at low speed.
E.OS Overspeed Diagnosis recommended
Message
Value
Description
Recommended action
E.OS
–
The permissible maximum speed has been exceeded.
Check control parameters and speed limits; verify encoder signal and gear ratio; take overhauling loads into account.
E.dri Driver stage / control Repair likely
Message
Value
Description
Recommended action
E.dri
–
Fault in the driver supply of the power output stage.
Disconnect the unit from the power supply and restart it. If the message reappears, there is a defect – repair required.
E.br Braking circuit / braking transistor Repair likely
Message
Value
Description
Recommended action
E.br
–
Fault in the braking circuit or at the braking transistor.
Check the braking resistor and its supply line for open circuit and short circuit. If the output stage is defective, repair is required.
A.OL Warning overload Can be checked yourself
Message
Value
Description
Recommended action
A.OL
–
The inverter is operating continuously in the overload range.
Reduce the load or use an inverter with higher rating.
Does the fault persist after checking?
Have your KEB unit checked →
A.OL2 Warning standstill load Can be checked yourself
Message
Value
Description
Recommended action
A.OL2
–
High load at low speed or at standstill.
Shorten holding times, use a mechanical brake.
Does the fault persist after checking?
Have your KEB unit checked →
A.nOL Overload ended Can be checked yourself
Message
Value
Description
Recommended action
A.nOL
–
The overload condition has ended, the cool-down time is running.
After the cool-down time has elapsed, the drive can be fully loaded again.
Does the fault persist after checking?
Have your KEB unit checked →
Power unit & hardware7
E.PU Power unit fault Repair likely
Message
Value
Description
Recommended action
E.PU
–
The power unit reports an internal fault.
Disconnect the unit from the power supply and restart it. If the message persists, an inspection by a specialist is required.
E.PUc Power unit identification Repair likely
Message
Value
Description
Recommended action
E.PUc
–
The identification of the power unit could not be read or assigned.
Check that control unit and power unit belong together; verify the plug connections.
E.PUCH Power unit changed Repair likely
Message
Value
Description
Recommended action
E.PUCH
–
A different power unit was detected than the one previously stored.
Confirm the combination or adapt the parameter set to the unit.
E.EEP Memory error (EEPROM) Repair likely
Message
Value
Description
Recommended action
E.EEP
–
Read or write error in the non-volatile memory.
Load the factory setting and re-parameterise. If the fault recurs, the control card must be checked.
E.Hyb Hybrid / option module Diagnosis recommended
Message
Value
Description
Recommended action
E.Hyb
–
Fault at the plugged-in option or hybrid module.
Check module and plug connection, re-plug the module; match the module type with the parameter settings.
E.HybC Option module changed Diagnosis recommended
Message
Value
Description
Recommended action
E.HybC
–
A different option module was detected than the one stored.
Confirm the module change or install the original module.
E.iEd Internal communication fault Repair likely
Message
Value
Description
Recommended action
E.iEd
–
Disturbance of the internal communication between control unit and power unit.
Check interference and shielding, restart the unit; if the fault persists, arrange for repair.
Encoder & feedback4
E.EnC Encoder fault Diagnosis recommended
Message
Value
Description
Recommended action
E.EnC
–
The speed encoder signal is disturbed or missing.
Check encoder cable, shielding and plug connection. Verify encoder type and pulse count in the parameter settings.
E.EnCC Encoder communication Diagnosis recommended
Message
Value
Description
Recommended action
E.EnCC
–
Communication with the serial encoder is interrupted.
Check cable routing and connection; check the encoder for defects.
E.SPL Encoder track monitoring Diagnosis recommended
Message
Value
Description
Recommended action
E.SPL
–
Implausible or missing encoder tracks detected.
Check the wiring of tracks A/B, verify the mechanical coupling of the encoder.
E.cS Speed control fault Diagnosis recommended
Message
Value
Description
Recommended action
E.cS
–
The speed control could not reach the setpoint.
Check controller parameters and motor data, reduce load steps, verify the encoder assignment.
Communication & control5
E.buS Bus fault / watchdog Diagnosis recommended
Message
Value
Description
Recommended action
E.buS
–
The connection to the higher-level control system is interrupted.
Check bus cable, terminating resistors and shielding. Verify addressing, baud rate and watchdog time.
E.EF External fault Can be checked yourself
Message
Value
Description
Recommended action
E.EF
–
An external fault signal was triggered at the fault input.
Check external interlock, protective devices and connected equipment.
Does the fault persist after checking?
Have your KEB unit checked →
E.SbuS System bus Diagnosis recommended
Message
Value
Description
Recommended action
E.SbuS
–
Disturbance of the system bus communication between several units.
Check cabling, termination and node addresses in the system bus.
E.co1 Counter overflow 1 Diagnosis recommended
Message
Value
Description
Recommended action
E.co1
–
An internal counter or position range has overflowed.
Adjust the position range and gear ratio, reset the counter after homing.
E.co2 Counter overflow 2 Diagnosis recommended
Message
Value
Description
Recommended action
E.co2
–
The second internal counter has overflowed.
Check the position specifications and carry out referencing again.
Parameters, software & positioning8
E.SET Parameter set fault Can be checked yourself
Message
Value
Description
Recommended action
E.SET
–
The selected parameter set is invalid or does not exist.
Check the parameter set selection, transfer the set again or load the factory setting.
Does the fault persist after checking?
Have your KEB unit checked →
E.Cdd Copy / calculate data set Diagnosis recommended
Message
Value
Description
Recommended action
E.Cdd
–
Fault while copying or calculating a data set.
Repeat the copying process, enter the motor data completely and restart the calculation.
E.PrF Homing run Can be checked yourself
Message
Value
Description
Recommended action
E.PrF
–
The homing run was not completed correctly.
Check the reference switch and direction of travel, restart the homing run.
Does the fault persist after checking?
Have your KEB unit checked →
E.SLF Software limit switch forward Can be checked yourself
Message
Value
Description
Recommended action
E.SLF
–
The software limit switch in forward direction has been reached.
Move the position back into the valid range; check limit values and target positions.
Does the fault persist after checking?
Have your KEB unit checked →
E.SLr Software limit switch reverse Can be checked yourself
Message
Value
Description
Recommended action
E.SLr
–
The software limit switch in reverse direction has been reached.
Move the position back; check limit values and reference point.
Does the fault persist after checking?
Have your KEB unit checked →
E.HLF Hardware limit switch forward Can be checked yourself
Message
Value
Description
Recommended action
E.HLF
–
The hardware limit switch in forward direction has tripped.
Move the drive clear, check limit switches and wiring.
Does the fault persist after checking?
Have your KEB unit checked →
E.HLr Hardware limit switch reverse Can be checked yourself
Message
Value
Description
Recommended action
E.HLr
–
The hardware limit switch in reverse direction has tripped.
Move the drive clear, check limit switches and wiring.
Does the fault persist after checking?
Have your KEB unit checked →
A.PrF Warning homing run Can be checked yourself
Message
Value
Description
Recommended action
A.PrF
–
Homing run required or not yet completed.
Carry out a homing run before starting positioning jobs.
Does the fault persist after checking?
Have your KEB unit checked →
Status & operating messages12
S.nOP No release Operating state
Message
Value
Description
Recommended action
S.nOP
–
The unit is ready for operation, the control release is missing.
Apply the release signal at the control terminal; check wiring and safety circuit.
S.rdy Ready for operation Operating state
Message
Value
Description
Recommended action
S.rdy
–
Unit ready for operation, no message pending.
No action required.
S.LS Modulation disabled Operating state
Message
Value
Description
Recommended action
S.LS
–
The output stage is disabled, the motor is torque-free.
Check release and setpoint specification.
S.bASE Output stage disabled Operating state
Message
Value
Description
Recommended action
S.bASE
–
External output stage disable is active.
Check the disable signal and the safety function.
S.FAcc Acceleration forward Operating state
Message
Value
Description
Recommended action
S.FAcc
–
The drive is accelerating in forward direction.
Operating message – no action required.
S.FdEc Deceleration forward Operating state
Message
Value
Description
Recommended action
S.FdEc
–
The drive is decelerating in forward direction.
Operating message – no action required.
S.Fcon Constant travel forward Operating state
Message
Value
Description
Recommended action
S.Fcon
–
The drive is running forward at constant speed.
Operating message – no action required.
S.rAcc Acceleration reverse Operating state
Message
Value
Description
Recommended action
S.rAcc
–
The drive is accelerating in reverse direction.
Operating message – no action required.
S.rdEc Deceleration reverse Operating state
Message
Value
Description
Recommended action
S.rdEc
–
The drive is decelerating in reverse direction.
Operating message – no action required.
S.rcon Constant travel reverse Operating state
Message
Value
Description
Recommended action
S.rcon
–
The drive is running in reverse at constant speed.
Operating message – no action required.
S.cAlc Calculation running Operating state
Message
Value
Description
Recommended action
S.cAlc
–
The unit is calculating internal motor and controller data.
Wait for the process to finish, do not switch off the unit meanwhile.
S.dcb DC braking Operating state
Message
Value
Description
Recommended action
S.dcb
–
DC braking is active.
Operating message – adjust braking time and braking current if required.
Fault code not found?
KEB fault codes differ depending on series and firmware. Photograph the display and the type plate – we will identify unit and message for you.
KEB repair at ISA Drive
As an official KEB partner we repair frequency inverters of every series – from fault analysis to final testing.
- Fault analysis by technicians with over 25 years of practical experience
- Transparent cost estimate before every repair
- Repair and documented final testing
- One-year warranty on the repair work
Questions about the diagnosis?
Our technicians help you interpret your KEB message.
05262 99104Mon–Fri · 7:00 a.m. to 4:00 p.m.
To KEB repair & service →