KEB F4 Inverter Debugging Guide

This mode can provide great convenience when testing the motor steering, no-load test run and troubleshooting the given signal fault of the upper computer.

Chapter 5: Practical Fault Diagnosis - Cracking Difficulties such as E.OC and E.OL

When the frequency converter alarms, the operation panel will display a code starting with "E.". Understanding the underlying reasons and quickly locating them is a reflection of an engineer's professional ability.

Original description of fault code: deep causes and engineering troubleshooting path

E. Reasons for undervoltage in UV intermediate circuit: low input voltage, instantaneous drop of power grid, large voltage drop caused by thin wire diameter, or damage to rectifier bridge.

Countermeasure: Measure the input voltage; Check the voltage drop of the circuit; Extend the acceleration and deceleration time to reduce the voltage pumping demand caused by energy feedback.

E. Reasons for overvoltage in OV intermediate circuit: Rapid deceleration leading to motor regenerative energy backflow, high input voltage, or disconnected or damaged braking unit/braking resistor.

Countermeasure: Extend deceleration time (CP.8); Install and inspect the wiring of the braking resistor; Use a voltmeter to monitor the peak value of the power grid.

E. OC overcurrent or ground short circuit cause: This is one of the more common faults. Usually caused by motor insulation damage, cable skin breakage, IGBT module breakdown of frequency converter, or short acceleration time.

Countermeasure: Disconnect the motor cable to determine whether it is a problem with the frequency converter or the motor; Shake test motor insulation; Check if CP.14 is set excessively.

E. Reason for overload of OL frequency converter: mechanical jamming of the load, motor stalling, or selection of a smaller frequency converter. Interestingly, after the fault shutdown, the frequency converter will enter the cooling timer, during which a waiting message will be displayed. It can only be reset after the cooling is completed.

Countermeasure: Check the mechanical load; Use a clamp current meter to measure the actual current compared to the rated current.

E. Reasons for overheating of OH/E.dOH frequency converter/motor: high ambient temperature, blocked/damaged fan, blocked air duct, or long-term low-speed high current operation of the motor.

Countermeasure: Clean the heat sink and fan; Check the wiring of the PTC thermistor of the motor (connected to the OH terminal); Add ventilation inside the control cabinet.

Note: The original text specifically reminds that after the E.OH and E.dOH errors are eliminated, the system will not automatically reset and needs to be manually reset.

Chapter 6: Security and Password Protection - Barriers to Prevent Misconduct

To prevent unauthorized parameter modification, F4 supports password protection function. No password in factory state, all parameters can be read and written.

Set password: Enter a number from 1 to 9999 through CP.0 to set it as the password.

Parameter read-only mode: After password verification, if a lock operation is performed on a specific interface, the CP parameter will become read-only and cannot be modified.

Release: Enter the correct password again to unlock. After the debugging is completed and delivered to the site, it can effectively protect key parameters from being mistakenly modified.