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What are the probable causes and remedies of tnF (Autotuning Fault in Altivar 71)

This fault appears only if a TUNE (Autotuning) has been requested.

Autotuning Preparation:


The motor must be de-fluxed before beginning a tune.

Note:
a.) On a synchronous motor only the Stator Resistance is measured.
b.) For asynchronous motor both the Stator Resistance and Leakage Inductance are measured.
 
Probable Causes:
 
1.) Special motor or a motor power that is not within the range of the Drive.
2.) Motor not connected to the Drive.
3.) Tuning with long motor cable and output filter.
 
Remedies:

1.) Make sure the motor is connected during the Autotuning process.
2.) Check the size of the motor compared to the Drive.
3.) If the output contactor is present ensure that it is closed during Autotuning.
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