3
Earth Fault
Vacon · NX Liquid-Cooled Drive
What does 3 mean?
The current measurement system has detected that the sum of the motor phase currents is not zero, indicating a leakage current to ground. This fault is most commonly caused by insulation failure in the motor cables or within the motor windings themselves.
Source: Vacon NX Liquid-Cooled Drive
Open Manual (Page 151)