Two windings from different phases are shorted together through two resistors Rfa and Rfb, and the mid point is grounded through Rfg. A type 2 fault is when the mid point remains ungrounded, i.e., Rfg stays very large during the fault, while a type 3 implies very small values for all three resistors for the duration of the fault. These two types of stator internal faults are treated together since they affect the winding functions the same way. As illustrated by the figure below, both faulty windings are treated as an upper and lower part separated by the fault point.
![Type 2 and 3 Fault in a Synchronous Machine with Two Parallel Windings and Neutral Impedance Type 2 and 3 Fault in a Synchronous Machine with Two Parallel Windings and Neutral Impedance](https://opal-rt.atlassian.net/wiki/download/thumbnails/150245619/SMwith2ParallelWindingsNeutralImp.png?version=1&modificationDate=1688602104844&cacheVersion=1&api=v2&width=450&height=227)
Type 2 and 3 Fault in a Synchronous Machine with Two Parallel Windings and Neutral Impedance