Impregnant is not always at fault
In some cases, during impregnation of electrical machine parts, sometimes winding terminals are dipped and then cured. In subsequent bending
... the insulation of these conductors can rarely crack. As a result, inhomogeneities in material composition were revealed by detailed analysis of thus cracked conductors. Impregnant penetrates into the pores of the insulation, causing cracking after curing. The solution to this problem was the development of the VUSEP separator, which ensures that the impregnating agent does not adhere to the conductor surface after being applied to the conductor for impregnation. For a more detailed description of winding terminals´cracking, see this article.
